1
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Sanfui S, Usman M, Roychowdhury A, Pramanik S, Garribba E, Gómez García CJ, Chen PPY, Rath SP. Bridge vs Terminal Cyano-coordination in Binuclear Cobalt Porphyrin Dimers: Interplay of Electrons between Metal and Ligand and Spin-Coupling via Bridge. Inorg Chem 2024; 63:15619-15633. [PMID: 39116010 DOI: 10.1021/acs.inorgchem.4c01150] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 08/10/2024]
Abstract
Three cyano-coordinated cobalt porphyrin dimers were synthesized and thoroughly characterized. The X-ray structure of the complexes reveals that cyanide binds in a terminal fashion in both the anti and trans isomers of ethane- and ethylene-bridged cobalt porphyrin dimers, while in the cis ethylene-bridged dimer, cyanides bind in both terminal and bridging modes. The nonconjugated ethane-bridged complex stabilizes exclusively a diamagnetic metal-centered oxidation of type CoIII(por)(CN)2 both in the solid and in solution. In contrast, the complexes with the conjugated ethylene-bridge contain signatures of both paramagnetic ligand-centered oxidation of the type CoII(por•+)(CN)2 and diamagnetic metal-centered oxidation of type CoIII(por)(CN)2 with the metal-centered oxidized species being the major component in the solid state as observed in XPS, while the ligand-centered oxidized species are present in a significant amount in solution. 1H NMR spectrum in solution displays two set of signals corresponding to the simultaneous presence of both the diamagnetic and paramagnetic species. EPR and magnetic investigation reveal that there is a moderate ferromagnetic coupling between the unpaired electrons of the low-spin CoII center and the porphyrin π-cation radical in CoII(por•+)(CN)2 species as well as an antiferromagnetic coupling between the two CoII(por•+) units through the ethylene and CN bridges.
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Affiliation(s)
- Sarnali Sanfui
- Department of Chemistry, Indian Institute of Technology Kanpur, Kanpur 208016, India
| | - Mohammad Usman
- Department of Chemistry, Indian Institute of Technology Kanpur, Kanpur 208016, India
| | - Arya Roychowdhury
- Department of Chemistry, Indian Institute of Technology Kanpur, Kanpur 208016, India
| | - Subhadip Pramanik
- Department of Chemistry, Indian Institute of Technology Kanpur, Kanpur 208016, India
| | - Eugenio Garribba
- Dipartimento di Medicina, Chirurgia e Farmacia, Viale San Pietro, Università di Sassari, Sassari I-07100, Italy
| | - Carlos J Gómez García
- Departamento de Química Inorgánica, Universidad de Valencia, C/Dr. Moliner 50, 46100 Burjassot, Valencia, Spain
| | - Peter P-Y Chen
- Department of Chemistry, National Chung-Hsing University, 250 Kuo Kuang Road, Taichung 402, Taiwan
| | - Sankar Prasad Rath
- Department of Chemistry, Indian Institute of Technology Kanpur, Kanpur 208016, India
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2
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Kopp SM, Redman AJ, Rončević I, Schröder L, Bogani L, Anderson HL, Timmel CR. Charge and Spin Transfer Dynamics in a Weakly Coupled Porphyrin Dimer. J Am Chem Soc 2024; 146:21476-21489. [PMID: 39042706 PMCID: PMC11311228 DOI: 10.1021/jacs.4c04186] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 07/25/2024]
Abstract
The dynamics of electron and spin transfer in the radical cation and photogenerated triplet states of a tetramethylbiphenyl-linked zinc-porphyrin dimer were investigated, so as to test the relevant parameters for the design of a single-molecule spin valve and the creation of a novel platform for the photogeneration of high-multiplicity spin states. We used a combination of multiple techniques, including variable-temperature continuous wave EPR, pulsed proton electron-nuclear double resonance (ENDOR), transient EPR, and optical spectroscopy. The conclusions are further supported by density functional theory (DFT) calculations and comparison to reference compounds. The low-temperature cw-EPR and room-temperature near-IR spectra of the dimer monocation demonstrate that the radical cation is spatially localized on one side of the dimer at any point in time, not coherently delocalized over both porphyrin units. The EPR spectra at 298 K reveal rapid hopping of the radical spin density between both sites of the dimer via reversible intramolecular electron transfer. The hyperfine interactions are modulated by electron transfer and can be quantified using ENDOR spectroscopy. This allowed simulation of the variable-temperature cw-EPR spectra with a two-site exchange model and provided information on the temperature-dependence of the electron transfer rate. The electron transfer rates range from about 10.0 MHz at 200 K to about 53.9 MHz at 298 K. The activation enthalpies Δ‡H of the electron transfer were determined as Δ‡H = 9.55 kJ mol-1 and Δ‡H = 5.67 kJ mol-1 in a 1:1:1 solvent mixture of CD2Cl2/toluene-d8/THF-d8 and in 2-methyltetrahydrofuran, respectively, consistent with a Robin-Day class II mixed valence compound. These results indicate that the interporphyrin electronic coupling in a tetramethylbiphenyl-linked porphyrin dimer is suitable for the backbone of a single-molecule spin valve. Investigation of the spin density distribution of the photogenerated triplet state of the Zn-porphyrin dimer reveals localization of the triplet spin density on a nanosecond time scale on one-half of the dimer at 20 K in 2-methyltetrahydrofuran and at 250 K in a polyvinylcarbazole film. This establishes the porphyrin dimer as a molecular platform for the formation of a localized, photogenerated triplet state on one porphyrin unit that is coupled to a second redox-active, ground-state porphyrin unit, which can be explored for the formation of high-multiplicity spin states.
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Affiliation(s)
- Sebastian M Kopp
- Centre for Advanced Electron Spin Resonance, Department of Chemistry, University of Oxford, Oxford, OX1 3QR, U.K
- Chemistry Research Laboratory, Department of Chemistry, University of Oxford, Oxford, OX1 3TA, U.K
| | - Ashley J Redman
- Centre for Advanced Electron Spin Resonance, Department of Chemistry, University of Oxford, Oxford, OX1 3QR, U.K
| | - Igor Rončević
- Chemistry Research Laboratory, Department of Chemistry, University of Oxford, Oxford, OX1 3TA, U.K
| | - Lisa Schröder
- Chemistry Research Laboratory, Department of Chemistry, University of Oxford, Oxford, OX1 3TA, U.K
| | - Lapo Bogani
- Department of Materials, University of Oxford, Oxford, OX1 3PH, U.K
| | - Harry L Anderson
- Chemistry Research Laboratory, Department of Chemistry, University of Oxford, Oxford, OX1 3TA, U.K
| | - Christiane R Timmel
- Centre for Advanced Electron Spin Resonance, Department of Chemistry, University of Oxford, Oxford, OX1 3QR, U.K
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3
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Fureraj I, Wega J, Balanikas E, Puji Pamungkas KK, Sakai N, Matile S, Vauthey E. Excitation-Wavelength-Dependent Photophysics of a Torsionally Disordered Push-Pull Dye. J Phys Chem Lett 2024:7857-7862. [PMID: 39052969 DOI: 10.1021/acs.jpclett.4c01840] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 07/27/2024]
Abstract
The torsional disorder of conjugated dyes in the electronic ground state can lead to inhomogeneous broadening of the S1 ←S0 absorption band, allowing for the selective photoexcitation of molecules with different amounts of distortion. Here, we investigate how this affects electronic transitions to upper excited states. We show that torsion of a core-alkynylated push-pull dye can have opposite effects on the oscillator strength of its lowest-energy transitions. Consequently, photoselection of planar and twisted molecules can be achieved by exciting in distinct absorption bands. Whereas this has limited effect in liquids due to fast planarization of the excited molecules, it strongly affects the overall photophysics in a polymeric environment, where torsional motion is hindered, allowing for the photoselection of molecules with different fluorescence quantum yields and intersystem-crossing dynamics.
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Affiliation(s)
- Ina Fureraj
- Department of Physical Chemistry, University of Geneva, CH-1211 Geneva, Switzerland
| | - Johannes Wega
- Department of Physical Chemistry, University of Geneva, CH-1211 Geneva, Switzerland
| | - Evangelos Balanikas
- Department of Physical Chemistry, University of Geneva, CH-1211 Geneva, Switzerland
| | | | - Naomi Sakai
- Department of Organic Chemistry, University of Geneva, CH-1211 Geneva, Switzerland
| | - Stefan Matile
- Department of Organic Chemistry, University of Geneva, CH-1211 Geneva, Switzerland
| | - Eric Vauthey
- Department of Physical Chemistry, University of Geneva, CH-1211 Geneva, Switzerland
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4
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Xu T, Liu T, Jing Y. Bifunctional oxygen reduction/evolution reaction electrocatalysts achieved by axial ligand modulation on two-dimensional porphyrin frameworks. Phys Chem Chem Phys 2024; 26:18707-18714. [PMID: 38932574 DOI: 10.1039/d4cp01235f] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/28/2024]
Abstract
Exploring efficient and low-cost oxygen reduction and oxygen evolution reaction (ORR/OER) bifunctional catalysts is essential for the development of energy storage and conversion devices. Herein, enlightened by the experimentally synthesized cobalt(II) meso-tetraethynylporphyrins (Co-TEP) molecule, we designed a novel 2D covalent organic framework (COF), namely a 2D Co-TEP monolayer, by dimensional expansion. The 2D Co-TEP monolayer, with Co atoms distributed separately and stabilized by uniform pyrrolic-N coordination, features metal-nitrogen-carbon single-atom catalyst activity and shows tunable catalytic activity for the electrochemical ORR/OER by axial ligand (O, OH, Cl, CN, CH3, NO, F) modulation. By means of the state-of-the-art constant-potential first-principles computations and microkinetic simulations, we demonstrated that 2D Co-TEP-CN exhibits good ORR/OER performance in both acidic and alkaline conditions. The difference between the onset-potential for the OER and the half-wave potential for the ORR is only 0.85 V at pH = 1, smaller than that of Pt/IrO2 electrocatalysts. The good electrocatalytic performance is maintained by replacing the center metal atoms with Mn, Fe and/or Ni. Our investigation highlights the role of the pyrrolic-N coordination and the ligands in improving the catalytic activity of 2D COFs and provides new insights into the rational design of efficient bifunctional ORR/OER catalysts.
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Affiliation(s)
- Tianze Xu
- Jiangsu Co-Innovation Centre of Efficient Processing and Utilization of Forest Resources, College of Chemical Engineering, Nanjing Forestry University, Nanjing 210037, China.
| | - Tianyang Liu
- Jiangsu Co-Innovation Centre of Efficient Processing and Utilization of Forest Resources, College of Chemical Engineering, Nanjing Forestry University, Nanjing 210037, China.
| | - Yu Jing
- Jiangsu Co-Innovation Centre of Efficient Processing and Utilization of Forest Resources, College of Chemical Engineering, Nanjing Forestry University, Nanjing 210037, China.
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5
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Chen Q, Lodi A, Zhang H, Gee A, Wang HI, Kong F, Clarke M, Edmondson M, Hart J, O'Shea JN, Stawski W, Baugh J, Narita A, Saywell A, Bonn M, Müllen K, Bogani L, Anderson HL. Porphyrin-fused graphene nanoribbons. Nat Chem 2024; 16:1133-1140. [PMID: 38459234 PMCID: PMC11230900 DOI: 10.1038/s41557-024-01477-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2023] [Accepted: 02/15/2024] [Indexed: 03/10/2024]
Abstract
Graphene nanoribbons (GNRs), nanometre-wide strips of graphene, are promising materials for fabricating electronic devices. Many GNRs have been reported, yet no scalable strategies are known for synthesizing GNRs with metal atoms and heteroaromatic units at precisely defined positions in the conjugated backbone, which would be valuable for tuning their optical, electronic and magnetic properties. Here we report the solution-phase synthesis of a porphyrin-fused graphene nanoribbon (PGNR). This PGNR has metalloporphyrins fused into a twisted fjord-edged GNR backbone; it consists of long chains (>100 nm), with a narrow optical bandgap (~1.0 eV) and high local charge mobility (>400 cm2 V-1 s-1 by terahertz spectroscopy). We use this PGNR to fabricate ambipolar field-effect transistors with appealing switching behaviour, and single-electron transistors displaying multiple Coulomb diamonds. These results open an avenue to π-extended nanostructures with engineerable electrical and magnetic properties by transposing the coordination chemistry of porphyrins into graphene nanoribbons.
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Affiliation(s)
- Qiang Chen
- Department of Chemistry, University of Oxford, Chemistry Research Laboratory, Oxford, UK.
- Max Planck Institute for Polymer Research, Mainz, Germany.
- Institute of Functional Nano & Soft Materials (FUNSOM), Soochow University, Suzhou, China.
| | | | - Heng Zhang
- Max Planck Institute for Polymer Research, Mainz, Germany
| | - Alex Gee
- Department of Materials, University of Oxford, Oxford, UK
| | - Hai I Wang
- Max Planck Institute for Polymer Research, Mainz, Germany
- Nanophotonics, Debye Institute for Nanomaterials Research, Utrecht University, Utrecht, the Netherlands
| | - Fanmiao Kong
- Department of Materials, University of Oxford, Oxford, UK
| | - Michael Clarke
- School of Physics & Astronomy, University of Nottingham, Nottingham, UK
| | - Matthew Edmondson
- School of Physics & Astronomy, University of Nottingham, Nottingham, UK
| | - Jack Hart
- School of Physics & Astronomy, University of Nottingham, Nottingham, UK
| | - James N O'Shea
- School of Physics & Astronomy, University of Nottingham, Nottingham, UK
| | - Wojciech Stawski
- Department of Chemistry, University of Oxford, Chemistry Research Laboratory, Oxford, UK
| | - Jonathan Baugh
- Institute for Quantum Computing, University of Waterloo, Waterloo, Ontario, Canada
| | | | - Alex Saywell
- School of Physics & Astronomy, University of Nottingham, Nottingham, UK
| | - Mischa Bonn
- Max Planck Institute for Polymer Research, Mainz, Germany
| | - Klaus Müllen
- Max Planck Institute for Polymer Research, Mainz, Germany
| | - Lapo Bogani
- Department of Materials, University of Oxford, Oxford, UK.
- Department of Chemistry & Physics, University of Florence, Sesto Fiorentino, Italy.
| | - Harry L Anderson
- Department of Chemistry, University of Oxford, Chemistry Research Laboratory, Oxford, UK.
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6
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Sarkar S, Tiwari RK, Samanta D, Guchhait T, Sañudo EC, Rajaraman G, Rath SP. Unusual Stabilisation of Remarkably Bent Tetra-Cationic Tetra-radical Intermolecular Fe(III) μ-Oxo Tetranuclear Complexes. Angew Chem Int Ed Engl 2024; 63:e202402344. [PMID: 38478415 DOI: 10.1002/anie.202402344] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2024] [Indexed: 04/24/2024]
Abstract
A hitherto unknown series of air stable, π-conjugated, remarkably bent tetra-cation tetra-radical intermolecular Fe(III) μ-oxo tetranuclear complex, isolated from the dication diradical diiron(III) porphyrin dimers, has been synthesised and spectroscopically characterised along with single crystal X-ray structure determination of two such molecules. These species facilitate long-range charge/radical delocalisation through the bridge across the entire tetranuclear unit manifesting an unusually intense NIR band. Assorted spin states of Fe(III) centres are stabilised within these unique tetranuclear frameworks: terminal six-coordinate iron centres stabilise the admixed intermediate spin states while the central five-coordinate iron centres stabilise the high-spin states. Variable temperature magnetic susceptibility measurements indicated strong antiferromagnetic coupling for the Fe(III)-O-Fe(III) unit while the exchange interactions between the Fe centres and the porphyrin π-cation radicals are weaker as supported both by magnetic data and DFT calculations. The nature of orbital overlap between the SOMOs of Fe(III) and π* orbital of the porphyrin was found to rationalise the observed exchange coupling, establishing such a complex magnetic exchange in this tetranuclear model with a significant bioinorganic relevance.
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Affiliation(s)
- Sabyasachi Sarkar
- Department of Chemistry, Indian Institute of Technology Kanpur, Kanpur, 208016, India
| | - Rupesh Kumar Tiwari
- Department of Chemistry, Indian Institute of Technology Bombay, Mumbai, 400076, India
| | - Deepannita Samanta
- Department of Chemistry, Indian Institute of Technology Kanpur, Kanpur, 208016, India
| | - Tapas Guchhait
- Department of Chemistry, Indian Institute of Technology Kanpur, Kanpur, 208016, India
| | - E Carolina Sañudo
- Secció de Química Inorgànica, Department de Química Inorgànica i Orgànica, Facultat de Química, Universitat de Barcelona, C/Martí i Franqués 1-11, 08028, Barcelona, Spain
- Institut de Nanociència i Nanotecnologia, IN2UB, Universitat de Barcelona, C/Martí i Franqués 1-11, 08028, Barcelona, Spain
| | - Gopalan Rajaraman
- Department of Chemistry, Indian Institute of Technology Bombay, Mumbai, 400076, India
| | - Sankar Prasad Rath
- Department of Chemistry, Indian Institute of Technology Kanpur, Kanpur, 208016, India
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7
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Shah SJ, Singh A, Goswami D, Ishida M, Rath SP. Reversible open-closed conformational switching of nano-size metalloporphyrin dimers triggered by light and temperature. Dalton Trans 2024; 53:6758-6765. [PMID: 38533553 DOI: 10.1039/d4dt00223g] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/28/2024]
Abstract
The current work demonstrates the reversible control of substantial molecular motion in 'nano-sized' molecules, where two structural isomers can 'open' and 'close' their cavities in response to light or heat. The isomers differ widely in their photophysical properties, including colour, polarity, two-photon absorption and π-conjugation, and can easily be separated through column chromatography and thus have wide applicability.
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Affiliation(s)
- Syed Jehanger Shah
- Department of Chemistry, Indian Institute of Technology Kanpur, Kanpur 208016, India.
| | - Ajitesh Singh
- Department of Chemistry, Indian Institute of Technology Kanpur, Kanpur 208016, India.
| | - Debabrata Goswami
- Department of Chemistry, Indian Institute of Technology Kanpur, Kanpur 208016, India.
| | - Masatoshi Ishida
- Department of Chemistry, Graduate School of Science, Tokyo Metropolitan University, Hachioji, Tokyo 192-0397, Japan
| | - Sankar Prasad Rath
- Department of Chemistry, Indian Institute of Technology Kanpur, Kanpur 208016, India.
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8
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Tariq A, Arif A, Akram M, Latif U, Nawaz MH, Andreescu S, Zhang H, Hayat A. Tailoring molecular recognition in predesigned multifunctional enzyme mimicking porphyrin imprinted interface for high affinity and differential selectivity; sensing etoposide in lung cancer patients. Biosens Bioelectron 2024; 245:115833. [PMID: 37984317 DOI: 10.1016/j.bios.2023.115833] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/12/2023] [Revised: 11/03/2023] [Accepted: 11/09/2023] [Indexed: 11/22/2023]
Abstract
Nanozymes are cost-effective and robust but they lack specificity and selectivity, limiting their potential practical applications. Herein, molecularly imprinted polymers (MIPs) were grown in combination with multifunctional 5,10,15,20-tetrakis(4-hydroxyphenyl)-21H,23H-porphyrin (THPP) oxidase-like nanozyme to engineer THPP@MIP interface with high affinities and differential selectivity for structurally related target analytes. THPP nanozyme displayed a high level of predefined binding affinity for etoposide (ETO), and served as a predesigned functional monomer to rationally tailor the selectivity of THPP@MIP surface in the presence of different guest molecules. THPP nanozyme in combination with conventional monomers was imprinted on a portable and disposable cellulose paper matrix under UV light to create a UV-cured imprinted interface for optical detection of ETO. The THPP@MIP enzyme mimicking interface, having ETO specific and selective target recognition pockets, catalyzed the oxidation of colorless 3,3',5,5'-tetramethylbenzidine (TMB) to generate visible blue oxidized TMB (oxTMB) without exogenous hydrogen peroxide (H2O2). The ETO binding on the THPP@MIP surface blocked the channels for TMB access to THPP cavities. The THPP@MIP sensor permitted to detect ETO in the linear range of 0.005-10 μg mL-1, with a limit of detection (LoD) of 0.002 μg mL-1, and showed a remarkable specificity and selectivity against other drug molecules. Furthermore, the THPP@MIP sensor successfully differentiated the serum samples of lung cancer patients and healthy volunteers. The obtained results were validated with standard High performance liquid chromatography-mass spectrometry (HPLC/MS) analysis of the serum samples. Additionally, ETO injection/infusion solutions and ETO-free serum samples were used to perform the matrix effect and recovery studies. This work demonstrates that molecular imprinting with predesigned, enzyme mimicking, high-affinity functional monomer can serve as a highly selective and specific universal interface for broad spectrum sensing applications in various analytical domains.
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Affiliation(s)
- Aqsa Tariq
- State Key Laboratory of Biobased Material and Green Papermaking, College of Food Science and Engineering, Qilu University of Technology, Shandong Academy of Science, PO Box 250353, Jinan, Shandong, China; Interdisciplinary Research Center in Biomedical Materials (IRCBM), COMSATS University Islamabad (CUI), Lahore, 54000, Pakistan; Department of Basic and Applied Chemistry, Faculty of Science and Technology, University of Central Punjab, Lahore, Pakistan
| | - Amina Arif
- Department of Basic and Applied Chemistry, Faculty of Science and Technology, University of Central Punjab, Lahore, Pakistan
| | - Muhammad Akram
- Interdisciplinary Research Center in Biomedical Materials (IRCBM), COMSATS University Islamabad (CUI), Lahore, 54000, Pakistan
| | - Usman Latif
- Interdisciplinary Research Center in Biomedical Materials (IRCBM), COMSATS University Islamabad (CUI), Lahore, 54000, Pakistan
| | - Mian Hasnain Nawaz
- Interdisciplinary Research Center in Biomedical Materials (IRCBM), COMSATS University Islamabad (CUI), Lahore, 54000, Pakistan
| | - Silvana Andreescu
- Department of Chemistry and Biomolecular Science, Clarkson University, Potsdam, NY, 13699-5810, USA
| | - Hongxia Zhang
- State Key Laboratory of Biobased Material and Green Papermaking, College of Food Science and Engineering, Qilu University of Technology, Shandong Academy of Science, PO Box 250353, Jinan, Shandong, China.
| | - Akhtar Hayat
- State Key Laboratory of Biobased Material and Green Papermaking, College of Food Science and Engineering, Qilu University of Technology, Shandong Academy of Science, PO Box 250353, Jinan, Shandong, China; Interdisciplinary Research Center in Biomedical Materials (IRCBM), COMSATS University Islamabad (CUI), Lahore, 54000, Pakistan.
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9
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Mondal S, Chowdhury U, Dey S, Habib M, Mora Perez C, Frauenheim T, Sarkar R, Pal S, Prezhdo OV. Controlling Charge Carrier Dynamics in Porphyrin Nanorings by Optically Active Templates. J Phys Chem Lett 2023; 14:11384-11392. [PMID: 38078872 PMCID: PMC10749466 DOI: 10.1021/acs.jpclett.3c03304] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/23/2023] [Revised: 12/01/2023] [Accepted: 12/01/2023] [Indexed: 12/22/2023]
Abstract
Understanding the dynamics of photogenerated charge carriers is essential for enhancing the performance of solar and optoelectronic devices. Using atomistic quantum dynamics simulations, we demonstrate that a short π-conjugated optically active template can be used to control hot carrier relaxation, charge carrier separation, and carrier recombination in light-harvesting porphyrin nanorings. Relaxation of hot holes is slowed by 60% with an optically active template compared to that with an analogous optically inactive template. Both systems exhibit subpicosecond electron transfer from the photoactive core to the templates. Notably, charge recombination is suppressed 6-fold by the optically active template. The atomistic time-domain simulations rationalize these effects by the extent of electron and hole localization, modification of the density of states, participation of distinct vibrational motions, and changes in quantum coherence. Extension of the hot carrier lifetime and reduction of charge carrier recombination, without hampering charge separation, demonstrate a strategy for enhancing efficiencies of energy materials with optically active templates.
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Affiliation(s)
- Shrabanti Mondal
- Department
of Chemistry, University of Gour Banga, Malda 732103, India
| | - Uttam Chowdhury
- Department
of Chemistry, University of Gour Banga, Malda 732103, India
| | - Subhajit Dey
- Department
of Chemistry, University of Gour Banga, Malda 732103, India
| | - Md Habib
- Department
of Chemistry, University of Gour Banga, Malda 732103, India
- Department
of Chemistry, Sripat Singh College, Jiaganj 742122, India
| | - Carlos Mora Perez
- Department
of Chemistry, University of Southern California, Los Angeles, California 90089, United States
| | - Thomas Frauenheim
- Bremen
Center
for Computational Materials Science, Universität
Bremen, Bremen 28359, Germany
- Beijing
Computational Science Research Center, Beijing 100193, China
- Shenzhen
JL Computational Science and Applied Research Institute, Shenzhen 518109, China
| | - Ritabrata Sarkar
- Department
of Chemistry, University of Gour Banga, Malda 732103, India
- Bremen
Center
for Computational Materials Science, Universität
Bremen, Bremen 28359, Germany
| | - Sougata Pal
- Department
of Chemistry, University of Gour Banga, Malda 732103, India
| | - Oleg V. Prezhdo
- Department
of Chemistry, University of Southern California, Los Angeles, California 90089, United States
- Department
of Physics and Astronomy, University of
Southern California, Los Angeles, California 90089, United States
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10
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Shah SJ, Pandit YA, Garribba E, Ishida M, Rath SP. Stable Dication Diradicals of Triply Fused Metallo Chlorin-Porphyrin Heterodimers: Impact of the Bridge on the Control of Spin Coupling to Reactivity. Chemistry 2023; 29:e202301963. [PMID: 37602834 DOI: 10.1002/chem.202301963] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/20/2023] [Revised: 08/16/2023] [Accepted: 08/16/2023] [Indexed: 08/22/2023]
Abstract
We report an unexpected rearrangement, controlled by the nature of the bridge, leading to the formation of novel, remarkably stable triply fused dinickel(II)/dicopper(II) chlorin-porphyrin dication diradical heterodimers in excellent yields. Here, a dipyrromethene bridge gets completely fused between two porphyrin macrocycles with two new C-C and one C-N bonds. The two macrocycles exhibit extensive π-conjugation through the bridge, which results in an antiferromagnetic coupling between the two π-cation radicals. In addition, the macrocyclic distortion also favours a rare intramolecular ferromagnetic interaction between the CuII and π-cation radical spins to form a triplet state. The structural and electronic perturbation in the unconjugated dication diradical possibly enables the bridging pyrrolic nitrogen to undergo a nucleophilic attack at the nearby β-carbon of the porphyrin π-cation radical with a computed free energy barrier of >20 kcal mol-1 which was supplied in the form of reflux condition to initiate such a rearrangement process. UV-vis, EPR and ESI-MS spectroscopies were used to monitor the rearrangement process in situ in order to identify the key reactive intermediates leading to such an unusual transformation.
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Affiliation(s)
- Syed Jehanger Shah
- Department of Chemistry, Indian Institute of Technology Kanpur, Kanpur, 208016, India
| | - Younis Ahmad Pandit
- Department of Chemistry, Indian Institute of Technology Kanpur, Kanpur, 208016, India
| | - Eugenio Garribba
- Dipartimento di Medicina, Chirurgia e Farmacia, Università di Sassari, Viale San Pietro, 07100, Sassari, Italy
| | - Masatoshi Ishida
- Department of Chemistry, Graduate School of Science, Tokyo Metropolitan University, Tokyo, 192-0397, Japan
| | - Sankar Prasad Rath
- Department of Chemistry, Indian Institute of Technology Kanpur, Kanpur, 208016, India
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11
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Nicolaidou E, Parker AW, Sazanovich IV, Towrie M, Hayes SC. Unraveling Excited State Dynamics of a Single-Stranded DNA-Assembled Conjugated Polyelectrolyte. J Phys Chem Lett 2023; 14:9794-9803. [PMID: 37883808 PMCID: PMC10641883 DOI: 10.1021/acs.jpclett.3c01803] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/02/2023] [Revised: 10/21/2023] [Accepted: 10/23/2023] [Indexed: 10/28/2023]
Abstract
Conformational templating of conjugated polyelectrolytes with single-stranded DNAs (ssDNAs) has the prospect of tailoring excited state dynamics for specific optoelectronic applications. We use ultrafast time-resolved infrared spectroscopy to study the photophysics of a cationic polythiophene assembled with different ssDNAs, inducing distinct conformations (flexible disordered structures vs more rigid complexes with increased backbone planarity). Intrachain polarons are always produced upon selective excitation of the polymer, the extent being dependent on backbone torsional order. Polaron formation and decay were monitored through evolution of IR-active vibrational modes that interfere with mid-IR polaron electronic absorption giving rise to Fano-antiresonances. Selective UV excitation of ssDNAs revealed that stacking interactions between thiophene rings and nucleic acid bases can promote the formation of an intermolecular charge transfer complex. The findings inform designers of functional conjugated polymers by identifying that involvement of the scaffold in the photophysics needs to be considered when developing such structures for optoelectronic applications.
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Affiliation(s)
- Eliana Nicolaidou
- Department
of Chemistry, University of Cyprus, P.O. Box 20537, 1678 Nicosia, Cyprus
| | - Anthony W. Parker
- Central
Laser Facility, Research Complex at Harwell, Science and Technology
Facilities Council, Rutherford Appleton Laboratory, Harwell Oxford, Didcot, Oxfordshire OX11 0QX, U.K.
| | - Igor V. Sazanovich
- Central
Laser Facility, Research Complex at Harwell, Science and Technology
Facilities Council, Rutherford Appleton Laboratory, Harwell Oxford, Didcot, Oxfordshire OX11 0QX, U.K.
| | - Michael Towrie
- Central
Laser Facility, Research Complex at Harwell, Science and Technology
Facilities Council, Rutherford Appleton Laboratory, Harwell Oxford, Didcot, Oxfordshire OX11 0QX, U.K.
| | - Sophia C. Hayes
- Department
of Chemistry, University of Cyprus, P.O. Box 20537, 1678 Nicosia, Cyprus
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12
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Moise G, Redman AJ, Richert S, Myers WK, Bulut I, Bolls PS, Rickhaus M, Sun J, Anderson HL, Timmel CR. The impact of spin-orbit coupling on fine-structure and spin polarisation in photoexcited porphyrin triplet states. JOURNAL OF MAGNETIC RESONANCE (SAN DIEGO, CALIF. : 1997) 2023; 355:107546. [PMID: 37797559 DOI: 10.1016/j.jmr.2023.107546] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/15/2023] [Revised: 08/24/2023] [Accepted: 08/31/2023] [Indexed: 10/07/2023]
Abstract
The photoexcited triplet states of porphyrins show great promise for applications in the fields of opto-electronics, photonics, molecular wires, and spintronics. The magnetic properties of porphyrin triplet states are most conveniently studied by time-resolved continuous wave and pulse electron spin resonance (ESR). This family of techniques is singularly able to probe small yet essential details of triplet states: zero-field splittings, g-anisotropy, spin polarisation, and hyperfine interactions. These characteristics are linked to spin-orbit coupling (SOC) which is known to have a strong influence on photophysical properties such as intersystem crossing rates. The present study explores SOC effects induced by the presence of Pd2+ in various porphyrin architectures. In particular, the impact of this relativistic interaction on triplet state fine-structure and spin polarisation is investigated. These properties are probed using time-resolved ESR complemented by electron-nuclear double resonance. The findings of this study could influence the future design of molecular spintronic devices. The Pd2+ ion may be incorporated into porphyrin molecular wires as a way of controlling spin polarisation.
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Affiliation(s)
- Gabriel Moise
- Centre for Advanced Electron Spin Resonance (CAESR), Inorganic Chemistry Laboratory, Department of Chemistry, University of Oxford, South Parks Road, Oxford, OX1 3QR, United Kingdom.
| | - Ashley J Redman
- Centre for Advanced Electron Spin Resonance (CAESR), Inorganic Chemistry Laboratory, Department of Chemistry, University of Oxford, South Parks Road, Oxford, OX1 3QR, United Kingdom
| | - Sabine Richert
- Centre for Advanced Electron Spin Resonance (CAESR), Inorganic Chemistry Laboratory, Department of Chemistry, University of Oxford, South Parks Road, Oxford, OX1 3QR, United Kingdom; Institute of Physical Chemistry, University of Freiburg, Albertstraße 21, Freiburg, 79104, Germany
| | - William K Myers
- Centre for Advanced Electron Spin Resonance (CAESR), Inorganic Chemistry Laboratory, Department of Chemistry, University of Oxford, South Parks Road, Oxford, OX1 3QR, United Kingdom
| | - Ibrahim Bulut
- Chemistry Research Laboratory, Department of Chemistry, University of Oxford, 12 Mansfield Road, Oxford, OX1 3TA, United Kingdom
| | - Pernille S Bolls
- Chemistry Research Laboratory, Department of Chemistry, University of Oxford, 12 Mansfield Road, Oxford, OX1 3TA, United Kingdom
| | - Michel Rickhaus
- Chemistry Research Laboratory, Department of Chemistry, University of Oxford, 12 Mansfield Road, Oxford, OX1 3TA, United Kingdom
| | - Jibin Sun
- Chemistry Research Laboratory, Department of Chemistry, University of Oxford, 12 Mansfield Road, Oxford, OX1 3TA, United Kingdom
| | - Harry L Anderson
- Chemistry Research Laboratory, Department of Chemistry, University of Oxford, 12 Mansfield Road, Oxford, OX1 3TA, United Kingdom
| | - Christiane R Timmel
- Centre for Advanced Electron Spin Resonance (CAESR), Inorganic Chemistry Laboratory, Department of Chemistry, University of Oxford, South Parks Road, Oxford, OX1 3QR, United Kingdom.
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13
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Mahmood A, Dimitrova M, Sundholm D. Current-Density Calculations on Zn-Porphyrin 40 Nanorings. J Phys Chem A 2023; 127:7452-7459. [PMID: 37665662 PMCID: PMC10510378 DOI: 10.1021/acs.jpca.3c03564] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/26/2023] [Revised: 08/04/2023] [Indexed: 09/06/2023]
Abstract
Two porphyrinoid nanorings have been studied computationally. They were built by linking 40 Zn-porphyrin units with butadiyne bridges. The molecular structures belonging to the D40h point group were fully optimized with the Turbomole program at the density functional theory (DFT) level using the B3LYP functional and the def2-SVP basis sets. The aromatic character was studied at the DFT level by calculating the magnetically induced current-density (MICD) susceptibility using the GIMIC program. The neutral molecules are globally non-aromatic with aromatic Zn-porphyrin units. Charged nanorings could not be studied because almost degenerate frontier orbitals led to vanishing optical gaps for the cations. Since DFT calculations of the MICD are computationally expensive, we also calculated the MICD using three pseudo-π models. Appropriate pseudo-π models were constructed by removing the outer hydrogen atoms and replacing all carbon and nitrogen atoms with hydrogen atoms. The central Zn atom was either replaced with a beryllium atom or with two inner hydrogen atoms. Calculations with the computationally inexpensive pseudo-π models yielded qualitatively the same magnetic response as obtained in the all-electron calculations.
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Affiliation(s)
- Atif Mahmood
- Department of Chemistry, University
of Helsinki, P.O. Box 55, A. I. Virtasen Aukio 1, FIN-00014 Helsinki, Finland
| | - Maria Dimitrova
- Department of Chemistry, University
of Helsinki, P.O. Box 55, A. I. Virtasen Aukio 1, FIN-00014 Helsinki, Finland
| | - Dage Sundholm
- Department of Chemistry, University
of Helsinki, P.O. Box 55, A. I. Virtasen Aukio 1, FIN-00014 Helsinki, Finland
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14
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Gómez-Gómez M, Labella J, Torres T. Borylated Subphthalocyanines: Versatile Precursors for the Preparation of Functional Bowl-Shaped Aromatics. Chemistry 2023; 29:e202301782. [PMID: 37350310 DOI: 10.1002/chem.202301782] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/04/2023] [Revised: 06/22/2023] [Accepted: 06/23/2023] [Indexed: 06/24/2023]
Abstract
The peripheral borylation of porphyrinoids has become a key step to prepare advanced functional materials. This study reports the synthesis, electronic properties, and reactivity of borylated subphthalocyanines. These compounds, which are prepared by Suzuki-Miyaura borylation in excellent yields, are easily purified, display a great stability, and serve as powerful starting materials for the post-functionalization of SubPcs via cross-coupling reactions. Remarkably, this novel approach is more efficient than the methodologies already described and enables the preparation of exotic systems, such as SubPc dimeric species linked by C-C bonds, which are not accessible so far and present promising properties for optoelectronic devices.
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Affiliation(s)
- Marta Gómez-Gómez
- Department of Organic Chemistry, Universidad Autónoma de Madrid, Campus de Cantoblanco, C/ Francisco Tomás y Valiente 7, 28049, Madrid, Spain
| | - Jorge Labella
- Department of Organic Chemistry, Universidad Autónoma de Madrid, Campus de Cantoblanco, C/ Francisco Tomás y Valiente 7, 28049, Madrid, Spain
| | - Tomás Torres
- Department of Organic Chemistry, Universidad Autónoma de Madrid, Campus de Cantoblanco, C/ Francisco Tomás y Valiente 7, 28049, Madrid, Spain
- Institute for Advanced Research in Chemical Sciences (IAdChem), Universidad Autónoma de Madrid, Madrid, Spain
- IMDEA - Nanociencia, C/ Faraday 9, Campus de Cantoblanco, 28049, Madrid, Spain
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15
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Stanley PM, Sixt F, Warnan J. Decoupled Solar Energy Storage and Dark Photocatalysis in a 3D Metal-Organic Framework. ADVANCED MATERIALS (DEERFIELD BEACH, FLA.) 2023; 35:e2207280. [PMID: 36217842 DOI: 10.1002/adma.202207280] [Citation(s) in RCA: 6] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/10/2022] [Revised: 09/20/2022] [Indexed: 06/16/2023]
Abstract
Materials enabling solar energy conversion and long-term storage for readily available electrical and chemical energy are key for off-grid energy distribution. Herein, the specific confinement of a rhenium coordination complex in a metal-organic framework (MOF) unlocks a unique electron accumulating property under visible-light irradiation. About 15 C gMOF -1 of electric charges can be concentrated and stored for over four weeks without loss. Decoupled, on-demand discharge for electrochemical reactions and H2 evolution catalysis is shown and light-driven recharging can be conducted for >10 cycles with ≈90% of the initial charging capacity retained. Experimental investigations and theoretical calculations link electron trapping to MOF-induced geometry constraints as well as the coordination environment of the Re-center, highlighting the key role of MOF confinement on molecular guests. This study serves as the seminal report on 3D porous colloids achieving photoaccumulation of long-lived electrons, unlocking dark photocatalysis, and a path toward solar capacitor and solar battery systems.
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Affiliation(s)
- Philip M Stanley
- Chair of Inorganic and Metal-Organic Chemistry, Department of Chemistry, and Catalysis, Research Center (CRC), TUM School of Natural Sciences, Technical University of Munich, Garching, Germany
| | - Florian Sixt
- Chair of Inorganic and Metal-Organic Chemistry, Department of Chemistry, and Catalysis, Research Center (CRC), TUM School of Natural Sciences, Technical University of Munich, Garching, Germany
| | - Julien Warnan
- Chair of Inorganic and Metal-Organic Chemistry, Department of Chemistry, and Catalysis, Research Center (CRC), TUM School of Natural Sciences, Technical University of Munich, Garching, Germany
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16
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Cai F, Ye K, Chen M, Tian Y, Chen P, Lin H, Chen T, Ma L. High-dimensional zinc porphyrin nanoframeworks as efficient radiosensitizers for cervical cancer. CHINESE CHEM LETT 2022. [DOI: 10.1016/j.cclet.2022.107945] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
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17
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Harchol A, Barak Y, Hughes KE, Hartstein KH, Jöbsis HJ, Prins PT, de Mello Donegá C, Gamelin DR, Lifshitz E. Optically Detected Magnetic Resonance Spectroscopy of Cu-Doped CdSe/CdS and CuInS 2 Colloidal Quantum Dots. ACS NANO 2022; 16:12866-12877. [PMID: 35913892 DOI: 10.1021/acsnano.2c05130] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/15/2023]
Abstract
Copper-doped II-VI and copper-based I-III-VI2 colloidal quantum dots (CQDs) have been at the forefront of interest in nanocrystals over the past decade, attributable to their optically activated copper states. However, the related recombination mechanisms are still unclear. The current work elaborates on recombination processes in such materials by following the spin properties of copper-doped CdSe/CdS (Cu@CdSe/CdS) and of CuInS2 and CuInS2/(CdS, ZnS) core/shell CQDs using continuous-wave and time-resolved optically detected magnetic resonance (ODMR) spectroscopy. The Cu@CdSe/CdS ODMR showed two distinct resonances with different g factors and spin relaxation times. The best fit by a spin Hamiltonian simulation suggests that emission comes from recombination of a delocalized electron at the conduction band edge with a hole trapped in a Cu2+ site with a weak exchange coupling between the two spins. The ODMR spectra of CuInS2 CQDs (with and without shells) differ significantly from those of the copper-doped II-VI CQDs. They are comprised of a primary resonance accompanied by another resonance at half-field, with a strong correlation between the two, indicating the involvement of a triplet exciton and hence stronger electron-hole exchange coupling than in the doped core/shell CQDs. The spin Hamiltonian simulation shows that the hole is again associated with a photogenerated Cu2+ site. The electron resides near this Cu2+ site, and its ODMR spectrum shows contributions from superhyperfine coupling to neighboring indium atoms. These observations are consistent with the occurrence of a self-trapped exciton associated with the copper site. The results presented here support models under debate for over a decade and help define the magneto-optical properties of these important materials.
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Affiliation(s)
- Adi Harchol
- Schulich Faculty of Chemistry, Solid State Institute, Russell Berrie Nanotechnology Institute, Technion-Israel Institute of Technology, Haifa 3200003, Israel
| | - Yahel Barak
- Schulich Faculty of Chemistry, Solid State Institute, Russell Berrie Nanotechnology Institute, Technion-Israel Institute of Technology, Haifa 3200003, Israel
| | - Kira E Hughes
- Department of Chemistry, University of Washington, Seattle, Washington 98195-1700, United States
| | - Kimberly H Hartstein
- Department of Chemistry, University of Washington, Seattle, Washington 98195-1700, United States
| | - Huygen J Jöbsis
- Condensed Matter and Interfaces, Debye Institute for Nanomaterials Science, Utrecht University, 3584 CC Utrecht, The Netherlands
| | - P Tim Prins
- Condensed Matter and Interfaces, Debye Institute for Nanomaterials Science, Utrecht University, 3584 CC Utrecht, The Netherlands
| | - Celso de Mello Donegá
- Condensed Matter and Interfaces, Debye Institute for Nanomaterials Science, Utrecht University, 3584 CC Utrecht, The Netherlands
| | - Daniel R Gamelin
- Department of Chemistry, University of Washington, Seattle, Washington 98195-1700, United States
| | - Efrat Lifshitz
- Schulich Faculty of Chemistry, Solid State Institute, Russell Berrie Nanotechnology Institute, Technion-Israel Institute of Technology, Haifa 3200003, Israel
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18
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Sanfui S, Usman M, Sarkar S, Pramanik S, Garribba E, Rath SP. Highly Oxidized Cobalt Porphyrin Dimer: Control of Spin Coupling via a Bridge. Inorg Chem 2022; 61:8419-8430. [PMID: 35613476 DOI: 10.1021/acs.inorgchem.1c03807] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
A cobalt porphyrin dimer is constructed in which two Co(II)porphyrins are connected covalently through a redox-active diethylpyrrole moiety via a flexible but "nonconjugated" methylene bridge. Upon oxidation with even a mild oxidant such as iodine, each cobalt(II) center and porphyrin ring undergo 1e- oxidation, leading to the formation of a 4e--oxidized cobalt(III)porphyrin dication diradical complex. Other oxidants such as Cl2 and Br2 also produce similar results. To stabilize such highly oxidized dication diradicals, the "nonconjugated" methylene spacer undergoes a facile and spontaneous oxidation to form a methine group with a drastic structural change, thereby making the bridge fully π-conjugated and enabling through-bond communication. This results in a strong spin coupling between two π-cation radicals which stabilizes the singlet state. The experimental observations are also strongly supported by extensive density functional theory calculations. The present study highlights the crucial role played by the nature of the bridge in the long-range electronic communication.
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Affiliation(s)
- Sarnali Sanfui
- Department of Chemistry, Indian Institute of Technology Kanpur, Kanpur 208016, India
| | - Mohammad Usman
- Department of Chemistry, Indian Institute of Technology Kanpur, Kanpur 208016, India
| | - Sabyasachi Sarkar
- Department of Chemistry, Indian Institute of Technology Kanpur, Kanpur 208016, India
| | - Subhadip Pramanik
- Department of Chemistry, Indian Institute of Technology Kanpur, Kanpur 208016, India
| | - Eugenio Garribba
- Dipartimento di Scienze Mediche, Chirurgiche e Sperimentali, Università di Sassari, Viale San Pietro, Sassari I-07100, Italy
| | - Sankar Prasad Rath
- Department of Chemistry, Indian Institute of Technology Kanpur, Kanpur 208016, India
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19
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Sun R, Wang T, Ren X, Zhang L, Zhou Y, Huang C. Third-order optical nonlinearities of zinc porphyrins accommodated in the cavity of a doughnut-like molybdenum crown cluster. Dalton Trans 2022; 51:7966-7974. [PMID: 35546497 DOI: 10.1039/d2dt00367h] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
In this paper, three zinc porphyrins bearing carboxyl, amino or hydroxyl groups on the porphyrin ring, namely, 5,10,15,20-tetra(4-carboxyphenyl) zinc porphyrin (ZnTCPP), 5,10,15,20-tetra(4-hydroxyphenyl) zinc porphyrin (ZnTHPP) and 5,10,15,20-tetra(4-aminophenyl) zinc porphyrin (ZnTAPP), reacted with the doughnut-like molybdenum crown cluster [(MoO3)176(H2O)63(CH3OH)17H16]16- (denoted as {Mo176}), resulting in the formation of three porphyrin-polyoxometalate hybrids (denoted as hybrids 1-3), respectively, with the ratio of {Mo176} to the porphyrin molecules in each compound being 1 : 3. Compared with the corresponding parent porphyrins, the fluorescence quenching efficiency of hybrid 1, hybrid 2 and hybrid 3 was found to be 51%, 58% and 66%, respectively, indicating electron/energy transfer occurring from the porphyrin moiety to the POM moiety. Z-Scan experimental results showed that the three porphyrins and hybrids 1-3 exhibited nonlinear reverse saturated absorption and self-defocusing properties. The molecular second hyperpolarizability (γ) values of hybrids 1-3 (7.38 × 10-27, 7.26 × 10-27 and 4.26 × 10-27 (esu)) are higher than those of the corresponding porphyrins (1.18 × 10-27, 1.34 × 10-27 and 1.36 × 10-27 (esu)), indicating that the doughnut-like molybdenum crown cluster in the hybrids 1-3 improved the third-order optical nonlinearities of the accommodated H-aggregate of the zinc porphyrin molecules, wherein the optical nonlinearities of the porphyrin with the electron-withdrawing functional group of -COOH (γ = 7.38 × 10-27 for hybrid 1vs. γ = 1.18 × 10-27 for ZnTCPP) were enhanced the most. In addition, studies on the optical limiting properties of hybrid 1 and hybrid 2 showed that the nonlinear attenuation factor (NAF) of both hybrid 1 and hybrid 2 was larger than that of their corresponding porphyrins (NAF = 5.65 for hybrid 1vs. 1.82 for ZnTCPP) and the limiting threshold of hybrid 1 and hybrid 2 can reach 0.3 J cm-2 and 0.32 J cm-2, which proved that hybrids 1 and 2 are potential optical limiting materials.
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Affiliation(s)
- Ran Sun
- State Key Laboratory of Chemical Resource Engineering, College of Chemistry, Beijing University of Chemical Technology, Beijing 100029, China.
| | - Ting Wang
- State Key Laboratory of Chemical Resource Engineering, College of Chemistry, Beijing University of Chemical Technology, Beijing 100029, China.
| | - Xiaoyu Ren
- State Key Laboratory of Chemical Resource Engineering, College of Chemistry, Beijing University of Chemical Technology, Beijing 100029, China.
| | - Lijuan Zhang
- State Key Laboratory of Chemical Resource Engineering, College of Chemistry, Beijing University of Chemical Technology, Beijing 100029, China.
| | - Yunshan Zhou
- State Key Laboratory of Chemical Resource Engineering, College of Chemistry, Beijing University of Chemical Technology, Beijing 100029, China.
| | - Chengcheng Huang
- State Key Laboratory of Chemical Resource Engineering, College of Chemistry, Beijing University of Chemical Technology, Beijing 100029, China.
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20
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Pandit YA, Shah SJ, Usman M, Sarkar S, Garribba E, Rath SP. Long-Range Intramolecular Spin Coupling through a Redox-Active Bridge upon Stepwise Oxidations: Control and Effect of Metal Ions. Inorg Chem 2022; 61:5270-5282. [PMID: 35323011 DOI: 10.1021/acs.inorgchem.1c03945] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Dinickel(II) and dicopper(II) porphyrin dimers have been constructed in which two metalloporphyrin units are widely separated by a long unconjugated dipyrrole bridge. Two macrocycles are aligned somewhat orthogonally to each other, while oxidation of the bridge generates a fully π-conjugated butterfly-like structure, which, in turn, upon stepwise oxidations by stronger oxidants result in the formation of the corresponding one- and two-electron-oxidized species exhibiting unusual long-range charge/radical delocalization to produce intense absorptions in the near-infrared (NIR) region and electron paramagnetic resonance (EPR) signals of a triplet state due to interaction between the unpaired spins on the Cu(II) ions. Although the two metal centers have a large physical separation through the bridge (more than 16 Å), they share electrons efficiently between them, behaving as a single unit rather than two independent centers. Detailed UV-vis-NIR, electrospray ionization mass spectrometry, IR, variable-temperature magnetic study, and EPR spectroscopic investigations along with X-ray structure determination of unconjugated, conjugated, and one electron-oxidized complexes have been exploited to demonstrate the long-range electronic communication through the bridge. The experimental observations are also supported by density functional theory (DFT) and time-dependent DFT calculations. The present study highlights the crucial roles played by a redox-active bridge and metal in controlling the long-range electronic communication.
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Affiliation(s)
- Younis Ahmad Pandit
- Department of Chemistry, Indian Institute of Technology Kanpur, Kanpur 208016, India
| | - Syed Jehanger Shah
- Department of Chemistry, Indian Institute of Technology Kanpur, Kanpur 208016, India
| | - Mohammad Usman
- Department of Chemistry, Indian Institute of Technology Kanpur, Kanpur 208016, India
| | - Sabyasachi Sarkar
- Department of Chemistry, Indian Institute of Technology Kanpur, Kanpur 208016, India
| | - Eugenio Garribba
- Dipartimento di Scienze Mediche, Chirurgiche e Sperimentali, Università di Sassari, Viale San Pietro, Sassari I-07100, Italy
| | - Sankar Prasad Rath
- Department of Chemistry, Indian Institute of Technology Kanpur, Kanpur 208016, India
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21
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Casademont‐Reig I, Guerrero‐Avilés R, Ramos‐Cordoba E, Torrent‐Sucarrat M, Matito E. How Aromatic Are Molecular Nanorings? The Case of a Six-Porphyrin Nanoring*. Angew Chem Int Ed Engl 2021; 60:24080-24088. [PMID: 34260804 PMCID: PMC8596448 DOI: 10.1002/anie.202108997] [Citation(s) in RCA: 28] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/06/2021] [Indexed: 01/15/2023]
Abstract
Large conjugated rings with persistent currents are novel promising structures in molecular-scale electronics. A six-porphyrin nanoring structure that allegedly sustained an aromatic ring current involving 78π electrons was recently synthesized. We provide here compelling evidence that this molecule is not aromatic, contrary to what was inferred from the analysis of 1 H-NMR data and computational calculations that suffer from large delocalization errors. The main reason behind the absence of an aromatic ring current in these nanorings is the low delocalization in the transition from the porphyrins to the bridging butadiyne linkers, which disrupts the overall conjugated circuit. These results highlight the importance of choosing a suitable computational method to study large conjugated molecules and the appropriate aromaticity descriptors to identify the part of the molecule responsible for the loss of aromaticity.
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Affiliation(s)
- Irene Casademont‐Reig
- Donostia International Physics Center (DIPC)20018DonostiaEuskadiSpain
- Polimero eta Material Aurreratuak: Fisika, Kimika eta TeknologiaKimika Fakultatea, Euskal Herriko Unibertsitatea UPV/EHUP.K. 107220080DonostiaEuskadiSpain
| | - Raúl Guerrero‐Avilés
- Donostia International Physics Center (DIPC)20018DonostiaEuskadiSpain
- Centro de Física de MaterialesCFM-MPC CSIC-UPV/EHU20018DonostiaEuskadiSpain
| | - Eloy Ramos‐Cordoba
- Donostia International Physics Center (DIPC)20018DonostiaEuskadiSpain
- Polimero eta Material Aurreratuak: Fisika, Kimika eta TeknologiaKimika Fakultatea, Euskal Herriko Unibertsitatea UPV/EHUP.K. 107220080DonostiaEuskadiSpain
| | - Miquel Torrent‐Sucarrat
- Donostia International Physics Center (DIPC)20018DonostiaEuskadiSpain
- Ikerbasque, Basque Foundation for SciencePlaza Euskadi 548009BilbaoEuskadiSpain
- Department of Organic Chemistry IUniversidad del Pais Vasco/Euskal Herriko Unibertsitatea (UPV/EHU)20018DonostiaEuskadiSpain
| | - Eduard Matito
- Donostia International Physics Center (DIPC)20018DonostiaEuskadiSpain
- Ikerbasque, Basque Foundation for SciencePlaza Euskadi 548009BilbaoEuskadiSpain
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22
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Casademont‐Reig I, Guerrero‐Avilés R, Ramos‐Cordoba E, Torrent‐Sucarrat M, Matito E. How Aromatic Are Molecular Nanorings? The Case of a Six‐Porphyrin Nanoring**. Angew Chem Int Ed Engl 2021. [DOI: 10.1002/ange.202108997] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
Affiliation(s)
- Irene Casademont‐Reig
- Donostia International Physics Center (DIPC) 20018 Donostia Euskadi Spain
- Polimero eta Material Aurreratuak: Fisika, Kimika eta Teknologia Kimika Fakultatea, Euskal Herriko Unibertsitatea UPV/EHU P.K. 1072 20080 Donostia Euskadi Spain
| | - Raúl Guerrero‐Avilés
- Donostia International Physics Center (DIPC) 20018 Donostia Euskadi Spain
- Centro de Física de Materiales CFM-MPC CSIC-UPV/EHU 20018 Donostia Euskadi Spain
| | - Eloy Ramos‐Cordoba
- Donostia International Physics Center (DIPC) 20018 Donostia Euskadi Spain
- Polimero eta Material Aurreratuak: Fisika, Kimika eta Teknologia Kimika Fakultatea, Euskal Herriko Unibertsitatea UPV/EHU P.K. 1072 20080 Donostia Euskadi Spain
| | - Miquel Torrent‐Sucarrat
- Donostia International Physics Center (DIPC) 20018 Donostia Euskadi Spain
- Ikerbasque, Basque Foundation for Science Plaza Euskadi 5 48009 Bilbao Euskadi Spain
- Department of Organic Chemistry I Universidad del Pais Vasco/Euskal Herriko Unibertsitatea (UPV/EHU) 20018 Donostia Euskadi Spain
| | - Eduard Matito
- Donostia International Physics Center (DIPC) 20018 Donostia Euskadi Spain
- Ikerbasque, Basque Foundation for Science Plaza Euskadi 5 48009 Bilbao Euskadi Spain
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23
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Amiri N, Ben Taheur F, Chevreux S, Rodrigues CM, Dorcet V, Lemercier G, Nasri H. Syntheses, crystal structures, photo-physical properties, antioxidant and antifungal activities of Mg(II) 4,4′-bipyridine and Mg(II) pyrazine complexes of the 5,10,15,20 tetrakis(4–bromophenyl)porphyrin. Inorganica Chim Acta 2021. [DOI: 10.1016/j.ica.2021.120466] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
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24
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Thomas JO, Sowa JK, Limburg B, Bian X, Evangeli C, Swett JL, Tewari S, Baugh J, Schatz GC, Briggs GAD, Anderson HL, Mol JA. Charge transport through extended molecular wires with strongly correlated electrons. Chem Sci 2021; 12:11121-11129. [PMID: 34522309 PMCID: PMC8386642 DOI: 10.1039/d1sc03050g] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/06/2021] [Accepted: 07/19/2021] [Indexed: 11/21/2022] Open
Abstract
Electron–electron interactions are at the heart of chemistry and understanding how to control them is crucial for the development of molecular-scale electronic devices. Here, we investigate single-electron tunneling through a redox-active edge-fused porphyrin trimer and demonstrate that its transport behavior is well described by the Hubbard dimer model, providing insights into the role of electron–electron interactions in charge transport. In particular, we empirically determine the molecule's on-site and inter-site electron–electron repulsion energies, which are in good agreement with density functional calculations, and establish the molecular electronic structure within various oxidation states. The gate-dependent rectification behavior confirms the selection rules and state degeneracies deduced from the Hubbard model. We demonstrate that current flow through the molecule is governed by a non-trivial set of vibrationally coupled electronic transitions between various many-body ground and excited states, and experimentally confirm the importance of electron–electron interactions in single-molecule devices. Experimental studies of electron transport through an edge-fused porphyrin oligomer in a graphene junction are interpreted within a Hubbard dimer framework.![]()
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Affiliation(s)
- James O Thomas
- Department of Materials, University of Oxford Parks Road Oxford OX1 3PH UK .,Department of Chemistry, University of Oxford, Chemistry Research Laboratory Oxford OX1 3TA UK
| | - Jakub K Sowa
- Department of Chemistry, Northwestern University Evanston Illinois 60208 USA.,Department of Chemistry, Rice University Houston TX USA
| | - Bart Limburg
- Department of Materials, University of Oxford Parks Road Oxford OX1 3PH UK .,Department of Chemistry, University of Oxford, Chemistry Research Laboratory Oxford OX1 3TA UK
| | - Xinya Bian
- Department of Materials, University of Oxford Parks Road Oxford OX1 3PH UK
| | | | - Jacob L Swett
- Department of Materials, University of Oxford Parks Road Oxford OX1 3PH UK
| | - Sumit Tewari
- Department of Materials, University of Oxford Parks Road Oxford OX1 3PH UK
| | - Jonathan Baugh
- Institute for Quantum Computing, University of Waterloo Waterloo ON N2L 3G1 Canada
| | - George C Schatz
- Department of Chemistry, Northwestern University Evanston Illinois 60208 USA
| | - G Andrew D Briggs
- Department of Materials, University of Oxford Parks Road Oxford OX1 3PH UK
| | - Harry L Anderson
- Department of Chemistry, University of Oxford, Chemistry Research Laboratory Oxford OX1 3TA UK
| | - Jan A Mol
- School of Physics and Astronomy, Queen Mary University of London London E1 4NS UK
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25
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Zhang X, Shi H, Zhuang G, Wang S, Wang J, Yang S, Shao X, Du P. A Highly Strained All‐Phenylene Conjoined Bismacrocycle. Angew Chem Int Ed Engl 2021. [DOI: 10.1002/ange.202104669] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Affiliation(s)
- Xinyu Zhang
- Hefei National Laboratory for Physical Sciences at Microscale CAS Key Laboratory of Materials for Energy Conversion Department of Materials Science and Engineering,iChEM University of Science and Technology of China Hefei Anhui Province 230026 China
| | - Hong Shi
- Department of Chemical Physics CAS Key Laboratory of Urban Pollutant Conversion Synergetic Innovation Center of Quantum Information and Quantum Physics University of Science and Technology of China Hefei Anhui Province 230026 China
| | - Guilin Zhuang
- College of Chemical Engineering Zhejiang University of Technology 18 Chaowang Road Hangzhou Zhejiang Province 310032 China
| | - Shengda Wang
- Hefei National Laboratory for Physical Sciences at Microscale CAS Key Laboratory of Materials for Energy Conversion Department of Materials Science and Engineering,iChEM University of Science and Technology of China Hefei Anhui Province 230026 China
| | - Jinyi Wang
- Hefei National Laboratory for Physical Sciences at Microscale CAS Key Laboratory of Materials for Energy Conversion Department of Materials Science and Engineering,iChEM University of Science and Technology of China Hefei Anhui Province 230026 China
| | - Shangfeng Yang
- Hefei National Laboratory for Physical Sciences at Microscale CAS Key Laboratory of Materials for Energy Conversion Department of Materials Science and Engineering,iChEM University of Science and Technology of China Hefei Anhui Province 230026 China
| | - Xiang Shao
- Department of Chemical Physics CAS Key Laboratory of Urban Pollutant Conversion Synergetic Innovation Center of Quantum Information and Quantum Physics University of Science and Technology of China Hefei Anhui Province 230026 China
| | - Pingwu Du
- Hefei National Laboratory for Physical Sciences at Microscale CAS Key Laboratory of Materials for Energy Conversion Department of Materials Science and Engineering,iChEM University of Science and Technology of China Hefei Anhui Province 230026 China
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26
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Zhang X, Shi H, Zhuang G, Wang S, Wang J, Yang S, Shao X, Du P. A Highly Strained All-Phenylene Conjoined Bismacrocycle. Angew Chem Int Ed Engl 2021; 60:17368-17372. [PMID: 33945657 DOI: 10.1002/anie.202104669] [Citation(s) in RCA: 22] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/05/2021] [Revised: 05/04/2021] [Indexed: 11/10/2022]
Abstract
Herein, we report the precise synthesis of a 3D highly strained all-phenylene bismacrocycle, termed conjoined (1,4)[10]cycloparaphenylenophane (SCPP[10]). This structure consists of a twisted benzene ring which is bridged twice by phenylene units anchored in two para-positions. The conjoined structure of SCPP[10] was confirmed in real space at the atomic scale by scanning tunneling microscopy. Theoretical calculations indicate that this bismacrocycle has a very high strain energy of 110.59 kcal mol-1 and the largest interphenylene torsion angle of 46.07° caused by multiple repulsive interactions. Furthermore, a 1:2 host-guest complex of SCPP[10] and [6,6]-phenyl-C61 -butyric acid methyl ester was investigated, which represents the first peanut-shaped 1:2 host-guest complex based on bismacrocycles.
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Affiliation(s)
- Xinyu Zhang
- Hefei National Laboratory for Physical Sciences at Microscale, CAS Key Laboratory of Materials for Energy Conversion, Department of Materials Science and Engineering,iChEM, University of Science and Technology of China, Hefei, Anhui Province, 230026, China
| | - Hong Shi
- Department of Chemical Physics, CAS Key Laboratory of Urban Pollutant Conversion, Synergetic Innovation Center of Quantum Information and Quantum Physics, University of Science and Technology of China, Hefei, Anhui Province, 230026, China
| | - Guilin Zhuang
- College of Chemical Engineering, Zhejiang University of Technology, 18 Chaowang Road, Hangzhou, Zhejiang Province, 310032, China
| | - Shengda Wang
- Hefei National Laboratory for Physical Sciences at Microscale, CAS Key Laboratory of Materials for Energy Conversion, Department of Materials Science and Engineering,iChEM, University of Science and Technology of China, Hefei, Anhui Province, 230026, China
| | - Jinyi Wang
- Hefei National Laboratory for Physical Sciences at Microscale, CAS Key Laboratory of Materials for Energy Conversion, Department of Materials Science and Engineering,iChEM, University of Science and Technology of China, Hefei, Anhui Province, 230026, China
| | - Shangfeng Yang
- Hefei National Laboratory for Physical Sciences at Microscale, CAS Key Laboratory of Materials for Energy Conversion, Department of Materials Science and Engineering,iChEM, University of Science and Technology of China, Hefei, Anhui Province, 230026, China
| | - Xiang Shao
- Department of Chemical Physics, CAS Key Laboratory of Urban Pollutant Conversion, Synergetic Innovation Center of Quantum Information and Quantum Physics, University of Science and Technology of China, Hefei, Anhui Province, 230026, China
| | - Pingwu Du
- Hefei National Laboratory for Physical Sciences at Microscale, CAS Key Laboratory of Materials for Energy Conversion, Department of Materials Science and Engineering,iChEM, University of Science and Technology of China, Hefei, Anhui Province, 230026, China
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27
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Redman A, Moise G, Richert S, Viere EJ, Myers WK, Therien MJ, Timmel CR. EPR of Photoexcited Triplet-State Acceptor Porphyrins. THE JOURNAL OF PHYSICAL CHEMISTRY. C, NANOMATERIALS AND INTERFACES 2021; 125:11782-11790. [PMID: 34276860 PMCID: PMC8279703 DOI: 10.1021/acs.jpcc.1c03278] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/12/2021] [Revised: 05/02/2021] [Indexed: 05/20/2023]
Abstract
The photoexcited triplet states of porphyrin architectures are of significant interest in a wide range of fields including molecular wires, nonlinear optics, and molecular spintronics. Electron paramagnetic resonance (EPR) is a key spectroscopic tool in the characterization of these transient paramagnetic states singularly well suited to quantify spin delocalization. Previous work proposed a means of extracting the absolute signs of the zero-field splitting (ZFS) parameters, D and E, and triplet sublevel populations by transient continuous wave, hyperfine measurements, and magnetophotoselection. Here, we present challenges of this methodology for a series of meso-perfluoroalkyl-substituted zinc porphyrin monomers with orthorhombic symmetries, where interpretation of experimental data must proceed with caution and the validity of the assumptions used in the analysis must be scrutinized. The EPR data are discussed alongside quantum chemical calculations, employing both DFT and CASSCF methodologies. Despite some success of the latter in quantifying the magnitude of the ZFS interaction, the results clearly provide motivation to develop improved methods for ZFS calculations of highly delocalized organic triplet states.
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Affiliation(s)
- Ashley
J. Redman
- Centre
for Advanced Electron Spin Resonance (CÆSR), University of Oxford, South Parks Road, Oxford OX1 3QR, United Kingdom
| | - Gabriel Moise
- Centre
for Advanced Electron Spin Resonance (CÆSR), University of Oxford, South Parks Road, Oxford OX1 3QR, United Kingdom
| | - Sabine Richert
- Institute
of Physical Chemistry, University of Freiburg, Albertstraße 21, 79104 Freiburg, Germany
| | - Erin J. Viere
- Department
of Chemistry, Duke University, French Family
Science Center, 124 Science Drive, Durham, North Carolina 27708, United States
| | - William K. Myers
- Centre
for Advanced Electron Spin Resonance (CÆSR), University of Oxford, South Parks Road, Oxford OX1 3QR, United Kingdom
| | - Michael J. Therien
- Department
of Chemistry, Duke University, French Family
Science Center, 124 Science Drive, Durham, North Carolina 27708, United States
| | - Christiane R. Timmel
- Centre
for Advanced Electron Spin Resonance (CÆSR), University of Oxford, South Parks Road, Oxford OX1 3QR, United Kingdom
- . Phone: +44 (0)1865 272682
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28
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Pribitzer S, Mannikko D, Stoll S. Determining electron-nucleus distances and Fermi contact couplings from ENDOR spectra. Phys Chem Chem Phys 2021; 23:8326-8335. [PMID: 33875997 DOI: 10.1039/d1cp00229e] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Abstract
The hyperfine coupling between an electron spin and a nuclear spin depends on the Fermi contact coupling aiso and, through dipolar coupling, the distance r between the electron and the nucleus. It is measured with electron-nuclear double resonance (ENDOR) spectroscopy and provides insight into the electronic and spatial structure of paramagnetic centers. The analysis and interpretation of ENDOR spectra is commonly done by ordinary least-squares fitting. As this is an ill-posed, inverse mathematical problem, this is challenging, in particular for spectra that show features from several nuclei or where the hyperfine coupling parameters are distributed. We introduce a novel Tikhonov-type regularization approach that analyzes an experimental ENDOR spectrum in terms of a complete non-parametric distribution over r and aiso. The approach uses a penalty function similar to the cross entropy between the fitted distribution and a Bayesian prior distribution that is derived from density functional theory calculations. Additionally, we show that smoothness regularization, commonly used for a similar purpose in double electron-electron resonance (DEER) spectroscopy, is not suited for ENDOR. We demonstrate that the novel approach is able to identify and quantitate ligand protons with electron-nucleus distances between 4 and 9 Å in a series of vanadyl porphyrin compounds.
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Affiliation(s)
- Stephan Pribitzer
- Department of Chemistry, University of Washington, Seattle, WA 98195, USA.
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29
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Taylor JO, Pižl M, Kloz M, Rebarz M, McCusker CE, McCusker JK, Záliš S, Hartl F, Vlček A. Optical and Infrared Spectroelectrochemical Studies of CN-Substituted Bipyridyl Complexes of Ruthenium(II). Inorg Chem 2021; 60:3514-3523. [PMID: 33645219 DOI: 10.1021/acs.inorgchem.0c03579] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Ruthenium(II) polypyridyl complexes [Ru(CN-Me-bpy)x(bpy)3-x]2+ (CN-Me-bpy = 4,4'-dicyano-5,5'-dimethyl-2,2'-bipyridine, bpy = 2,2'-bipyridine, and x = 1-3, abbreviated as 12+, 22+, and 32+) undergo four (12+) or five (22+ and 32+) successive one-electron reduction steps between -1.3 and -2.75 V versus ferrocenium/ferrocene (Fc+/Fc) in tetrahydrofuran. The CN-Me-bpy ligands are reduced first, with successive one-electron reductions in 22+ and 32+ being separated by 150-210 mV; reduction of the unsubstituted bpy ligand in 12+ and 22+ occurs only when all CN-Me-bpy ligands have been converted to their radical anions. Absorption spectra of the first three reduction products of each complex were measured across the UV, visible, near-IR (NIR), and mid-IR regions and interpreted with the help of density functional theory calculations. Reduction of the CN-Me-bpy ligand shifts the ν(C≡N) IR band by ca. -45 cm-1, enhances its intensity ∼35 times, and splits the symmetrical and antisymmetrical modes. Semireduced complexes containing two and three CN-derivatized ligands 2+, 3+, and 30 show distinct ν(C≡N) features due to the presence of both CN-Me-bpy and CN-Me-bpy•-, confirming that each reduction is localized on a single ligand. NIR spectra of 10, 1-, and 2- exhibit a prominent band attributable to the CN-Me-bpy•- moiety between 6000 and 7500 cm-1, whereas bpy•--based absorption occurs between 4500 and 6000 cm-1; complexes 2+, 3+, and 30 also exhibit a band at ca. 3300 cm-1 due to a CN-Me-bpy•- → CN-Me-bpy interligand charge-transfer transition. In the UV-vis region, the decrease of π → π* intraligand bands of the neutral ligands and the emergence of the corresponding bands of the radical anions are most diagnostic. The first reduction product of 12+ is spectroscopically similar to the lowest triplet metal-to-ligand charge-transfer excited state, which shows pronounced NIR absorption, and its ν(C≡N) IR band is shifted by -38 cm-1 and 5-7-fold-enhanced relative to the ground state.
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Affiliation(s)
- James O Taylor
- Department of Chemistry, University of Reading, Whiteknights Park, Reading RG6 6DX, United Kingdom
| | - Martin Pižl
- J. Heyrovský Institute of Physical Chemistry, Academy of Sciences of the Czech Republic, Dolejškova 3, CZ-18223 Prague, Czech Republic.,Department of Inorganic Chemistry, University of Chemistry and Technology, Prague, CZ-16628 Prague, Czech Republic
| | - Miroslav Kloz
- ELI Beamlines, Institute of Physics, Czech Academy of Sciences, CZ-18200 Prague, Czech Republic
| | - Mateusz Rebarz
- ELI Beamlines, Institute of Physics, Czech Academy of Sciences, CZ-18200 Prague, Czech Republic
| | - Catherine E McCusker
- Department of Chemistry, Michigan State University, East Lansing, Michigan 48824, United States
| | - James K McCusker
- Department of Chemistry, Michigan State University, East Lansing, Michigan 48824, United States
| | - Stanislav Záliš
- J. Heyrovský Institute of Physical Chemistry, Academy of Sciences of the Czech Republic, Dolejškova 3, CZ-18223 Prague, Czech Republic
| | - František Hartl
- Department of Chemistry, University of Reading, Whiteknights Park, Reading RG6 6DX, United Kingdom
| | - Antonín Vlček
- School of Biological and Chemical Sciences, Queen Mary University of London, Mile End Road, E1 4NS London, United Kingdom.,J. Heyrovský Institute of Physical Chemistry, Academy of Sciences of the Czech Republic, Dolejškova 3, CZ-18223 Prague, Czech Republic
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30
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Jirásek M, Rickhaus M, Tejerina L, Anderson HL. Experimental and Theoretical Evidence for Aromatic Stabilization Energy in Large Macrocycles. J Am Chem Soc 2021; 143:2403-2412. [PMID: 33497211 DOI: 10.1021/jacs.0c12845] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
Enhanced thermodynamic stability is a fundamental characteristic of aromatic molecules, yet most previous studies of aromatic stabilization energy (ASE) have been limited to small rings with up to 18 π-electrons. Here we demonstrate that ASE can be detected experimentally in π-conjugated porphyrin nanorings with Hückel circuits of 76-108 π-electrons. This conclusion is supported by analyzing redox potentials to calculate the energy change for isodesmic reactions that convert an aromatic ring to an antiaromatic ring or vice versa. It is also supported by analyzing the energy barriers to conformational equilibria that disrupt aromaticity in the transition state. Both types of experiment indicate that cationic porphyrin nanorings display ASEs of 1-5 kJ mol-1. Density functional theory calculations reproduce the results for both types of experiment and predict ASEs in the range of 1-16 kJ mol-1. The experimental ASEs in porphyrin nanorings are compared with an experimental ASE of [18]annulene of ∼11 kJ mol-1, deduced from analysis of the energy barriers to conformational equilibria in [16], [18], and [20]annulene. Calculated energies of isodesmic reactions give an ASE of ∼37 kJ mol-1 in [18]annulene. This work contributes to a fundamental understanding of aromaticity in large macrocycles.
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Affiliation(s)
- Michael Jirásek
- Department of Chemistry, Chemistry Research Laboratory, University of Oxford, Oxford OX1 3TA, U.K
| | - Michel Rickhaus
- Department of Chemistry, Chemistry Research Laboratory, University of Oxford, Oxford OX1 3TA, U.K
| | - Lara Tejerina
- Department of Chemistry, Chemistry Research Laboratory, University of Oxford, Oxford OX1 3TA, U.K
| | - Harry L Anderson
- Department of Chemistry, Chemistry Research Laboratory, University of Oxford, Oxford OX1 3TA, U.K
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31
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Ayub R, El Bakouri O, Smith JR, Jorner K, Ottosson H. Triplet State Baird Aromaticity in Macrocycles: Scope, Limitations, and Complications. J Phys Chem A 2021; 125:570-584. [PMID: 33427474 PMCID: PMC7884009 DOI: 10.1021/acs.jpca.0c08926] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2020] [Revised: 12/18/2020] [Indexed: 02/06/2023]
Abstract
The aromaticity of cyclic 4nπ-electron molecules in their first ππ* triplet state (T1), labeled Baird aromaticity, has gained growing attention in the past decade. Here we explore computationally the limitations of T1 state Baird aromaticity in macrocyclic compounds, [n]CM's, which are cyclic oligomers of four different monocycles (M = p-phenylene (PP), 2,5-linked furan (FU), 1,4-linked cyclohexa-1,3-diene (CHD), and 1,4-linked cyclopentadiene (CPD)). We strive for conclusions that are general for various DFT functionals, although for macrocycles with up to 20 π-electrons in their main conjugation paths we find that for their T1 states single-point energies at both canonical UCCSD(T) and approximative DLPNO-UCCSD(T) levels are lowest when based on UB3LYP over UM06-2X and UCAM-B3LYP geometries. This finding is in contrast to what has earlier been observed for the electronic ground state of expanded porphyrins. Yet, irrespective of functional, macrocycles with 2,5-linked furans ([n]CFU's) retain Baird aromaticity until larger n than those composed of the other three monocycles. Also, when based on geometric, electronic and energetic aspects of aromaticity, a 3[n]CFU with a specific n is more strongly Baird-aromatic than the analogous 3[n]CPP while the magnetic indices tell the opposite. To construct large T1 state Baird-aromatic [n]CM's, the design should be such that the T1 state Baird aromaticity of the macrocyclic perimeter dominates over a situation with local closed-shell Hückel aromaticity of one or a few monocycles and semilocalized triplet diradical character. Monomers with lower Hückel aromaticity in S0 than benzene (e.g., furan) that do not impose steric congestion are preferred. Structural confinement imposed by, e.g., methylene bridges is also an approach to larger Baird-aromatic macrocycles. Finally, by using the Zilberg-Haas description of T1 state aromaticity, we reveal the analogy to the Hückel aromaticity of the corresponding closed-shell dications yet observe stronger Hückel aromaticity in the macrocyclic dications than Baird aromaticity in the T1 states of the neutral macrocycles.
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Affiliation(s)
- Rabia Ayub
- Department
of Chemistry - Ångström Laboratory, Uppsala University, Box 523, SE-751 20, Uppsala, Sweden
| | - Ouissam El Bakouri
- Department
of Chemistry - Ångström Laboratory, Uppsala University, Box 523, SE-751 20, Uppsala, Sweden
| | - Joshua R. Smith
- Department
of Chemistry - Ångström Laboratory, Uppsala University, Box 523, SE-751 20, Uppsala, Sweden
- Department
of Chemistry, Humboldt State University, One Harpst Street, Arcata, California 95521, United States
| | - Kjell Jorner
- Department
of Chemistry - Ångström Laboratory, Uppsala University, Box 523, SE-751 20, Uppsala, Sweden
| | - Henrik Ottosson
- Department
of Chemistry - Ångström Laboratory, Uppsala University, Box 523, SE-751 20, Uppsala, Sweden
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32
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Garrido-Barros P, Moonshiram D, Gil-Sepulcre M, Pelosin P, Gimbert-Suriñach C, Benet-Buchholz J, Llobet A. Redox Metal-Ligand Cooperativity Enables Robust and Efficient Water Oxidation Catalysis at Neutral pH with Macrocyclic Copper Complexes. J Am Chem Soc 2020; 142:17434-17446. [PMID: 32935982 DOI: 10.1021/jacs.0c06515] [Citation(s) in RCA: 40] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
Abstract
Water oxidation catalysis stands out as one of the most important reactions to design practical devices for artificial photosynthesis. Use of late first-row transition metal (TM) complexes provides an excellent platform for the development of inexpensive catalysts with exquisite control on their electronic and structural features via ligand design. However, the difficult access to their high oxidation states and the general labile character of their metal-ligand bonds pose important challenges. Herein, we explore a copper complex (12-) featuring an extended, π-delocalized, tetra-amidate macrocyclic ligand (TAML) as water oxidation catalyst and compare its activity to analogous systems with lower π-delocalization (22- and 32-). Their characterization evidences a special metal-ligand cooperativity in accommodating the required oxidative equivalents using 12- that is absent in 22- and 32-. This consists of charge delocalization promoted by easy access to different electronic states at a narrow energy range, corresponding to either metal-centered or ligand-centered oxidations, which we identify as an essential factor to stabilize the accumulated oxidative charges. This translates into a significant improvement in the catalytic performance of 12- compared to 22- and 32- and leads to one of the most active and robust molecular complexes for water oxidation at neutral pH with a kobs of 140 s-1 at an overpotential of only 200 mV. In contrast, 22- degrades under oxidative conditions, which we associate to the impossibility of efficiently stabilizing several oxidative equivalents via charge delocalization, resulting in a highly reactive oxidized ligand. Finally, the acyclic structure of 32- prevents its use at neutral pH due to acidic demetalation, highlighting the importance of the macrocyclic stabilization.
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Affiliation(s)
- Pablo Garrido-Barros
- Institute of Chemical Research of Catalonia (ICIQ), Barcelona Institute of Science and Technology (BIST), Avinguda Països Catalans, 16, 43007 Tarragona, Spain
| | - Dooshaye Moonshiram
- Instituto Madrileño de Estudios Avanzados en Nanociencia (IMDE A Nanociencia), Calle Faraday, 9, 28049 Madrid, Spain
| | - Marcos Gil-Sepulcre
- Institute of Chemical Research of Catalonia (ICIQ), Barcelona Institute of Science and Technology (BIST), Avinguda Països Catalans, 16, 43007 Tarragona, Spain
| | - Primavera Pelosin
- Institute of Chemical Research of Catalonia (ICIQ), Barcelona Institute of Science and Technology (BIST), Avinguda Països Catalans, 16, 43007 Tarragona, Spain
| | - Carolina Gimbert-Suriñach
- Institute of Chemical Research of Catalonia (ICIQ), Barcelona Institute of Science and Technology (BIST), Avinguda Països Catalans, 16, 43007 Tarragona, Spain
| | - Jordi Benet-Buchholz
- Institute of Chemical Research of Catalonia (ICIQ), Barcelona Institute of Science and Technology (BIST), Avinguda Països Catalans, 16, 43007 Tarragona, Spain
| | - Antoni Llobet
- Institute of Chemical Research of Catalonia (ICIQ), Barcelona Institute of Science and Technology (BIST), Avinguda Països Catalans, 16, 43007 Tarragona, Spain.,Departament de Química, Universitat Autònoma de Barcelona, 08193 Bellaterra, Spain
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33
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Ziogos OG, Blanco I, Blumberger J. Ultrathin porphyrin and tetra-indole covalent organic frameworks for organic electronics applications. J Chem Phys 2020; 153:044702. [PMID: 32752720 DOI: 10.1063/5.0010164] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
The electronic and charge transport properties of porphyrin and tetra-indole porphyrinoid single layer covalent organic frameworks (COFs) are investigated by means of density functional theory calculations. Ultrathin diacetylene-linked COFs based on oxidized tetra-indole cores are narrow gap 2D semiconductors, featuring a pronounced anisotropic electronic band structure due to the combination of dispersive and flat band characteristics, while registering high room temperature charge carrier mobilities. The capability of bandgap and charge carrier localization tuning via the careful selection of fourfold porphyrin and porphyrinoid cores and twofold articulated linkers is demonstrated, with the majority of systems exhibiting electronic gap values between 1.75 eV and 2.3 eV. Tetra-indoles are also capable of forming stable monolayers via non-articulated core fusing, resulting in 2D morphologies with extended π-conjugation and semi-metallic behavior.
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Affiliation(s)
- Orestis George Ziogos
- Department of Physics and Astronomy, University College London, Gower Street, London WC1E 6BT, United Kingdom
| | - Itsaso Blanco
- Department of Physics and Astronomy, University College London, Gower Street, London WC1E 6BT, United Kingdom
| | - Jochen Blumberger
- Department of Physics and Astronomy, University College London, Gower Street, London WC1E 6BT, United Kingdom
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34
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Nançoz C, Rumble C, Rosspeintner A, Vauthey E. Bimolecular photoinduced electron transfer in non-polar solvents beyond the diffusion limit. J Chem Phys 2020; 152:244501. [PMID: 32610996 DOI: 10.1063/5.0012363] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022] Open
Abstract
Electron transfer (ET) quenching dynamics in non-polar solvents are investigated using ultrafast spectroscopy with a series of six fluorophore/quencher pairs, covering a driving force range of more than 1.3 eV. The intrinsic ET rate constants, k0, deduced from the quenching dynamics in the static regime, are of the order of 1012-1013 M-1 s-1, i.e., at least as large as in acetonitrile, and do not exhibit any marked dependence on the driving force. A combination of transient electronic and vibrational absorption spectroscopy measurements reveals that the primary product of static quenching is a strongly coupled exciplex that decays within a few picoseconds. More weakly coupled exciplexes with a longer lifetime are generated subsequently, during the dynamic, diffusion-controlled, stage of the quenching. The results suggest that static ET quenching in non-polar solvents should be viewed as an internal conversion from a locally excited state to a charge-transfer state of a supermolecule rather than as a non-adiabatic ET process.
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Affiliation(s)
- Christoph Nançoz
- Department of Physical Chemistry, University of Geneva, 30 Quai Ernest-Ansermet, CH-1211 Geneva, Switzerland
| | - Christopher Rumble
- Department of Physical Chemistry, University of Geneva, 30 Quai Ernest-Ansermet, CH-1211 Geneva, Switzerland
| | - Arnulf Rosspeintner
- Department of Physical Chemistry, University of Geneva, 30 Quai Ernest-Ansermet, CH-1211 Geneva, Switzerland
| | - Eric Vauthey
- Department of Physical Chemistry, University of Geneva, 30 Quai Ernest-Ansermet, CH-1211 Geneva, Switzerland
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Wolf M, Lungerich D, Bauroth S, Popp M, Platzer B, Clark T, Anderson HL, Jux N, Guldi DM. Panchromatic light funneling through the synergy in hexabenzocoronene-(metallo)porphyrin-fullerene assemblies to realize the separation of charges. Chem Sci 2020; 11:7123-7132. [PMID: 34122999 PMCID: PMC8159381 DOI: 10.1039/d0sc02028a] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/09/2020] [Accepted: 06/16/2020] [Indexed: 11/25/2022] Open
Abstract
Here, we present a novel butadiyne-linked HBC-ethynyl-porphyrin dimer, which exhibits in the ground state strong absorption cross sections throughout the UV and visible ranges of the solar spectrum. In short, a unidirectional flow of excited state energy from the HBC termini to the (metallo)porphyrin focal points enables concentrating light at the latter. Control over excitonic interactions within, for example, the electron-donating porphyrin dimers was realized by complexation of bidentate ligands to set up panchromatic absorption that extends all the way into the near-infrared range. The bidentate binding motif was then exploited to create a supramolecular electron donor-acceptor assembly based on a HBC-ethynyl-porphyrin dimer and an electron accepting bis(aminoalkyl)-substituted fullerene. Of great relevance is the fact that charge separation from the photoexcited HBC-ethynyl-porphyrin dimer to the bis(aminoalkyl)-substituted fullerene is activated not only upon photoexciting the HBCs in the UV as well as the (metallo)porphyrins in the visible but also in the NIR. Implicit is the synergetic interplay of energy and charge transfer in a photosynthetic mimicking manner. The dimer and bis-HBC-ethynyl-porphyrin monomers, which serve as references, were probed by means of steady-state as well as time-resolved optical spectroscopies, including global target analyses of the time-resolved transient absorption data.
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Affiliation(s)
- Maximilian Wolf
- Department of Chemistry and Pharmacy, Friedrich-Alexander-University Erlangen-Nuremberg, Interdisciplinary Center for Molecular Materials (ICMM) Egerlandstraße 3 91058 Erlangen Germany
| | - Dominik Lungerich
- Department of Chemistry and Pharmacy, Friedrich-Alexander-University Erlangen-Nuremberg, Interdisciplinary Center for Molecular Materials (ICMM) Nikolaus-Fiebiger-Str. 10 91058 Erlangen Germany
- Department of Chemistry, University of Oxford, Chemistry Research Laboratory Oxford OX1 3TA UK
| | - Stefan Bauroth
- Department of Chemistry and Pharmacy, Friedrich-Alexander-University Erlangen-Nuremberg, Interdisciplinary Center for Molecular Materials (ICMM) Egerlandstraße 3 91058 Erlangen Germany
- Department of Chemistry and Pharmacy, Computer Chemistry Centre (CCC), Friedrich-Alexander-University Germany
| | - Maximilian Popp
- Department of Chemistry and Pharmacy, Friedrich-Alexander-University Erlangen-Nuremberg, Interdisciplinary Center for Molecular Materials (ICMM) Nikolaus-Fiebiger-Str. 10 91058 Erlangen Germany
| | - Benedikt Platzer
- Department of Chemistry and Pharmacy, Friedrich-Alexander-University Erlangen-Nuremberg, Interdisciplinary Center for Molecular Materials (ICMM) Egerlandstraße 3 91058 Erlangen Germany
| | - Timothy Clark
- Department of Chemistry and Pharmacy, Computer Chemistry Centre (CCC), Friedrich-Alexander-University Germany
| | - Harry L Anderson
- Department of Chemistry, University of Oxford, Chemistry Research Laboratory Oxford OX1 3TA UK
| | - Norbert Jux
- Department of Chemistry and Pharmacy, Friedrich-Alexander-University Erlangen-Nuremberg, Interdisciplinary Center for Molecular Materials (ICMM) Nikolaus-Fiebiger-Str. 10 91058 Erlangen Germany
| | - Dirk M Guldi
- Department of Chemistry and Pharmacy, Friedrich-Alexander-University Erlangen-Nuremberg, Interdisciplinary Center for Molecular Materials (ICMM) Egerlandstraße 3 91058 Erlangen Germany
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Dereka B, Svechkarev D, Rosspeintner A, Aster A, Lunzer M, Liska R, Mohs AM, Vauthey E. Solvent tuning of photochemistry upon excited-state symmetry breaking. Nat Commun 2020; 11:1925. [PMID: 32317631 PMCID: PMC7174366 DOI: 10.1038/s41467-020-15681-3] [Citation(s) in RCA: 41] [Impact Index Per Article: 10.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/09/2020] [Accepted: 03/20/2020] [Indexed: 12/29/2022] Open
Abstract
The nature of the electronic excited state of many symmetric multibranched donor–acceptor molecules varies from delocalized/multipolar to localized/dipolar depending on the environment. Solvent-driven localization breaks the symmetry and traps the exciton in one branch. Using a combination of ultrafast spectroscopies, we investigate how such excited-state symmetry breaking affects the photochemical reactivity of quadrupolar and octupolar A–(π-D)2,3 molecules with photoisomerizable A–π–D branches. Excited-state symmetry breaking is identified by monitoring several spectroscopic signatures of the multipolar delocalized exciton, including the S2 ← S1 electronic transition, whose energy reflects interbranch coupling. It occurs in all but nonpolar solvents. In polar media, it is rapidly followed by an alkyne–allene isomerization of the excited branch. In nonpolar solvents, slow and reversible isomerization corresponding to chemically-driven symmetry breaking, is observed. These findings reveal that the photoreactivity of large conjugated molecules can be tuned by controlling the localization of the excitation. Symmetric multibranched donor-acceptor molecules are promising photoactive materials for diverse applications. Here the authors show that, in octupolar and quadrupolar dyes, excited-state symmetry breaking occurs efficiently in polar solvents only and results in a concentration of the excitation that may trigger fast photochemical reactions.
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Affiliation(s)
- Bogdan Dereka
- Department of Physical Chemistry, University of Geneva, 30 Quai Ernest-Ansermet, 1211, Geneva, Switzerland.,Department of Chemistry and Institute for Biophysical Dynamics, James Franck Institute, The University of Chicago, 929 E. 57th St., Chicago, IL, 60637, USA
| | - Denis Svechkarev
- Department of Pharmaceutical Sciences, University of Nebraska Medical Center, Omaha, NE, 68198-6858, USA
| | - Arnulf Rosspeintner
- Department of Physical Chemistry, University of Geneva, 30 Quai Ernest-Ansermet, 1211, Geneva, Switzerland
| | - Alexander Aster
- Department of Physical Chemistry, University of Geneva, 30 Quai Ernest-Ansermet, 1211, Geneva, Switzerland
| | - Markus Lunzer
- Institute of Applied Synthetic Chemistry, TU Wien, Getreidemarkt 9/163/MC, 1060, Vienna, Austria
| | - Robert Liska
- Institute of Applied Synthetic Chemistry, TU Wien, Getreidemarkt 9/163/MC, 1060, Vienna, Austria
| | - Aaron M Mohs
- Department of Pharmaceutical Sciences, University of Nebraska Medical Center, Omaha, NE, 68198-6858, USA.,Department of Biochemistry and Molecular Biology, Fred and Pamela Buffett Cancer Center, University of Nebraska Medical Center, Omaha, NE, 68198-6858, USA
| | - Eric Vauthey
- Department of Physical Chemistry, University of Geneva, 30 Quai Ernest-Ansermet, 1211, Geneva, Switzerland.
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Xia Y, Shuai L, Wang Y, Ma Y, Han L, Qiu M, Zhang Z, Leung MKH. Designing bifuncitonal molecular devices with a metalloporphyrin dimer. Phys Chem Chem Phys 2020; 22:4080-4085. [PMID: 32031181 DOI: 10.1039/c9cp05079e] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Abstract
Many organic molecules have unique magnetic properties and can potentially serve as excellent molecular spin devices, which is worth exploring deeply. Here, the spin transport properties of Mn, Fe, Co and Cu porphyrin dimer devices are investigated based on the first principles method. The spin filtering efficiencies of these molecular devices are maintained at 100% within certain applied voltage ranges and magnetoresistance ratios are higher than 108% which increase as the voltage increases. To explain the excellent spin-filtering and giant magnetoresistance effects, analysis of spin electron densities and transmission spectra indicates that magnetic properties are mainly contributed by the metal atoms and their neighbouring N atoms. From the transmission pathway studies, spin electrons come mainly through the π-conjugated structure of the metal porphyrin ring. Interestingly, in the Cu porphyrin dimer device, magnetic moments of the Cu-N structure in the Cu porphyrin dimer device show spin behaviors different from those of Mn, Fe and Co porphyrin dimer devices.
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Affiliation(s)
- Ying Xia
- Institute of Nanoscience and Nanotechnology, College of Physical Science and Technology, Central China Normal University, Wuhan 430079, China.
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38
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Kendrick WJ, Jirásek M, Peeks MD, Greetham GM, Sazanovich IV, Donaldson PM, Towrie M, Parker AW, Anderson HL. Mechanisms of IR amplification in radical cation polarons. Chem Sci 2020; 11:2112-2120. [PMID: 34123299 PMCID: PMC8150116 DOI: 10.1039/c9sc05717j] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/11/2019] [Accepted: 12/12/2019] [Indexed: 12/30/2022] Open
Abstract
Break down of the Born-Oppenheimer approximation is caused by mixing of electronic and vibrational transitions in the radical cations of some conjugated polymers, resulting in unusually intense vibrational bands known as infrared active vibrations (IRAVs). Here, we investigate the mechanism of this amplification, and show that it provides insights into intramolecular charge migration. Spectroelectrochemical time-resolved infrared (TRIR) and two-dimensional infrared (2D-IR) spectroscopies were used to investigate the radical cations of two butadiyne-linked conjugated porphyrin oligomers, a linear dimer and a cyclic hexamer. The 2D-IR spectra reveal strong coupling between all the IRAVs and the electronic π-π* polaron band. Intramolecular vibrational energy redistribution (IVR) and vibrational relaxation occur within ∼0.1-7 ps. TRIR spectra show that the transient ground state bleach (GSB) and excited state absorption (ESA) signals have anisotropies of 0.31 ± 0.07 and 0.08 ± 0.04 for the linear dimer and cyclic hexamer cations, respectively. The small TRIR anisotropy for the cyclic hexamer radical cation indicates that the vibrationally excited polaron migrates round the nanoring on a time scale faster than the measurement, i.e. within 0.5 ps, at 298 K. Density functional theory (DFT) calculations qualitatively reproduce the emergence of the IRAVs. The first singlet (S1) excited states of the neutral porphyrin oligomers exhibit similar IRAVs to the radical cations, implying that the excitons have similar electronic structures to polarons. Our results show that IRAVs originate from the strong coupling of charge redistribution to nuclear motion, and from the similar energies of electronic and vibrational transitions.
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Affiliation(s)
- William J Kendrick
- Department of Chemistry, University of Oxford, Chemistry Research Laboratory Oxford OX1 3TA UK
| | - Michael Jirásek
- Department of Chemistry, University of Oxford, Chemistry Research Laboratory Oxford OX1 3TA UK
| | - Martin D Peeks
- Department of Chemistry, University of Oxford, Chemistry Research Laboratory Oxford OX1 3TA UK
| | - Gregory M Greetham
- Central Laser Facility, Research Complex at Harwell, Science and Technology Facilities Council Didcot OX11 0QX UK
| | - Igor V Sazanovich
- Central Laser Facility, Research Complex at Harwell, Science and Technology Facilities Council Didcot OX11 0QX UK
| | - Paul M Donaldson
- Central Laser Facility, Research Complex at Harwell, Science and Technology Facilities Council Didcot OX11 0QX UK
| | - Michael Towrie
- Central Laser Facility, Research Complex at Harwell, Science and Technology Facilities Council Didcot OX11 0QX UK
| | - Anthony W Parker
- Central Laser Facility, Research Complex at Harwell, Science and Technology Facilities Council Didcot OX11 0QX UK
| | - Harry L Anderson
- Department of Chemistry, University of Oxford, Chemistry Research Laboratory Oxford OX1 3TA UK
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Dimitrijević MS, Bogdanović Pristov J, žiŽić M, Stanković DM, Bajuk-Bogdanović D, Stanić M, Spasić S, Hagen W, Spasojević I. Biliverdin-copper complex at physiological pH. Dalton Trans 2019; 48:6061-6070. [PMID: 30734795 DOI: 10.1039/c8dt04724c] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
Biliverdin (BV), a product of heme catabolism, is known to interact with transition metals, but the details of such interactions under physiological conditions are scarce. Herein, we examined coordinate/redox interactions of BV with Cu2+ in phosphate buffer at pH 7.4, using spectrophotometry, HESI-MS, Raman spectroscopy, 1H NMR, EPR, fluorimetry, and electrochemical methods. BV formed a stable coordination complex with copper in 1 : 1 stoichiometry. The structure of BV was more planar and energetically stable in the complex. The complex showed strong paramagnetic effects that were attributed to an unpaired delocalized e-. The delocalized electron may come from BV or Cu2+, so the complex is formally composed either of BV radical cation and Cu1+ or of BV radical anion and Cu3+. The complex underwent oxidation only in the presence of both O2 and an excess of Cu2+, or a strong oxidizing agent, and it was resistant to reducing agents. The biological effects of the stable BV metallocomplex containing a delocalized unpaired electron should be further examined, and may provide an answer to the long-standing question of high energy investment in the catabolism of BV, which represents a relatively harmless molecule per se.
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Affiliation(s)
- Milena S Dimitrijević
- Department of Life Sciences, Institute for Multidisciplinary Research, University of Belgrade, Kneza Višeslava 1, 11030 Belgrade, Serbia.
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40
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Xu Y, Gsänger S, Minameyer MB, Imaz I, Maspoch D, Shyshov O, Schwer F, Ribas X, Drewello T, Meyer B, von Delius M. Highly Strained, Radially π-Conjugated Porphyrinylene Nanohoops. J Am Chem Soc 2019; 141:18500-18507. [DOI: 10.1021/jacs.9b08584] [Citation(s) in RCA: 30] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Affiliation(s)
- Youzhi Xu
- Institute of Organic Chemistry, University of Ulm, Albert-Einstein-Allee 11, 89081 Ulm, Germany
| | - Sebastian Gsänger
- Interdisciplinary Center for Molecular Materials (ICMM) and Computer-Chemistry-Center (CCC), Friedrich-Alexander University Erlangen-Nürnberg, Nägelsbachstrasse 25, 91052 Erlangen, Germany
| | - Martin B. Minameyer
- Department of Chemistry and Pharmacy, Friedrich-Alexander University Erlangen-Nürnberg, Egerlandstrasse 3, 91058 Erlangen, Germany
| | - Inhar Imaz
- Catalan Institute of Nanoscience and Nanotechnology (ICN2), CSIC and the Barcelona Institute of Science and Technology, Campus UAB, 08193 Bellaterra, Barcelona, Catalonia, Spain
| | - Daniel Maspoch
- Catalan Institute of Nanoscience and Nanotechnology (ICN2), CSIC and the Barcelona Institute of Science and Technology, Campus UAB, 08193 Bellaterra, Barcelona, Catalonia, Spain
- ICREA, Pg. Lluís Companys 23, 08010 Barcelona, Spain
| | - Oleksandr Shyshov
- Institute of Organic Chemistry, University of Ulm, Albert-Einstein-Allee 11, 89081 Ulm, Germany
| | - Fabian Schwer
- Institute of Organic Chemistry, University of Ulm, Albert-Einstein-Allee 11, 89081 Ulm, Germany
| | - Xavi Ribas
- Institut de Química Computacional i Catàlisi and Departament de Química, Universitat de Girona, Campus Montilivi, 17003 Girona, Catalonia, Spain
| | - Thomas Drewello
- Department of Chemistry and Pharmacy, Friedrich-Alexander University Erlangen-Nürnberg, Egerlandstrasse 3, 91058 Erlangen, Germany
| | - Bernd Meyer
- Interdisciplinary Center for Molecular Materials (ICMM) and Computer-Chemistry-Center (CCC), Friedrich-Alexander University Erlangen-Nürnberg, Nägelsbachstrasse 25, 91052 Erlangen, Germany
| | - Max von Delius
- Institute of Organic Chemistry, University of Ulm, Albert-Einstein-Allee 11, 89081 Ulm, Germany
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41
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Moise G, Tejerina L, Rickhaus M, Anderson HL, Timmel CR. Spin Delocalization in the Radical Cations of Porphyrin Molecular Wires: A New Perspective on EPR Approaches. J Phys Chem Lett 2019; 10:5708-5712. [PMID: 31512868 PMCID: PMC6778911 DOI: 10.1021/acs.jpclett.9b02262] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2019] [Accepted: 08/28/2019] [Indexed: 05/29/2023]
Abstract
The spin delocalization in the radical cations of a series of ethyne-linked oligoporphyrins was investigated using EPR spectroscopy. The room-temperature spectral envelope for these oligomers deviates significantly from the benchmark N-0.5 trend in line width expected for a completely delocalized spin density, in contrast to the butadiyne-linked analogues measured previously. Here, we show, using DFT calculations and complementary low-temperature ENDOR measurements, that this deviation is primarily driven by a more pronounced inequivalence of the 14N spins within individual subunits for the ethyne-linked oligoporphyrins. Once this 14N inequivalence is taken into consideration, the room-temperature and ENDOR spectra for both butadiyne-linked and ethyne-linked oligomers, up to N = 5, can be simulated by similar static delocalization patterns. This work highlights the importance of EPR in exploring such spin delocalization phenomena while also demonstrating that the N-0.5 trend should not be interpreted in isolation but only in combination with careful simulation and theoretical modeling.
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Affiliation(s)
- Gabriel Moise
- Centre
for Advanced Electron Spin Resonance, Department of Chemistry, University of Oxford, Oxford OX1 3QR, United Kingdom
| | - Lara Tejerina
- Chemistry
Research Laboratory, Department of Chemistry, University of Oxford, Oxford OX1 3TA, United Kingdom
| | - Michel Rickhaus
- Chemistry
Research Laboratory, Department of Chemistry, University of Oxford, Oxford OX1 3TA, United Kingdom
| | - Harry L. Anderson
- Chemistry
Research Laboratory, Department of Chemistry, University of Oxford, Oxford OX1 3TA, United Kingdom
| | - Christiane R. Timmel
- Centre
for Advanced Electron Spin Resonance, Department of Chemistry, University of Oxford, Oxford OX1 3QR, United Kingdom
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42
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Arnold A, Sherbow TJ, Sayler RI, Britt RD, Thompson EJ, Muñoz MT, Fettinger JC, Berben LA. Organic Electron Delocalization Modulated by Ligand Charge States in [L 2M] n- Complexes of Group 13 Ions. J Am Chem Soc 2019; 141:15792-15803. [PMID: 31510741 DOI: 10.1021/jacs.9b05602] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/21/2023]
Abstract
Water-stable organic mixed valence (MV) compounds have been prepared by the reaction of reduced bis(imino)pyridine ligands (I2P) with the trichloride salts of Al, Ga, and In. The coordination of two tridentate ligands to each ion affords octahedral complexes that are accessible with five ligand charge states: [(I2P0)(I2P-)M]2+, [(I2P-)2M]+, (I2P-)(I2P2-)M, [(I2P2-)2M]-, and [(I2P2-)(I2P3-)M]2-, and for M = Al only, [(I2P3-)2M]3-. In solid-state structures, the anionic members of the redox series are stabilized by the intercalation of Na+ cations within the ligands. The MV members of the redox series, (I2P-)(I2P2-)M and [(I2P2-)(I2P3-)M]2-, show characteristic intervalence transitions, in the near-infrared regions between 6800-7400 and 7800-9000 cm-1, respectively. Cyclic voltammetry (CV), NIR spectroscopic, and X-ray structural studies support the assignment of class II for compounds [(I2P2-)(I2P3-)M]2- and class III for M = Al and Ga in (I2P-)(I2P2-)M. All compounds containing a singly reduced I2P- ligand exhibit a sharp, low-energy transition in the 5100-5600 cm-1 region that corresponds to a π*-π* transition. CV studies demonstrate that the electron-transfer events in each of the redox series, Al, Ga, and In, span 2.2, 1.4, and 1.2 V, respectively.
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Affiliation(s)
- Amela Arnold
- Department of Chemistry , University of California-Davis , Davis , California 95616 , United States
| | - Tobias J Sherbow
- Department of Chemistry , University of California-Davis , Davis , California 95616 , United States
| | - Richard I Sayler
- Department of Chemistry , University of California-Davis , Davis , California 95616 , United States
| | - R David Britt
- Department of Chemistry , University of California-Davis , Davis , California 95616 , United States
| | - Emily J Thompson
- Department of Chemistry , University of California-Davis , Davis , California 95616 , United States
| | - M Teresa Muñoz
- Department of Chemistry , University of California-Davis , Davis , California 95616 , United States
| | - James C Fettinger
- Department of Chemistry , University of California-Davis , Davis , California 95616 , United States
| | - Louise A Berben
- Department of Chemistry , University of California-Davis , Davis , California 95616 , United States
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43
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Tian J, Zhang W. Synthesis, self-assembly and applications of functional polymers based on porphyrins. Prog Polym Sci 2019. [DOI: 10.1016/j.progpolymsci.2019.05.002] [Citation(s) in RCA: 70] [Impact Index Per Article: 14.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
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44
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Lee JK, Bulut I, Rickhaus M, Sheng Y, Li X, Han GGD, Briggs GAD, Anderson HL, Warner JH. Metal Atom Markers for Imaging Epitaxial Molecular Self-Assembly on Graphene by Scanning Transmission Electron Microscopy. ACS NANO 2019; 13:7252-7260. [PMID: 31117373 DOI: 10.1021/acsnano.9b02906] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/09/2023]
Abstract
Direct imaging of single molecules has to date been primarily achieved using scanning probe microscopy, with limited success using transmission electron microscopy due to electron beam damage and low contrast from the light elements that make up the majority of molecules. Here, we show single complex molecule interactions can be imaged using annular dark field scanning TEM (ADF-STEM) by inserting heavy metal markers of Pt atoms and detecting their positions. Using the high angle ADF-STEM Z1.7 contrast, combined with graphene as an electron transparent support, we track the 2D monolayer self-assembly of solution-deposited individual linear porphyrin hexamer (Pt-L6) molecules and reveal preferential alignment along the graphene zigzag direction. The epitaxial interactions between graphene and Pt-L6 drive a reduction in the interporphyrin distance to allow perfect commensuration with the graphene. These results demonstrate how single metal atom markers in complex molecules can be used to study large scale packing and chain bending at the single molecule level.
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Affiliation(s)
- Ja Kyung Lee
- Department of Materials , University of Oxford , Parks Road , Oxford OX1 3PH , United Kingdom
| | - Ibrahim Bulut
- Chemistry Research Laboratory, Department of Chemistry , University of Oxford , Oxford OX1 3TA , United Kingdom
| | - Michel Rickhaus
- Chemistry Research Laboratory, Department of Chemistry , University of Oxford , Oxford OX1 3TA , United Kingdom
| | - Yuewen Sheng
- Department of Materials , University of Oxford , Parks Road , Oxford OX1 3PH , United Kingdom
| | - Xiang Li
- Department of Chemistry , Brandeis University , Waltham , Massachusetts 02453 , United States
| | - Grace G D Han
- Department of Chemistry , Brandeis University , Waltham , Massachusetts 02453 , United States
| | - G Andrew D Briggs
- Department of Materials , University of Oxford , Parks Road , Oxford OX1 3PH , United Kingdom
| | - Harry L Anderson
- Chemistry Research Laboratory, Department of Chemistry , University of Oxford , Oxford OX1 3TA , United Kingdom
| | - Jamie H Warner
- Department of Materials , University of Oxford , Parks Road , Oxford OX1 3PH , United Kingdom
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45
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Xue S, Kuzuhara D, Aratani N, Yamada H. Synthesis of a Porphyrin(2.1.2.1) Nanobelt and Its Ability To Bind Fullerene. Org Lett 2019; 21:2069-2072. [DOI: 10.1021/acs.orglett.9b00329] [Citation(s) in RCA: 28] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Songlin Xue
- Graduate School of Science and Technology, Nara Institute of Science and Technology, 8916-5 Takayama-cho, Ikoma, Nara 630-0192, Japan
| | - Daiki Kuzuhara
- Faculty of Science and Engineering, Iwate University, 4-3-5 Ueda, Morioka, Iwate 020-8551, Japan
| | - Naoki Aratani
- Graduate School of Science and Technology, Nara Institute of Science and Technology, 8916-5 Takayama-cho, Ikoma, Nara 630-0192, Japan
| | - Hiroko Yamada
- Graduate School of Science and Technology, Nara Institute of Science and Technology, 8916-5 Takayama-cho, Ikoma, Nara 630-0192, Japan
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46
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Affiliation(s)
- Renée Haver
- Department of ChemistryUniversity of Oxford, Chemistry Research Laboratory Oxford OX1 3TA
| | - Harry L. Anderson
- Department of ChemistryUniversity of Oxford, Chemistry Research Laboratory Oxford OX1 3TA
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47
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Le Roy JJ, Cremers J, Thomlinson IA, Slota M, Myers WK, Horton PH, Coles SJ, Anderson HL, Bogani L. Tailored homo- and hetero- lanthanide porphyrin dimers: a synthetic strategy for integrating multiple spintronic functionalities into a single molecule. Chem Sci 2018; 9:8474-8481. [PMID: 30568771 PMCID: PMC6256854 DOI: 10.1039/c8sc03762k] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/22/2018] [Accepted: 10/17/2018] [Indexed: 01/24/2023] Open
Abstract
We present molecular magnetic systems that contain all elements necessary for spin-valve control in molecular spintronic devices in a single molecule.
We present the design, synthesis and magnetic properties of molecular magnetic systems that contain all elements necessary for spin-valve control in molecular spintronic devices in a single molecule. We investigate the static and dynamic magnetic properties and quantum spin properties of butadiyne-linked homo- and hetero-nuclear lanthanide-porphyrin dimers. A heterometallated porphyrin dimer containing both TbIII and DyIII centres is created rationally by the stepwise oxidative homocoupling of distinct lanthanide-porphyrin monomers. TbIII and DyIII mononuclear porphyrin complexes, homodimers and heterodimers all exhibit slow magnetic relaxation below 10 kelvin under a static magnetic field. The coherence times for GdIII porphyrin monomers and dimers are found to be in excess of 3.0 μs at 2 K, allowing distinct magnetic manipulations in low temperature transport experiments.
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Affiliation(s)
- Jennifer J Le Roy
- Department of Materials , University of Oxford , 16 Parks Rd , OX1 3PH , Oxford , UK .
| | - Jonathan Cremers
- Department of Chemistry , University of Oxford , Chemistry Research Laboratory , Mansfield Road , Oxford OX1 3TA , UK
| | - Isabel A Thomlinson
- Department of Chemistry , University of Oxford , Chemistry Research Laboratory , Mansfield Road , Oxford OX1 3TA , UK
| | - Michael Slota
- Department of Materials , University of Oxford , 16 Parks Rd , OX1 3PH , Oxford , UK .
| | - William K Myers
- Centre for Advanced ESR , Department of Chemistry , University of Oxford , Inorganic Chemistry Laboratory , South Parks Road , Oxford , OX1 3QR , UK
| | - Peter H Horton
- National Crystallography Service , School of Chemistry , University of Southampton , Southampton , SO17 1BJ , UK
| | - Simon J Coles
- National Crystallography Service , School of Chemistry , University of Southampton , Southampton , SO17 1BJ , UK
| | - Harry L Anderson
- Department of Chemistry , University of Oxford , Chemistry Research Laboratory , Mansfield Road , Oxford OX1 3TA , UK
| | - Lapo Bogani
- Department of Materials , University of Oxford , 16 Parks Rd , OX1 3PH , Oxford , UK .
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48
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Abstract
This Account is about templates as construction tools: molecules for making molecules. A template organizes the reactants and provides information to promote formation of a specific product, but it is not part of the final product. We have developed many different strategies for using oligopyridines as templates for the synthesis of alkyne-linked π-conjugated metalloporphyrin oligomers. These compounds include some of the largest macrocycles ever synthesized, such as a 50-porphyrin ring with a diameter of 21 nm containing a ring of 750 C-C bonds. Metalloporphyrins are excellent models for exploring template directed synthesis, as they can be functionalized in many different positions and the central metal (typically Zn or Mg) provides a handle for coordination to templates. Classical template-directed macrocyclization reactions have a 1:1 complementarity between the template and the product. This strategy works well for preparing nanorings of 5-7 porphyrin units, but larger templates are laborious to synthesize. Rings of 8 or more porphyrin units are most easily prepared using "nonclassical" strategies, in which several small templates work together to direct the formation of a large ring. In the Vernier approach, a mismatch between the number of binding sites on the template and the building block leads to a mathematical amplification of the length scale: the number of binding sites in the product is the lowest common multiple of those in the template and the building block. For example, a 40-porphyrin ring can be prepared by coupling a linear decamer in the presence of an octadentate template. Linear Vernier templating opens up intriguing possibilities for self-replication. When several small radial oligopyridine templates bind inside a large nanoring they can form complexes with some vacant coordination sites that display correlated motion like the caterpillar tracks of a bulldozer. These caterpillar track complexes can be used in template-directed synthesis and they provide the most convenient route to 8- and 10-porphyrin rings. Russian doll complexes provide another strategy for template-directed synthesis: a number of specifically designed ligands bind to a central nanoring to form a template for constructing a larger concentric nanoring. The same oligopyridine templates that are used to prepare nanorings can also be used to synthesize three-dimensional nanotubes and nanoballs. Again, nonclassical approaches, in which several small templates work together cooperatively, are much simpler than creating a single large template with sufficient binding sites to define the whole geometry of the product. Oligopyridine ligands can also be used as shadow mask templates to control the demetalation of magnesium porphyrin nanorings, because metal centers that are not coordinated by the template can be selectively demetalated with acid. Thus, the template forms a permanent shadow on the porphyrin nanostructure that remains after the template has been removed. Shadow mask templates provide a simple route to heterometalated molecular architectures. The insights emerging from these studies are widely applicable, and there are many opportunities for inventing new ways of using templates to control reactions.
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Affiliation(s)
- Pernille S. Bols
- Chemistry Research Laboratory, Department of Chemistry, Oxford University, Mansfield Road, Oxford OX1 3TA, United Kingdom
| | - Harry L. Anderson
- Chemistry Research Laboratory, Department of Chemistry, Oxford University, Mansfield Road, Oxford OX1 3TA, United Kingdom
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49
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Ivanov MV, Reid SA, Rathore R. Game of Frontier Orbitals: A View on the Rational Design of Novel Charge-Transfer Materials. J Phys Chem Lett 2018; 9:3978-3986. [PMID: 29952570 DOI: 10.1021/acs.jpclett.8b01093] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/08/2023]
Abstract
Since the first application of frontier molecular orbitals (FMOs) to rationalize stereospecificity of pericyclic reactions, FMOs have remained at the forefront of chemical theory. Yet, the practical application of FMOs in the rational design and synthesis of novel charge transfer materials remains under-appreciated. In this Perspective, we demonstrate that molecular orbital theory is a powerful and universal tool capable of rationalizing the observed redox/optoelectronic properties of various aromatic hydrocarbons in the context of their application as charge-transfer materials. Importantly, the inspection of FMOs can provide instantaneous insight into the interchromophoric electronic coupling and polaron delocalization in polychromophoric assemblies, and therefore is invaluable for the rational design and synthesis of novel materials with tailored properties.
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Affiliation(s)
- Maxim V Ivanov
- Department of Chemistry , Marquette University , P.O. Box 1881, Milwaukee , Wisconsin 53201-1881 , United States
| | - Scott A Reid
- Department of Chemistry , Marquette University , P.O. Box 1881, Milwaukee , Wisconsin 53201-1881 , United States
| | - Rajendra Rathore
- Department of Chemistry , Marquette University , P.O. Box 1881, Milwaukee , Wisconsin 53201-1881 , United States
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50
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Cremers J, Haver R, Rickhaus M, Gong JQ, Favereau L, Peeks MD, Claridge TDW, Herz LM, Anderson HL. Template-Directed Synthesis of a Conjugated Zinc Porphyrin Nanoball. J Am Chem Soc 2018; 140:5352-5355. [PMID: 29638125 DOI: 10.1021/jacs.8b02552] [Citation(s) in RCA: 55] [Impact Index Per Article: 9.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
We report the template-directed synthesis of a π-conjugated 14-porphyrin nanoball. This structure consists of two intersecting nanorings containing six and 10 porphyrin units. Fluorescence upconversion spectroscopy experiments demonstrate that electronic excitation delocalizes over the whole three-dimensional π system in less than 0.3 ps if the nanoball is bound to its templates or over 2 ps if the nanoball is empty.
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Affiliation(s)
- Jonathan Cremers
- Chemistry Research Laboratory, Department of Chemistry , University of Oxford , Oxford OX1 3TA , United Kingdom
| | - Renée Haver
- Chemistry Research Laboratory, Department of Chemistry , University of Oxford , Oxford OX1 3TA , United Kingdom
| | - Michel Rickhaus
- Chemistry Research Laboratory, Department of Chemistry , University of Oxford , Oxford OX1 3TA , United Kingdom
| | - Juliane Q Gong
- Clarendon Laboratory, Department of Physics , University of Oxford , Oxford OX1 3PU , United Kingdom
| | - Ludovic Favereau
- Chemistry Research Laboratory, Department of Chemistry , University of Oxford , Oxford OX1 3TA , United Kingdom
| | - Martin D Peeks
- Chemistry Research Laboratory, Department of Chemistry , University of Oxford , Oxford OX1 3TA , United Kingdom
| | - Tim D W Claridge
- Chemistry Research Laboratory, Department of Chemistry , University of Oxford , Oxford OX1 3TA , United Kingdom
| | - Laura M Herz
- Clarendon Laboratory, Department of Physics , University of Oxford , Oxford OX1 3PU , United Kingdom
| | - Harry L Anderson
- Chemistry Research Laboratory, Department of Chemistry , University of Oxford , Oxford OX1 3TA , United Kingdom
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