1
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Xu X, Marlton SJP, Flint KL, Hudson RJ, Keene FR, Hall CR, Smith TA. Photophysical Studies of Helicate and Mesocate Double-Stranded Dinuclear Ru(II) Complexes. J Phys Chem A 2024. [PMID: 38640443 DOI: 10.1021/acs.jpca.4c01996] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/21/2024]
Abstract
The metal-ligand charge transfer (3MLCT) and phosphorescence-quenching metal-centered (3MC) states of the helicate and mesocate diastereoisomers of a double-stranded dinuclear polypyridylruthenium(II) complex have been investigated using ultrafast transient absorption spectroscopy. At 294 K, transient signals of the helicate decayed significantly slower than those of the mesocate, whereas at 77 K, no clear contrast in kinetics was observed. Contributions to excited-state decay from high-lying 3MLCT states were identified at both temperatures. Spectroscopic data (294 K) suggest that the 3MC state of the helicate lies above the 3MLCT and that the reverse is true for the mesocate; this was further validated by density functional theory calculations. The stabilization of the 3MC state relative to the 3MLCT state in the mesocate was explained by a reduction in ligand field strength due to distortion near the ligand bridge, which causes further deviation from octahedral geometry compared to the helicate. This work illustrates how minor structural differences can significantly influence excited state dynamics.
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Affiliation(s)
- Xinyue Xu
- School of Chemistry, The University of Melbourne, Parkville, Victoria 3010, Australia
- ARC Centre of Excellence in Exciton Science, Parkville, Victoria 3010, Australia
| | - Samuel J P Marlton
- School of Chemistry, The University of Melbourne, Parkville, Victoria 3010, Australia
| | - Kate L Flint
- Discipline of Chemistry, School of Physics, Chemistry and Earth Sciences, The University of Adelaide, South Australia 5005, Australia
| | - Rohan J Hudson
- School of Chemistry, The University of Melbourne, Parkville, Victoria 3010, Australia
- ARC Centre of Excellence in Exciton Science, Parkville, Victoria 3010, Australia
| | - F Richard Keene
- Discipline of Chemistry, School of Physics, Chemistry and Earth Sciences, The University of Adelaide, South Australia 5005, Australia
| | - Christopher R Hall
- School of Chemistry, The University of Melbourne, Parkville, Victoria 3010, Australia
- ARC Centre of Excellence in Exciton Science, Parkville, Victoria 3010, Australia
| | - Trevor A Smith
- School of Chemistry, The University of Melbourne, Parkville, Victoria 3010, Australia
- ARC Centre of Excellence in Exciton Science, Parkville, Victoria 3010, Australia
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2
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Yin CW, Tsai MK, Chen YJ. Low-Temperature Observation of the Excited-State Decay of Ruthenium-(Mono-2,2':6',2″-Terpyridine) Ions with Innocent Ligands: DFT Modeling of an 3MLCT- 3MC Intersystem Crossing Pathway. ACS OMEGA 2023; 8:11623-11633. [PMID: 37008138 PMCID: PMC10061511 DOI: 10.1021/acsomega.3c01006] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 02/14/2023] [Accepted: 02/28/2023] [Indexed: 06/19/2023]
Abstract
The synthesis, electrochemistry, and photophysical characterization of five 2,2':6',2″-terpyridine ruthenium complexes (Ru-tpy complexes) is reported. The electrochemical and photophysical behavior varied depending on the ligands, i.e., amine (NH3), acetonitrile (AN), and bis(pyrazolyl)methane (bpm), for this series of Ru-tpy complexes. The target [Ru(tpy)(AN)3]2+ and [Ru(tpy)(bpm)(AN)]2+ complexes were found to have low-emission quantum yields in low-temperature observations. To better understand this phenomenon, density functional theory (DFT) calculations were performed to simulate the singlet ground state (S0), Te, and metal-centered excited states (3MC) of these complexes. The calculated energy barriers between Te and the low-lying 3MC state for [Ru(tpy)(AN)3]2+ and [Ru(tpy)(bpm)(AN)]2+ provided clear evidence in support of their emitting state decay behavior. Developing a knowledge of the underlying photophysics of these Ru-tpy complexes will allow new complexes to be designed for use in photophysical and photochemical applications in the future.
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Affiliation(s)
- Chi-Wei Yin
- Department
of Chemistry, Fu-Jen Catholic University, New Taipei City 24205, Taiwan, ROC
| | - Ming-Kang Tsai
- Department
of Chemistry, Fu-Jen Catholic University, New Taipei City 24205, Taiwan, ROC
- Department
of Chemistry, National Taiwan Normal University, Taipei 11677, Taiwan, ROC
| | - Yuan Jang Chen
- Department
of Chemistry, Fu-Jen Catholic University, New Taipei City 24205, Taiwan, ROC
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3
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Schüssler L, Israil RGE, Hütchen P, Thiel WR, Diller R, Riehn C. Ultrafast spectroscopy of Ru II polypyridine complexes in the gas phase and the liquid phase: [Ru(2,2'-bipyridine) 2(nicotinamide) 2] 2. Phys Chem Chem Phys 2023; 25:4899-4914. [PMID: 36722394 DOI: 10.1039/d2cp03765c] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023]
Abstract
[Ru(bipyridine)2(nicotinamide)2]2+ (1) and its monoaqua-complex [Ru(bipyridine)2(nicotinamide)(H2O)]2+ (2) were spectroscopically studied for the first time in the gas phase by static and time resolved UV photodissociation spectroscopy, observing nicotinamide and H2O ligand dissociation for 1 and 2, respectively. Both processes and their ultrafast dynamics were investigated in parallel by transient absorption spectroscopy in aqueous solution. The latter data were newly acquired for the long-wavelength MLCT band excitation of 1 and provide novel ultrafast ligand dissociation results for 2, confirming the gas phase results, i.e., exclusive H2O cleavage over nicotinamide loss. Similar apparent time constants in the sub-ps and few ps ranges were obtained for 1 in both phases, whereas a larger time constant of ca. two hundreds of ps for the ground state recovery was observed exclusively in the solution phase. Our reaction scheme accounts for faster dissociation dynamics in the gas phase by energetical lowering of the 3MC vs. the 3MLCT states by lack of solvent stabilization of the latter. Based on the apparent time constants, we favour, for the solution dynamics, a fast bimodal vibrational deactivation in the 3MLCT/3MC manifolds and a slow dissociation obfuscated by the ground state recovery. This is substantiated by a similar reaction scheme proposed for the ultrafast dynamics of 2, resulting in a new assignment for transient absorption features with λ > 550 nm to the 3MC manifold, and a common kinetic description for 1 and 2. Computations at the TD-DFT/cc-PVTZ/MDF28 level support our spectroscopic findings and the suggested deactivation pathways.
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Affiliation(s)
- L Schüssler
- Department of Physics, Technische Universität Kaiserslautern (TUK), Erwin-Schrödinger-Str. 46, D-67663 Kaiserslautern, Germany.
| | - R G E Israil
- Department of Chemistry, Technische Universität Kaiserslautern (TUK), Erwin-Schrödinger-Str. 52, D-67663 Kaiserslautern, Germany.
| | - P Hütchen
- Department of Chemistry, Technische Universität Kaiserslautern (TUK), Erwin-Schrödinger-Str. 54, D-67663 Kaiserslautern, Germany
| | - W R Thiel
- Department of Chemistry, Technische Universität Kaiserslautern (TUK), Erwin-Schrödinger-Str. 54, D-67663 Kaiserslautern, Germany
| | - R Diller
- Department of Physics, Technische Universität Kaiserslautern (TUK), Erwin-Schrödinger-Str. 46, D-67663 Kaiserslautern, Germany.
| | - C Riehn
- Department of Chemistry, Technische Universität Kaiserslautern (TUK), Erwin-Schrödinger-Str. 52, D-67663 Kaiserslautern, Germany. .,Research Center OPTIMAS, Erwin-Schrödinger Str. 46, D-67663 Kaiserslautern, Germany
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4
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Yarranton JT, McCusker JK. Ligand-Field Spectroscopy of Co(III) Complexes and the Development of a Spectrochemical Series for Low-Spin d 6 Charge-Transfer Chromophores. J Am Chem Soc 2022; 144:12488-12500. [PMID: 35749670 DOI: 10.1021/jacs.2c04945] [Citation(s) in RCA: 18] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
Abstract
A study of a series of six-coordinate Co(III) complexes has been carried out to quantify spectroscopic parameters for a range of ligands that are commonly employed to realize strong charge-transfer absorptions in low-spin, d6 systems. Identification of any three ligand-field transitions allows for the determination of the splitting parameter (10 Dq) as well as the Racah B and C parameters for a given compound. The data revealed a relatively small spread in the magnitude of 10 Dq, ranging from ca. 23 000 cm-1 in the case of [Co(pyrro-bpy)3]3+ (where pyrro-bpy is 4,4'-dipyrrolidinyl-2,2'-bipyridine) to ca. 26 000 cm-1 for [Co(terpy)2]3+ (where terpy is 2,2':6',2″-terpyridine). Significantly, trends across the series suggest that polypyridyl ligands behave as net π-donors when interacting with Co(III), in contrast to the net π-accepting character they exhibit when bound to second- and third-row metals. The influence of strong σ donation associated with carbene-based ligands was evident from the data acquired for [Co(BMeImPy)2]3+ (where BMeImPy is 3,3'-(pyridine-2,6-diyl)bis(1-methyl-1H-3-imidazolium)), where a 10 Dq value of ca. 30 000 cm-1 was determined. Spectroscopic data were also analyzed for [Fe(bpy)3]2+ using the results on [Co(bpy)3]3+ as a reference point. A value for 10 Dq of 21 000 cm-1 was estimated, indicating a reduction in the ligand-field strength of ca. 3000 cm-1 upon replacing Co(III) with Fe(II). We suggest that this approach of taking advantage of the blueshift of the charge-transfer feature in Co(III) complexes to reveal otherwise obscured ligand-field bands can be a useful tool for the development of new ligand systems to expand the photofunctionality of first-row transition-metal-based chromophores.
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Affiliation(s)
- Jonathan T Yarranton
- Department of Chemistry, Michigan State University, 578 South Shaw Lane, East Lansing, Michigan 48824, United States
| | - James K McCusker
- Department of Chemistry, Michigan State University, 578 South Shaw Lane, East Lansing, Michigan 48824, United States
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5
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Jain N, Mary A, Manjunath V, Sakla R, Devan RS, Jose DA, Naziruddin AR. Ruthenium (II) Complexes Bearing Heteroleptic Terpyridine Ligands: Synthesis, Photophysics and Solar Energy Conversion. Eur J Inorg Chem 2021. [DOI: 10.1002/ejic.202100817] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Affiliation(s)
- Nimisha Jain
- Inorganic Materials and Catalysis Laboratory Department of Chemistry Malaviya National Institute of Technology Jaipur JLN Marg 302017 Jaipur India
| | - Angelina Mary
- Inorganic Materials and Catalysis Laboratory Department of Chemistry Malaviya National Institute of Technology Jaipur JLN Marg 302017 Jaipur India
| | - Vishesh Manjunath
- Department of Metallurgy Engineering and Materials Science Indian Institute of Technology Indore Khandwa Road Simrol 453552 Indore India
| | - Rahul Sakla
- National Institute of Technology Kurukshetra Haryana India
| | - Rupesh S. Devan
- Department of Metallurgy Engineering and Materials Science Indian Institute of Technology Indore Khandwa Road Simrol 453552 Indore India
| | - D. Amilan Jose
- National Institute of Technology Kurukshetra Haryana India
| | - Abbas Raja Naziruddin
- Inorganic Materials and Catalysis Laboratory Department of Chemistry Malaviya National Institute of Technology Jaipur JLN Marg 302017 Jaipur India
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6
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Seidler B, Sittig M, Zens C, Tran JH, Müller C, Zhang Y, Schneider KRA, Görls H, Schubert A, Gräfe S, Schulz M, Dietzek B. Modulating the Excited-State Decay Pathways of Cu(I) 4 H-Imidazolate Complexes by Excitation Wavelength and Ligand Backbone. J Phys Chem B 2021; 125:11498-11511. [PMID: 34617757 DOI: 10.1021/acs.jpcb.1c06902] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Cu(I) 4H-imidazolato complexes are excellent photosensitizers with broad and intense light absorption properties, based on an earth-abundant metal, and hold great promise as photosensitizers in artificial photosynthesis and for accumulation of redox equivalents. In this study, the excited-state relaxation dynamics of three novel heteroleptic Cu(I) 4H-imidazolato complexes with phenyl, tolyl, and mesityl side groups are systematically investigated by femtosecond and nanosecond time-resolved transient absorption spectroscopy and theoretical methods, complemented by steady-state absorption spectroscopy and (spectro)electrochemistry. After photoexcitation into the metal-to-ligand charge transfer (MLCT) and intraligand charge transfer absorption band, fast (0.6-1 ps) intersystem crossing occurs into the triplet MLCT manifold. The triplet-state population relaxes via the geometrical planarization of the N-aryl rings on the Cu(I) 4H-imidazolato complexes. Depending on the initial Franck-Condon state, the remaining small singlet state population relaxes into two geometrically distinct minima geometries with similar energy, S1/2,relax and S3/4,relax. Subsequent ground-state recovery from S1/2,relax and internal conversion from S3/4,relax to S1/2,relax take place on a 100 ps time scale. The internal conversion can be understood as hole transfer from a dyz-orbital to a dxz-orbital, which is accompanied with the structural reorganization of the coordination environment. Generally, the photophysical processes are determined by the steric hindrance of the side groups on the ligands. And the excited singlet-state pathways are dependent on the excitation wavelength.
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Affiliation(s)
- Bianca Seidler
- Institute of Physical Chemistry, Friedrich Schiller University Jena, Helmholtzweg 4, 07743 Jena, Germany.,Department Functional Interfaces, Leibniz Institute of Photonic Technology Jena (Leibniz-IPHT), Albert-Einstein-Str. 9, 07745 Jena, Germany
| | - Maria Sittig
- Institute of Physical Chemistry, Friedrich Schiller University Jena, Helmholtzweg 4, 07743 Jena, Germany.,Department Functional Interfaces, Leibniz Institute of Photonic Technology Jena (Leibniz-IPHT), Albert-Einstein-Str. 9, 07745 Jena, Germany
| | - Clara Zens
- Institute of Physical Chemistry, Friedrich Schiller University Jena, Helmholtzweg 4, 07743 Jena, Germany
| | - Jens H Tran
- Institute of Physical Chemistry, Friedrich Schiller University Jena, Helmholtzweg 4, 07743 Jena, Germany
| | - Carolin Müller
- Institute of Physical Chemistry, Friedrich Schiller University Jena, Helmholtzweg 4, 07743 Jena, Germany.,Department Functional Interfaces, Leibniz Institute of Photonic Technology Jena (Leibniz-IPHT), Albert-Einstein-Str. 9, 07745 Jena, Germany
| | - Ying Zhang
- Institute of Physical Chemistry, Friedrich Schiller University Jena, Helmholtzweg 4, 07743 Jena, Germany
| | - Kilian R A Schneider
- Department Functional Interfaces, Leibniz Institute of Photonic Technology Jena (Leibniz-IPHT), Albert-Einstein-Str. 9, 07745 Jena, Germany
| | - Helmar Görls
- Institute of Inorganic and Analytical Chemistry, Friedrich Schiller University Jena, Humboldtstr. 8, 07743 Jena, Germany
| | - Alexander Schubert
- Institute of Physical Chemistry, Friedrich Schiller University Jena, Helmholtzweg 4, 07743 Jena, Germany
| | - Stefanie Gräfe
- Institute of Physical Chemistry, Friedrich Schiller University Jena, Helmholtzweg 4, 07743 Jena, Germany.,Fraunhofer Institute for Applied Optics and Precision Engineering (Fraunhofer IOF), Albert-Einstein-Str.7, 07745 Jena, Germany
| | - Martin Schulz
- Institute of Physical Chemistry, Friedrich Schiller University Jena, Helmholtzweg 4, 07743 Jena, Germany.,Department Functional Interfaces, Leibniz Institute of Photonic Technology Jena (Leibniz-IPHT), Albert-Einstein-Str. 9, 07745 Jena, Germany
| | - Benjamin Dietzek
- Institute of Physical Chemistry, Friedrich Schiller University Jena, Helmholtzweg 4, 07743 Jena, Germany.,Department Functional Interfaces, Leibniz Institute of Photonic Technology Jena (Leibniz-IPHT), Albert-Einstein-Str. 9, 07745 Jena, Germany.,Centre for Energy and Environmental Chemistry Jena (CEEC-Jena), Friedrich Schiller University Jena, Philosophenweg 7a, 07743 Jena, Germany
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7
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Paulus BC, Nielsen KC, Tichnell CR, Carey MC, McCusker JK. A Modular Approach to Light Capture and Synthetic Tuning of the Excited-State Properties of Fe(II)-Based Chromophores. J Am Chem Soc 2021; 143:8086-8098. [PMID: 34014077 DOI: 10.1021/jacs.1c02451] [Citation(s) in RCA: 18] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
The development of chromophores based on earth-abundant transition metals whose photophysical properties are dominated by their charge-transfer excited states has inspired considerable research over the past decade. One challenge associated with this effort is satisfying the dual requirements of a strong ligand field and chemical tunability of the compound's absorptive cross-section. Herein we explore one possible approach using a heteroleptic compositional motif that combines both of these attributes into a single compound. With the parent complex [Fe(phen)3]2+ (1; where phen is 1,10-phenanthroline) as the starting material, replacement of one of the phen ligands for two cyanides to obtain Fe(phen)2(CN)2 (2) allows for conversion to [Fe(phen)2(C4H10N4)]2+ (3), a six-coordinate Fe(II) complex whose coordination sphere consists of two chelating polypyridyl ligands and one bidentate carbene-based donor. Ground-state absorption spectra of all three compounds exhibit 1A1 → 1MLCT transition(s) associated with the phen ligands that are relatively insensitive to the identity of the third counterligand(s). Ultrafast time-resolved electronic absorption measurements revealed lifetimes for the MLCT excited states of compounds 1 and 2 of 180 ± 30 and 250 ± 90 fs, respectively, values that are typical for iron(II)-based polypyridyl complexes. The corresponding kinetics for compound 3 were substantially slower at 7.4 ± 0.9 ps; the spectral evolution associated with these dynamics confirms that these kinetics are tracking the MLCT excited state and, more importantly, are coupled to ground-state recovery from this excited state. The data are interpreted in terms of a modulation of the relative energies of the MLCT and ligand-field states across the series, leading to a systematic destabilization of metal-localized ligand-field excited states such that the low-energy portions of the charge-transfer and ligand-field manifolds are at or near an energetic inversion point in compound 3. We believe these results illustrate the potential for a modular, orthogonal approach to chromophore design in which part of the coordination sphere can be targeted for light absorption while another can be used to tune electronic-state energetics.
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Affiliation(s)
- Bryan C Paulus
- Department of Chemistry, Michigan State University 578 South Shaw Lane, East Lansing, Michigan 48824, United States
| | - Karl C Nielsen
- Department of Chemistry, Michigan State University 578 South Shaw Lane, East Lansing, Michigan 48824, United States
| | - Christopher R Tichnell
- Department of Chemistry, Michigan State University 578 South Shaw Lane, East Lansing, Michigan 48824, United States
| | - Monica C Carey
- Department of Chemistry, Michigan State University 578 South Shaw Lane, East Lansing, Michigan 48824, United States
| | - James K McCusker
- Department of Chemistry, Michigan State University 578 South Shaw Lane, East Lansing, Michigan 48824, United States
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8
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Cheshire TP, Brennaman MK, Giokas PG, Zigler DF, Moran AM, Papanikolas JM, Meyer GJ, Meyer TJ, Houle FA. Ultrafast Relaxations in Ruthenium Polypyridyl Chromophores Determined by Stochastic Kinetics Simulations. J Phys Chem B 2020; 124:5971-5985. [DOI: 10.1021/acs.jpcb.0c03110] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Thomas P. Cheshire
- Chemical Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720, United States
| | - M. Kyle Brennaman
- Department of Chemistry, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina 27599, United States
| | - Paul G. Giokas
- Coherent Inc., Santa Clara, California 95054, United States
| | - David F. Zigler
- Chemistry & Biochemistry Department, California Polytechnic State University, San Luis Obispo, California 93407, United States
| | - Andrew M. Moran
- Department of Chemistry, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina 27599, United States
| | - John M. Papanikolas
- Department of Chemistry, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina 27599, United States
| | - Gerald J. Meyer
- Department of Chemistry, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina 27599, United States
| | - Thomas J. Meyer
- Department of Chemistry, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina 27599, United States
| | - Frances A. Houle
- Chemical Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720, United States
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9
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Loftus LM, Rack JJ, Turro C. Photoinduced ligand dissociation follows reverse energy gap law: nitrile photodissociation from low energy 3MLCT excited states. Chem Commun (Camb) 2020; 56:4070-4073. [PMID: 32159547 DOI: 10.1039/c9cc10095d] [Citation(s) in RCA: 22] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
A series of Ru(ii)-terpyridine complexes containing electron-donating bidentate ligands are able to effectively photodissociate nitrile ligands using red light. A spectroscopic investigation of these complexes reveal that they follow anti-energy gap law behavior, providing further evidence that population of 3LF excited states is not necessary for photoinduced nitrile dissociation.
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Affiliation(s)
- Lauren M Loftus
- Department of Chemistry and Biochemistry, The Ohio State University, Columbus, Ohio 43210, USA.
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10
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Luo Y, Wächtler M, Barthelmes K, Winter A, Schubert US, Dietzek B. Superexchange in the fast lane - intramolecular electron transfer in a molecular triad occurs by conformationally gated superexchange. Chem Commun (Camb) 2019; 55:5251-5254. [PMID: 30990492 DOI: 10.1039/c9cc01886g] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Photoinduced electron transfer via hopping is generally considered to have a stronger temperature dependence than electron transfer via superexchange. However, in this work, an opposite trend of the temperature dependence is observed. This unexpected result is rationalized by considering the specific geometrical and electronic structure of the Ru-bis(terpyridine) photosensitizer.
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Affiliation(s)
- Yusen Luo
- Institute of Physical Chemistry and Abbe Center of Photonics, Friedrich-Schiller-University Jena, Helmholtzweg 4, 07743 Jena, Germany and Department Functional Interfaces, Leibniz Institute of Photonic Technology (IPHT), Albert-Einstein-Straβe 9, 07745 Jena, Germany.
| | - Maria Wächtler
- Institute of Physical Chemistry and Abbe Center of Photonics, Friedrich-Schiller-University Jena, Helmholtzweg 4, 07743 Jena, Germany and Department Functional Interfaces, Leibniz Institute of Photonic Technology (IPHT), Albert-Einstein-Straβe 9, 07745 Jena, Germany.
| | - Kevin Barthelmes
- Laboratory of Organic and Macromolecular Chemistry (IOMC), Friedrich-Schiller-University Jena, Humboldtstraβe 10, 07743 Jena, Germany and Center for Energy and Environmental Chemistry Jena (CEEC Jena), Philosophenweg 7a, 07743 Jena, Germany
| | - Andreas Winter
- Laboratory of Organic and Macromolecular Chemistry (IOMC), Friedrich-Schiller-University Jena, Humboldtstraβe 10, 07743 Jena, Germany and Center for Energy and Environmental Chemistry Jena (CEEC Jena), Philosophenweg 7a, 07743 Jena, Germany
| | - Ulrich S Schubert
- Laboratory of Organic and Macromolecular Chemistry (IOMC), Friedrich-Schiller-University Jena, Humboldtstraβe 10, 07743 Jena, Germany and Center for Energy and Environmental Chemistry Jena (CEEC Jena), Philosophenweg 7a, 07743 Jena, Germany
| | - Benjamin Dietzek
- Institute of Physical Chemistry and Abbe Center of Photonics, Friedrich-Schiller-University Jena, Helmholtzweg 4, 07743 Jena, Germany and Department Functional Interfaces, Leibniz Institute of Photonic Technology (IPHT), Albert-Einstein-Straβe 9, 07745 Jena, Germany. and Center for Energy and Environmental Chemistry Jena (CEEC Jena), Philosophenweg 7a, 07743 Jena, Germany
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11
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Zedler L, Krieck S, Kupfer S, Dietzek B. Resonance Raman Spectro-Electrochemistry to Illuminate Photo-Induced Molecular Reaction Pathways. Molecules 2019; 24:molecules24020245. [PMID: 30634707 PMCID: PMC6358810 DOI: 10.3390/molecules24020245] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2018] [Revised: 01/04/2019] [Accepted: 01/05/2019] [Indexed: 11/16/2022] Open
Abstract
Electron transfer reactions play a key role for artificial solar energy conversion, however, the underlying reaction mechanisms and the interplay with the molecular structure are still poorly understood due to the complexity of the reaction pathways and ultrafast timescales. In order to investigate such light-induced reaction pathways, a new spectroscopic tool has been applied, which combines UV-vis and resonance Raman spectroscopy at multiple excitation wavelengths with electrochemistry in a thin-layer electrochemical cell to study [RuII(tbtpy)₂]2+ (tbtpy = tri-tert-butyl-2,2':6',2''-terpyridine) as a model compound for the photo-activated electron donor in structurally related molecular and supramolecular assemblies. The new spectroscopic method substantiates previous suggestions regarding the reduction mechanism of this complex by localizing photo-electrons and identifying structural changes of metastable intermediates along the reaction cascade. This has been realized by monitoring selective enhancement of Raman-active vibrations associated with structural changes upon electronic absorption when tuning the excitation wavelength into new UV-vis absorption bands of intermediate structures. Additional interpretation of shifts in Raman band positions upon reduction with the help of quantum chemical calculations provides a consistent picture of the sequential reduction of the individual terpyridine ligands, i.e., the first reduction results in the monocation [(tbtpy)Ru(tbtpy•)]⁺, while the second reduction generates [(tbtpy•)Ru(tbtpy•)]0 of triplet multiplicity. Therefore, the combination of this versatile spectro-electrochemical tool allows us to deepen the fundamental understanding of light-induced charge transfer processes in more relevant and complex systems.
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Affiliation(s)
- Linda Zedler
- Department Functional Interfaces, Leibniz Institute of Photonic Technology Jena, Albert-Einstein-Strasse 9, 07745 Jena, Germany.
| | - Sven Krieck
- Institute of Inorganic and Analytical Chemistry, Friedrich-Schiller-University Jena, Humboldtstrasse 8, 07743 Jena, Germany.
| | - Stephan Kupfer
- Institute of Physical Chemistry and Abbe Center of Photonics, Friedrich-Schiller-University Jena, Helmholtzweg 4, 07743 Jena, Germany.
| | - Benjamin Dietzek
- Department Functional Interfaces, Leibniz Institute of Photonic Technology Jena, Albert-Einstein-Strasse 9, 07745 Jena, Germany.
- Institute of Physical Chemistry and Abbe Center of Photonics, Friedrich-Schiller-University Jena, Helmholtzweg 4, 07743 Jena, Germany.
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12
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Pettersson Rimgard B, Föhlinger J, Petersson J, Lundberg M, Zietz B, Woys AM, Miller SA, Wasielewski MR, Hammarström L. Ultrafast interligand electron transfer in cis-[Ru(4,4'-dicarboxylate-2,2'-bipyridine) 2(NCS) 2] 4- and implications for electron injection limitations in dye sensitized solar cells. Chem Sci 2018; 9:7958-7967. [PMID: 30430000 PMCID: PMC6201818 DOI: 10.1039/c8sc00274f] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/17/2018] [Accepted: 08/13/2018] [Indexed: 11/22/2022] Open
Abstract
Interligand electron transfer (ILET) of the lowest metal-to-ligand charge transfer (MLCT) state of N712 (cis-[Ru(dcb)2(NCS)2]4-, where dcb = 4,4'-dicarboxylate-2,2'-bipyridine) in a deuterated acetonitrile solution has been studied by means of femtosecond transient absorption anisotropy in the mid-IR. Time-independent B3LYP density functional calculations were performed to assign vibrational bands and determine their respective transition dipole moments. The transient absorption spectral band at 1327 cm-1, assigned to a symmetric carboxylate stretch, showed significant anisotropy. A rapid anisotropy increase (τ 1 ≈ 2 ps) was tentatively assigned to vibrational and solvent relaxation, considering the excess energy available after the excited singlet-triplet conversion. Thereafter, the anisotropy decayed to zero with a time constant τ 2 ≈ 240 ps, which was assigned to the rotational correlation time of the complex in deuterated acetonitrile. No other distinctive changes to the anisotropy were observed and the amplitude of the slow component at time zero agrees well with that predicted for a random mixture of MLCT localization on either of the two dcb ligands. The results therefore suggest that MLCT randomization over the two dcb ligands occurs on the sub-ps time scale. This is much faster than proposed by previous reports on the related N3 complex [Benkö et al., J. Phys. Chem. B, 2004, 108, 2862, and Waterland et al., J. Phys. Chem. A, 2001, 105, 4019], but in agreement with that found by Wallin and co-workers [J. Phys. Chem. A, 2005, 109, 4697] for the [Ru(bpy)3]2+ (bpy = 2,2'-bipyridine) complex. This suggests that electron injection from the excited dye into TiO2 in dye-sensitized solar cells is not limited by ILET.
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Affiliation(s)
- Belinda Pettersson Rimgard
- Department of Chemistry - Ångström Laboratory , Uppsala University , Box 523 , SE75120 Uppsala , Sweden .
| | - Jens Föhlinger
- Department of Chemistry - Ångström Laboratory , Uppsala University , Box 523 , SE75120 Uppsala , Sweden .
| | - Jonas Petersson
- Department of Chemistry - Ångström Laboratory , Uppsala University , Box 523 , SE75120 Uppsala , Sweden .
| | - Marcus Lundberg
- Department of Chemistry - Ångström Laboratory , Uppsala University , Box 523 , SE75120 Uppsala , Sweden .
- Department of Biotechnology , Chemistry and Pharmacy , Università di Siena , Via A. Moro 2 , 53100 Siena , Italy
| | - Burkhard Zietz
- Department of Chemistry - Ångström Laboratory , Uppsala University , Box 523 , SE75120 Uppsala , Sweden .
| | - Ann Marie Woys
- Department of Chemistry , Argonne-Northwestern Solar Energy Research (ANSER) Center , Northwestern University , Evanston , Illinois 60208-3113 , USA .
| | - Stephen A Miller
- Department of Chemistry , Argonne-Northwestern Solar Energy Research (ANSER) Center , Northwestern University , Evanston , Illinois 60208-3113 , USA .
| | - Michael R Wasielewski
- Department of Chemistry , Argonne-Northwestern Solar Energy Research (ANSER) Center , Northwestern University , Evanston , Illinois 60208-3113 , USA .
| | - Leif Hammarström
- Department of Chemistry - Ångström Laboratory , Uppsala University , Box 523 , SE75120 Uppsala , Sweden .
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13
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Eberhard J, Peuntinger K, Fröhlich R, Guldi DM, Mattay J. Synthesis and Properties of Acridine and Acridinium Dye Functionalized Bis(terpyridine) Ruthenium(II) Complexes. European J Org Chem 2018. [DOI: 10.1002/ejoc.201800257] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Affiliation(s)
- Jens Eberhard
- Organische Chemie I; Fakultät für Chemie; Universität Bielefeld; Universitätsstr. 25 33501 Bielefeld Germany
| | - Katrin Peuntinger
- Physikalische Chemie I; Department of Chemistry and Pharmacy and Interdisciplinary Center for Molecular Materials; Friedrich-Alexander-Universität Erlangen-Nürnberg; Egerlandstr. 3 91058 Erlangen Germany
| | - Roland Fröhlich
- Röntgenstrukturanalyse; Organisch-Chemisches Institut; Westfälische Wilhelms-Universität Münster; Corrensstr. 40 48149 Münster Germany
| | - Dirk M. Guldi
- Physikalische Chemie I; Department of Chemistry and Pharmacy and Interdisciplinary Center for Molecular Materials; Friedrich-Alexander-Universität Erlangen-Nürnberg; Egerlandstr. 3 91058 Erlangen Germany
| | - Jochen Mattay
- Organische Chemie I; Fakultät für Chemie; Universität Bielefeld; Universitätsstr. 25 33501 Bielefeld Germany
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14
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Luo Y, Wächtler M, Barthelmes K, Winter A, Schubert US, Dietzek B. Coexistence of distinct intramolecular electron transfer pathways in polyoxometalate based molecular triads. Phys Chem Chem Phys 2018; 20:11740-11748. [PMID: 29651486 DOI: 10.1039/c8cp01007b] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Polyoxometalate (POM)-associated charge-separated states, formed by the photoinduced oxidation of a covalently attached photosensitizer and reduction of the POM, have attracted much attention due to the remarkable catalytic properties of the reduced POMs. However, short lifetimes of the POM-associated charge-separated state, which in some cases lead to the backward electron transfer being more rapid than the formation of the charge-separated state itself, are generally observed. Recently, we reported on the first example of a relative long-lived (τ = 470 ns) charge-separated state in a Ru(ii) bis(terpyridine)-POM molecular dyad. In this manuscript, further studies on extended molecular structures - two molecular triads - which contain an additional electron donor, phenothiazine (PTZ) or π-extended tetrathiafulvalene (exTTF), are discussed. We show that the excitation of the photosensitizer leads to the population of two distinct MLCT states, which differ in the distribution of excess electron density on the two distinct tpy ligands. These two MLCT states decay separately and, thus, constitute the starting points for distinct intramolecular electron-transfer pathways leading to the simultaneous population of two partially charge-separated states, i.e. PTZ˙+-Ru(tpy)2˙--POM and PTZ-RuIII(tpy)2-POM˙-. These independent decay pathways are unaffected by the choice of the electron donor. Thus, the initial charge distribution within the coordination environment of the photocenter determines the nature of the subsequent (partially) charge separated state that is formed in the triads. These results might open new avenues to design molecular interfaces, in which the directionality of electron transfer can be tuned by the choice of initial excitation.
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Affiliation(s)
- Yusen Luo
- Institute of Physical Chemistry and Abbe Center of Photonics, Friedrich Schiller University Jena, Helmholtzweg 4, 07743, Jena, Germany
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15
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Soupart A, Dixon IM, Alary F, Heully JL. DFT rationalization of the room-temperature luminescence properties of Ru(bpy)
3
2+
and Ru(tpy)
2
2+
: 3MLCT–3MC minimum energy path from NEB calculations and emission spectra from VRES calculations. Theor Chem Acc 2018. [DOI: 10.1007/s00214-018-2216-1] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/17/2022]
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16
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Schneider KRA, Traber P, Reichardt C, Weiss H, Kupfer S, Görls H, Gräfe S, Weigand W, Dietzek B. Unusually Short-Lived Solvent-Dependent Excited State in a Half-Sandwich Ru(II) Complex Induced by Low-Lying 3MC States. J Phys Chem A 2018; 122:1550-1559. [PMID: 29369626 DOI: 10.1021/acs.jpca.7b11470] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
A ruthenium complex with a half-sandwich geometry ([(p-cymene)Ru(Cl)(curcuminoid)]) was synthesized, characterized, and investigated regarding its ultrafast photophysics. These photophysical investigations of the complex revealed a weak and short-lived emission from the initially populated 1MLCT state and solvent-dependent photoinduced dynamics, where the secondarily populated 3MC state is stabilized by nonpolar solvents. Overall the decay of the 3dd-MC state to the ground state is completed within picoseconds. This short excited-state lifetime is in stark contrast to the typically observed long-lived 3MLCT states with lifetimes of nanoseconds or microseconds in unstrained, octahedral ruthenium complexes but is in good agreement with the findings for distorted octahedral complexes. This is pointing to the half-sandwich geometry as a new and easy approach to study these otherwise often concealed dd states.
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Affiliation(s)
- Kilian R A Schneider
- Department Functional Interfaces, Leibniz Institute of Photonic Technology (IPHT) e. V. , Albert-Einstein-Straße 9, 07745 Jena, Germany
| | | | - Christian Reichardt
- Department Functional Interfaces, Leibniz Institute of Photonic Technology (IPHT) e. V. , Albert-Einstein-Straße 9, 07745 Jena, Germany
| | | | | | | | | | | | - Benjamin Dietzek
- Department Functional Interfaces, Leibniz Institute of Photonic Technology (IPHT) e. V. , Albert-Einstein-Straße 9, 07745 Jena, Germany
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17
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Luo Y, Wächtler M, Barthelmes K, Winter A, Schubert US, Dietzek B. Direct detection of the photoinduced charge-separated state in a Ru(ii) bis(terpyridine)-polyoxometalate molecular dyad. Chem Commun (Camb) 2018; 54:2970-2973. [PMID: 29399681 DOI: 10.1039/c7cc09181h] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
Observation of photoinduced intramolecular charge-separation is difficult for photosensitizer-POM dyads because of rapid backward electron transfer. We report here for the first time on a long-lived charge-separated state (τ = 470 ns) observed in a Ru(ii) bis(terpyridine)-based dyad. Charge-separation occurs despite virtually no driving force and the short intrinsic excited-state lifetime of the photosensitizer.
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Affiliation(s)
- Yusen Luo
- Institute of Physical Chemistry and Abbe Center of Photonics, Friedrich Schiller University Jena, Helmholtzweg 4, Jena 07743, Germany and Leibniz Institute of Photonic Technology (IPHT), Albert-Einstein-Straβe 9, Jena 07745, Germany.
| | - Maria Wächtler
- Leibniz Institute of Photonic Technology (IPHT), Albert-Einstein-Straβe 9, Jena 07745, Germany.
| | - Kevin Barthelmes
- Laboratory of Organic and Macromolecular Chemistry (IOMC), Friedrich Schiller University Jena, Humboldtstraβe 10, Jena 07743, Germany and Center for Energy and Environmental Chemistry Jena (CEEC Jena), Friedrich Schiller University Jena, Philosophenweg 7a, Jena 07743, Germany
| | - Andreas Winter
- Laboratory of Organic and Macromolecular Chemistry (IOMC), Friedrich Schiller University Jena, Humboldtstraβe 10, Jena 07743, Germany and Center for Energy and Environmental Chemistry Jena (CEEC Jena), Friedrich Schiller University Jena, Philosophenweg 7a, Jena 07743, Germany
| | - Ulrich S Schubert
- Laboratory of Organic and Macromolecular Chemistry (IOMC), Friedrich Schiller University Jena, Humboldtstraβe 10, Jena 07743, Germany and Center for Energy and Environmental Chemistry Jena (CEEC Jena), Friedrich Schiller University Jena, Philosophenweg 7a, Jena 07743, Germany
| | - Benjamin Dietzek
- Institute of Physical Chemistry and Abbe Center of Photonics, Friedrich Schiller University Jena, Helmholtzweg 4, Jena 07743, Germany and Leibniz Institute of Photonic Technology (IPHT), Albert-Einstein-Straβe 9, Jena 07745, Germany. and Center for Energy and Environmental Chemistry Jena (CEEC Jena), Friedrich Schiller University Jena, Philosophenweg 7a, Jena 07743, Germany
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18
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Cadranel A, Oviedo PS, Pieslinger GE, Yamazaki S, Kleiman VD, Baraldo LM, Guldi DM. Trapping intermediate MLCT states in low-symmetry {Ru(bpy)} complexes. Chem Sci 2017; 8:7434-7442. [PMID: 29163895 PMCID: PMC5674176 DOI: 10.1039/c7sc02670f] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2017] [Accepted: 08/27/2017] [Indexed: 11/21/2022] Open
Abstract
The picosecond excited state dynamics of [Ru(tpm)(bpy)(NCS)]+ (RubNCS+ ) and [Ru(tpm)(bpy)(CN)]+ (RubCN+ ) (tpm = tris(1-pyrazolyl)methane, bpy = 2,2'-bipyridine) have been analyzed by means of transient absorption measurements and spectroelectrochemistry. Emissive 3MLCTs with (GS)HOMO(h+)-(GS)LUMO(e-) configurations are the lowest triplet excited states regardless of whether 387 or 505 nm photoexcitation is used. 387 nm photoexcitation yields, after a few picoseconds, the emissive 3MLCTs. In contrast, 505 nm photoexcitation populates an intermediate excited state that we assign as a 3MLCT state, in which the hole sits in a metal-centered orbital of different symmetry, prior to its conversion to the emissive 3MLCTs. The disparities in terms of electronic configuration between the intermediate and the emissive 3MLCTs have two important consequences. On one hand, both states feature very different fingerprint absorptions in transient absorption measurements. On the other hand, the reconfiguration is impeded by a kinetic barrier. As such, the conversion is followed spectroscopically and kinetically on the 300 ps timescale.
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Affiliation(s)
- Alejandro Cadranel
- Department of Chemistry and Pharmacy , Interdisciplinary Center for Molecular Materials (ICMM) , Friedrich-Alexander-Universität Erlangen-Nürnberg , Egerlandstr. 3 , 91058 Erlangen , Germany . ;
| | - Paola S Oviedo
- Departamento de Química Analítica , Inorgánica y Química Física , INQUIMAE , Facultad de Ciencias Exactas y Naturales , Universidad de Buenos Aires , Ciudad Universitaria , Pabellón 2 , C1428EHA , Buenos Aires , Argentina
| | - German E Pieslinger
- Departamento de Química Analítica , Inorgánica y Química Física , INQUIMAE , Facultad de Ciencias Exactas y Naturales , Universidad de Buenos Aires , Ciudad Universitaria , Pabellón 2 , C1428EHA , Buenos Aires , Argentina
| | - Shiori Yamazaki
- Department of Chemistry , University of Florida , PO BOX 117200 , Gainesville , FL 32611-7200 , USA
| | - Valeria D Kleiman
- Department of Chemistry , University of Florida , PO BOX 117200 , Gainesville , FL 32611-7200 , USA
| | - Luis M Baraldo
- Departamento de Química Analítica , Inorgánica y Química Física , INQUIMAE , Facultad de Ciencias Exactas y Naturales , Universidad de Buenos Aires , Ciudad Universitaria , Pabellón 2 , C1428EHA , Buenos Aires , Argentina
| | - Dirk M Guldi
- Department of Chemistry and Pharmacy , Interdisciplinary Center for Molecular Materials (ICMM) , Friedrich-Alexander-Universität Erlangen-Nürnberg , Egerlandstr. 3 , 91058 Erlangen , Germany . ;
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19
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Ponseca CS, Chábera P, Uhlig J, Persson P, Sundström V. Ultrafast Electron Dynamics in Solar Energy Conversion. Chem Rev 2017; 117:10940-11024. [DOI: 10.1021/acs.chemrev.6b00807] [Citation(s) in RCA: 211] [Impact Index Per Article: 30.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Affiliation(s)
- Carlito S. Ponseca
- Division
of Chemical Physics, Chemical Center, and ‡Theoretical Chemistry Division,
Chemical Center, Lund University, Box 124, Lund SE-221 00, Sweden
| | - Pavel Chábera
- Division
of Chemical Physics, Chemical Center, and ‡Theoretical Chemistry Division,
Chemical Center, Lund University, Box 124, Lund SE-221 00, Sweden
| | - Jens Uhlig
- Division
of Chemical Physics, Chemical Center, and ‡Theoretical Chemistry Division,
Chemical Center, Lund University, Box 124, Lund SE-221 00, Sweden
| | - Petter Persson
- Division
of Chemical Physics, Chemical Center, and ‡Theoretical Chemistry Division,
Chemical Center, Lund University, Box 124, Lund SE-221 00, Sweden
| | - Villy Sundström
- Division
of Chemical Physics, Chemical Center, and ‡Theoretical Chemistry Division,
Chemical Center, Lund University, Box 124, Lund SE-221 00, Sweden
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20
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Morseth ZA, Pho TV, Sheridan MV, Meyer TJ, Schanze KS, Reynolds JR, Papanikolas JM. Interfacial Dynamics within an Organic Chromophore-Based Water Oxidation Molecular Assembly. ACS APPLIED MATERIALS & INTERFACES 2017; 9:16651-16659. [PMID: 28441864 DOI: 10.1021/acsami.7b02713] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
Abstract
Photoinduced electron injection, intra-assembly electron transfer, and back-electron transfer are investigated in a single-site molecular assembly formed by covalently linking a phosphonated terthiophene (T3) chromophore to a Ru(terpyridine)(bipyridine)(L)2+ (L = MeCN or H2O) water oxidation catalyst adsorbed onto a mesoporous metal-oxide (MOx) film. Density functional theory calculations of the T3-trpy-Ru-L assembly indicate that the molecular components are strongly coupled with enhanced low-energy absorptions owing to the presence of an intraligand charge transfer (ILCT) transition between the T3 and trpy moieties. Ultrafast spectroscopy of the MOx//T3-trpy-Ru-L assemblies reveals that excitation of the surface-bound T3 chromophore results in ps-ns electron injection into the metal-oxide conduction band. Electron injection is followed by rapid (<35 ps) intra-assembly electron transfer from the RuII catalyst to regenerate the T3 chromophore with subsequent back-electron transfer on the microsecond time scale.
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Affiliation(s)
- Zachary A Morseth
- Department of Chemistry, University of North Carolina at Chapel Hill , Chapel Hill, North Carolina 27599, United States
| | - Toan V Pho
- School of Chemistry and Biochemistry, School of Materials Science and Engineering, Center for Organic Photonics and Electronics, Georgia Tech Polymer Network, Georgia Institute of Technology , Atlanta, Georgia 30332, United States
| | - Matthew V Sheridan
- Department of Chemistry, University of North Carolina at Chapel Hill , Chapel Hill, North Carolina 27599, United States
| | - Thomas J Meyer
- Department of Chemistry, University of North Carolina at Chapel Hill , Chapel Hill, North Carolina 27599, United States
| | - Kirk S Schanze
- Department of Chemistry, University of Texas at San Antonio , San Antonio, Texas 78249, United States
| | - John R Reynolds
- School of Chemistry and Biochemistry, School of Materials Science and Engineering, Center for Organic Photonics and Electronics, Georgia Tech Polymer Network, Georgia Institute of Technology , Atlanta, Georgia 30332, United States
| | - John M Papanikolas
- Department of Chemistry, University of North Carolina at Chapel Hill , Chapel Hill, North Carolina 27599, United States
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21
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Luo Y, Barthelmes K, Wächtler M, Winter A, Schubert US, Dietzek B. Energy versus Electron Transfer: Controlling the Excitation Transfer in Molecular Triads. Chemistry 2017; 23:4917-4922. [PMID: 28198051 DOI: 10.1002/chem.201700413] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/27/2017] [Indexed: 01/23/2023]
Abstract
The photochemistry of RuII coordination compounds is generally discussed to originate from the lowest lying triplet metal-to-ligand charge-transfer state (3 MLCT). However, when heteroleptic complexes are considered, for example, in the design of molecular triads for efficient photoinduced charge separation, a complex structure of 1 MLCT states, which can be populated in a rather narrow spectral window (typically around 450 nm) is to be considered. In this contribution we show that the localization of MLCT excited states on different ligands can affect the following ps to ns decay pathways to an extent that by tuning the excitation wavelength, intermolecular energy transfer from a RuII -terpyridine unit to a fullerene acceptor can be favored over electron transfer within the molecular triad. These results might have important implications for the design of molecular dyads, triads, pentads and so forth with respect to a specifically targeted response of these complexes to photoexcitation.
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Affiliation(s)
- Yusen Luo
- Institute of Physical Chemistry and Abbe Center of Photonics, Friedrich-Schiller-University Jena, Helmholtzweg 4, 07743, Jena, Germany.,Leibniz Institute of Photonic Technology (IPHT), Albert-Einstein-Strasse 9, 07745, Jena, Germany
| | - Kevin Barthelmes
- Jena Center for Soft Matter (JCSM), Friedrich-Schiller-University Jena, Philosophenweg 7, 07743, Jena, Germany.,Laboratory of Organic and Macromolecular Chemistry (IOMC), Friedrich-Schiller-University Jena, Humboldtstrasse 10, 07743, Jena, Germany
| | - Maria Wächtler
- Leibniz Institute of Photonic Technology (IPHT), Albert-Einstein-Strasse 9, 07745, Jena, Germany
| | - Andreas Winter
- Jena Center for Soft Matter (JCSM), Friedrich-Schiller-University Jena, Philosophenweg 7, 07743, Jena, Germany.,Laboratory of Organic and Macromolecular Chemistry (IOMC), Friedrich-Schiller-University Jena, Humboldtstrasse 10, 07743, Jena, Germany
| | - Ulrich S Schubert
- Jena Center for Soft Matter (JCSM), Friedrich-Schiller-University Jena, Philosophenweg 7, 07743, Jena, Germany.,Laboratory of Organic and Macromolecular Chemistry (IOMC), Friedrich-Schiller-University Jena, Humboldtstrasse 10, 07743, Jena, Germany
| | - Benjamin Dietzek
- Institute of Physical Chemistry and Abbe Center of Photonics, Friedrich-Schiller-University Jena, Helmholtzweg 4, 07743, Jena, Germany.,Leibniz Institute of Photonic Technology (IPHT), Albert-Einstein-Strasse 9, 07745, Jena, Germany.,Jena Center for Soft Matter (JCSM), Friedrich-Schiller-University Jena, Philosophenweg 7, 07743, Jena, Germany
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22
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Fatur SM, Shepard SG, Higgins RF, Shores MP, Damrauer NH. A Synthetically Tunable System To Control MLCT Excited-State Lifetimes and Spin States in Iron(II) Polypyridines. J Am Chem Soc 2017; 139:4493-4505. [DOI: 10.1021/jacs.7b00700] [Citation(s) in RCA: 75] [Impact Index Per Article: 10.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Steven M. Fatur
- Department
of Chemistry and Biochemistry, University of Colorado Boulder, Boulder, Colorado 80309, United States
| | - Samuel G. Shepard
- Department
of Chemistry and Biochemistry, University of Colorado Boulder, Boulder, Colorado 80309, United States
| | - Robert F. Higgins
- Department
of Chemistry, Colorado State University, Fort Collins, Colorado 80523, United States
| | - Matthew P. Shores
- Department
of Chemistry, Colorado State University, Fort Collins, Colorado 80523, United States
| | - Niels H. Damrauer
- Department
of Chemistry and Biochemistry, University of Colorado Boulder, Boulder, Colorado 80309, United States
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23
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Cadranel A, Tate JE, Oviedo PS, Yamazaki S, Hodak JH, Baraldo LM, Kleiman VD. Distant ultrafast energy transfer in a trimetallic {Ru-Ru-Cr} complex facilitated by hole delocalization. Phys Chem Chem Phys 2017; 19:2882-2893. [PMID: 28074958 DOI: 10.1039/c6cp06562g] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Abstract
Multi-metallic complexes based on {Ru-Cr}, {Ru-Ru} and {Ru-Ru-Cr} fragments are investigated for their light-harvesting and long-range energy transfer properties. We report the synthesis and characterization of [Ru(tpy)(bpy)(μ-CN)Ru(py)4Cl]2+ and [Ru(tpy)(bpy)(μ-CN)Ru(py)4(μ-NC)Cr(CN)5]. The intercalation of {RuII(py)4} linked by cyanide bridges between {Ru(tpy)(bpy)} and {Cr(CN)5} results in efficient, distant energy transfer followed by emission from the Cr moiety. Characterization of the energy transfer process based on photophysical and ultrafast time-resolved absorption suggests the delocalization of holes in the excited state, providing a pathway for energy transfer between the end moieties. The proposed mechanism opens the door to utilize this family of complexes as an appealing platform for the design of antenna compounds as the properties of the fragments could be tuned independently.
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Affiliation(s)
- Alejandro Cadranel
- Departamento de Química Analítica, Inorgánica y Química Física, INQUIMAE, Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires, Pabellón 2, Ciudad Universitaria, Buenos Aires, C1428EHA, Argentina.
| | - Jaired E Tate
- Department of Chemistry, University of Florida, PO BOX 117200, Gainesville, FL 32611-7200, USA.
| | - Paola S Oviedo
- Departamento de Química Analítica, Inorgánica y Química Física, INQUIMAE, Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires, Pabellón 2, Ciudad Universitaria, Buenos Aires, C1428EHA, Argentina.
| | - Shiori Yamazaki
- Department of Chemistry, University of Florida, PO BOX 117200, Gainesville, FL 32611-7200, USA.
| | - José H Hodak
- Departamento de Química Analítica, Inorgánica y Química Física, INQUIMAE, Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires, Pabellón 2, Ciudad Universitaria, Buenos Aires, C1428EHA, Argentina.
| | - Luis M Baraldo
- Departamento de Química Analítica, Inorgánica y Química Física, INQUIMAE, Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires, Pabellón 2, Ciudad Universitaria, Buenos Aires, C1428EHA, Argentina.
| | - Valeria D Kleiman
- Department of Chemistry, University of Florida, PO BOX 117200, Gainesville, FL 32611-7200, USA.
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24
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Liu Y, Persson P, Sundström V, Wärnmark K. Fe N-Heterocyclic Carbene Complexes as Promising Photosensitizers. Acc Chem Res 2016; 49:1477-85. [PMID: 27455191 DOI: 10.1021/acs.accounts.6b00186] [Citation(s) in RCA: 162] [Impact Index Per Article: 20.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
The photophysics and photochemistry of transition metal complexes (TMCs) has long been a hot field of interdisciplinary research. Rich metal-based redox processes, together with a high variety in electronic configurations and excited-state dynamics, have rendered TMCs excellent candidates for interconversion between light, chemical, and electrical energies in intramolecular, supramolecular, and interfacial arrangements. In specific applications such as photocatalytic organic synthesis, photoelectrochemical cells, and light-driven supramolecular motors, light absorption by a TMC-based photosensitizer and subsequent excited-state energy or electron transfer constitute essential steps. In this context, TMCs based on rare and expensive metals, such as ruthenium and iridium, are frequently employed as photosensitizers, which is obviously not ideal for large-scale implementation. In the search for abundant and environmentally benign solutions, six-coordinate Fe(II) complexes (Fe(II)L6) have been widely considered as highly desirable alternatives. However, not much success has been achieved due to the extremely short-lived triplet metal-to-ligand charge transfer ((3)MLCT) excited state that is deactivated by low-lying metal-centered (MC) states on a 100 fs time scale. A fundamental strategy to design useful Fe-based photosensitizers is thus to destabilize the MC states relative to the (3)MLCT state by increasing the ligand field strength, with special focus on making eg σ* orbitals on the Fe center energetically less accessible. Previous efforts to directly transplant successful strategies from Ru(II)L6 complexes unfortunately met with limited success in this regard, despite their close chemical kinship. In this Account, we summarize recent promising results from our and other groups in utilizing strongly σ-donating N-heterocyclic carbene (NHC) ligands to make strong-field Fe(II)L6 complexes with significantly extended (3)MLCT lifetimes. Already some of the first homoleptic bis(tridentate) complexes incorporating (CNHC^Npyridine^CNHC)-type ligands gratifyingly resulted in extension of the (3)MLCT lifetime by more than 2 orders of magnitude compared to the parental [Fe(tpy)2](2+) (tpy = 2,2':6',2″-terpyridine) complex. Quantum chemical (QC) studies also revealed that the (3)MC instead of the (5)MC state likely dictates the deactivation of the (3)MLCT state, a behavior distinct from traditional Fe(II)L6 complexes but rather resembling Ru analogues. A heteroleptic Fe(II) NHC complex featuring mesoionic bis(1,2,3-triazol-5-ylidene) (btz) ligands also delivered a 100-fold elongation of the (3)MLCT lifetime relative to its parental [Fe(bpy)3](2+) (bpy = 2,2'-bipyridine) complex. Again, a Ru-like deactivation mechanism of the (3)MLCT state was indicated by QC studies. With a COOH-functionalized homoleptic complex, a record (3)MLCT lifetime of 37 ps was recently observed on an Al2O3 nanofilm. As a proof of concept, it was further demonstrated that the significant improvement in the (3)MLCT lifetime indeed benefits efficient light harvesting with Fe(II) NHC complexes. For the first time, close-to-unity electron injection from the lowest-energy (3)MLCT state to a TiO2 nanofilm was achieved by a stable Fe(II) complex. This is in complete contrast to conventional Fe(II)L6-derived photosensitizers that could only make use of high-energy photons. These exciting results significantly broaden the understanding of the fundamental photophysics and photochemistry of d(6) Fe(II) complexes. They also open up new possibilities to develop solar energy-converting materials based on this abundant, inexpensive, and intrinsically nontoxic element.
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Affiliation(s)
- Yizhu Liu
- Centre
for Analysis and Synthesis, Lund University, Box 124, 22100 Lund, Sweden
- Department
of Chemical Physics, Lund University, Box 124, 22100 Lund, Sweden
| | - Petter Persson
- Theoretical
Chemistry Division, Lund University, Box 124, 22100 Lund, Sweden
| | - Villy Sundström
- Department
of Chemical Physics, Lund University, Box 124, 22100 Lund, Sweden
| | - Kenneth Wärnmark
- Centre
for Analysis and Synthesis, Lund University, Box 124, 22100 Lund, Sweden
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Sun Q, Dereka B, Vauthey E, Lawson Daku LM, Hauser A. Ultrafast transient IR spectroscopy and DFT calculations of ruthenium(ii) polypyridyl complexes. Chem Sci 2016; 8:223-230. [PMID: 28451169 PMCID: PMC5308284 DOI: 10.1039/c6sc01220e] [Citation(s) in RCA: 49] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/17/2016] [Accepted: 08/10/2016] [Indexed: 12/23/2022] Open
Abstract
Ultrafast time-resolved infrared spectroscopy of [Ru(bpy)3]2+ (bpy = 2,2'-bipyridine), [Ru(mbpy)3]2+ (mbpy = 6-methyl-2,2'-bipyridine) and [Ru(mphen)3]2+ (mphen = 2-methyl-1,10'-phenanthroline) in deuterated acetonitrile serves to elucidate the evolution of the system following pulsed excitation into the 1MLCT band at 400 nm. While for [Ru(bpy)3]2+ no intermediate state can be evidenced for the relaxation of the corresponding 3MLCT state back to the ground state, for [Ru(mbpy)3]2+ and [Ru(mphen)3]2+ an intermediate state with a lifetime of about 400 ps is observed. The species associated IR difference spectra of this state are in good agreement with the calculated difference spectra of the lowest energy 3dd state using DFT. The calculated potential energy curves for all the complexes in the triplet manifold along the metal-ligand distance show that for [Ru(bpy)3]2+ the 3dd state is at a higher energy than the 3MLCT state and that there is a substantial barrier between the two minima. For [Ru(mbpy)3]2+ and [Ru(mphen)3]2+, the 3dd state is at a lower energy than the 3MLCT state.
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Affiliation(s)
- Qinchao Sun
- Département de Chimie Physique , Université de Genève , 30 Quai Ernest-Ansermet , 1211 Genève , Switzerland .
| | - Bogdan Dereka
- Département de Chimie Physique , Université de Genève , 30 Quai Ernest-Ansermet , 1211 Genève , Switzerland .
| | - Eric Vauthey
- Département de Chimie Physique , Université de Genève , 30 Quai Ernest-Ansermet , 1211 Genève , Switzerland .
| | - Latévi M Lawson Daku
- Département de Chimie Physique , Université de Genève , 30 Quai Ernest-Ansermet , 1211 Genève , Switzerland .
| | - Andreas Hauser
- Département de Chimie Physique , Université de Genève , 30 Quai Ernest-Ansermet , 1211 Genève , Switzerland .
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26
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Schlotthauer T, Suchland B, Görls H, Parada GA, Hammarström L, Schubert US, Jäger M. Aryl-Decorated RuII Polypyridyl-type Photosensitizer Approaching NIR Emission with Microsecond Excited State Lifetimes. Inorg Chem 2016; 55:5405-16. [DOI: 10.1021/acs.inorgchem.6b00420] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
Affiliation(s)
- Tina Schlotthauer
- Laboratory
of Organic and Macromolecular Chemistry (IOMC), Friedrich Schiller University Jena, Humboldtstraße 10, 07743 Jena, Germany
| | - Benedikt Suchland
- Laboratory
of Organic and Macromolecular Chemistry (IOMC), Friedrich Schiller University Jena, Humboldtstraße 10, 07743 Jena, Germany
| | - Helmar Görls
- Laboratory
of Inorganic and Analytical Chemistry, Friedrich Schiller University Jena, Lessingstraße 8, 07743 Jena, Germany
| | - Giovanny A. Parada
- Department
of Chemistry - Ångström Laboratory, Uppsala University, Box 523, SE-75120 Uppsala, Sweden
| | - Leif Hammarström
- Department
of Chemistry - Ångström Laboratory, Uppsala University, Box 523, SE-75120 Uppsala, Sweden
| | - Ulrich S. Schubert
- Laboratory
of Organic and Macromolecular Chemistry (IOMC), Friedrich Schiller University Jena, Humboldtstraße 10, 07743 Jena, Germany
- Center
for Energy and Environmental Chemistry Jena (CEEC Jena), Friedrich Schiller University Jena, Philosophenweg 7a, 07743 Jena, Germany
| | - Michael Jäger
- Laboratory
of Organic and Macromolecular Chemistry (IOMC), Friedrich Schiller University Jena, Humboldtstraße 10, 07743 Jena, Germany
- Center
for Energy and Environmental Chemistry Jena (CEEC Jena), Friedrich Schiller University Jena, Philosophenweg 7a, 07743 Jena, Germany
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27
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Barthelmes K, Jäger M, Kübel J, Friebe C, Winter A, Wächtler M, Dietzek B, Schubert US. Efficient Energy Transfer and Metal Coupling in Cyanide-Bridged Heterodinuclear Complexes Based on (Bipyridine)(terpyridine)ruthenium(II) and (Phenylpyridine)iridium(III) Complexes. Inorg Chem 2016; 55:5152-67. [DOI: 10.1021/acs.inorgchem.5b02919] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Affiliation(s)
- Kevin Barthelmes
- Laboratory
of Organic and Macromolecular Chemistry, Friedrich Schiller University Jena, Humboldtstraße 10, 07743 Jena, Germany
- Center
for Energy and Environmental Chemistry, Friedrich Schiller University Jena, Philosophenweg 7a, 07743 Jena, Germany
| | - Michael Jäger
- Laboratory
of Organic and Macromolecular Chemistry, Friedrich Schiller University Jena, Humboldtstraße 10, 07743 Jena, Germany
- Center
for Energy and Environmental Chemistry, Friedrich Schiller University Jena, Philosophenweg 7a, 07743 Jena, Germany
| | - Joachim Kübel
- Leibniz Institute of Photonic Technology, Albert-Einstein-Straße 9, 07745 Jena, Germany
- Institute
of Physical Chemistry and Abbe Center of Photonics, Friedrich Schiller University Jena, Helmholtzweg 4, 07743 Jena, Germany
| | - Christian Friebe
- Laboratory
of Organic and Macromolecular Chemistry, Friedrich Schiller University Jena, Humboldtstraße 10, 07743 Jena, Germany
- Center
for Energy and Environmental Chemistry, Friedrich Schiller University Jena, Philosophenweg 7a, 07743 Jena, Germany
| | - Andreas Winter
- Laboratory
of Organic and Macromolecular Chemistry, Friedrich Schiller University Jena, Humboldtstraße 10, 07743 Jena, Germany
- Center
for Energy and Environmental Chemistry, Friedrich Schiller University Jena, Philosophenweg 7a, 07743 Jena, Germany
| | - Maria Wächtler
- Leibniz Institute of Photonic Technology, Albert-Einstein-Straße 9, 07745 Jena, Germany
| | - Benjamin Dietzek
- Center
for Energy and Environmental Chemistry, Friedrich Schiller University Jena, Philosophenweg 7a, 07743 Jena, Germany
- Leibniz Institute of Photonic Technology, Albert-Einstein-Straße 9, 07745 Jena, Germany
- Institute
of Physical Chemistry and Abbe Center of Photonics, Friedrich Schiller University Jena, Helmholtzweg 4, 07743 Jena, Germany
| | - Ulrich S. Schubert
- Laboratory
of Organic and Macromolecular Chemistry, Friedrich Schiller University Jena, Humboldtstraße 10, 07743 Jena, Germany
- Center
for Energy and Environmental Chemistry, Friedrich Schiller University Jena, Philosophenweg 7a, 07743 Jena, Germany
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28
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Zigler DF, Morseth ZA, Wang L, Ashford DL, Brennaman MK, Grumstrup EM, Brigham EC, Gish MK, Dillon RJ, Alibabaei L, Meyer GJ, Meyer TJ, Papanikolas JM. Disentangling the Physical Processes Responsible for the Kinetic Complexity in Interfacial Electron Transfer of Excited Ru(II) Polypyridyl Dyes on TiO2. J Am Chem Soc 2016; 138:4426-38. [DOI: 10.1021/jacs.5b12996] [Citation(s) in RCA: 72] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- David F. Zigler
- Caudill, Kenan, and Murray
Laboratories, Department of Chemistry, University of North Carolina at Chapel Hill, Campus
Box 3290, Chapel Hill, North Carolina 27599, United States
| | - Zachary A. Morseth
- Caudill, Kenan, and Murray
Laboratories, Department of Chemistry, University of North Carolina at Chapel Hill, Campus
Box 3290, Chapel Hill, North Carolina 27599, United States
| | - Li Wang
- Caudill, Kenan, and Murray
Laboratories, Department of Chemistry, University of North Carolina at Chapel Hill, Campus
Box 3290, Chapel Hill, North Carolina 27599, United States
| | - Dennis L. Ashford
- Caudill, Kenan, and Murray
Laboratories, Department of Chemistry, University of North Carolina at Chapel Hill, Campus
Box 3290, Chapel Hill, North Carolina 27599, United States
| | - M. Kyle Brennaman
- Caudill, Kenan, and Murray
Laboratories, Department of Chemistry, University of North Carolina at Chapel Hill, Campus
Box 3290, Chapel Hill, North Carolina 27599, United States
| | - Erik M. Grumstrup
- Caudill, Kenan, and Murray
Laboratories, Department of Chemistry, University of North Carolina at Chapel Hill, Campus
Box 3290, Chapel Hill, North Carolina 27599, United States
| | - Erinn C. Brigham
- Caudill, Kenan, and Murray
Laboratories, Department of Chemistry, University of North Carolina at Chapel Hill, Campus
Box 3290, Chapel Hill, North Carolina 27599, United States
| | - Melissa K. Gish
- Caudill, Kenan, and Murray
Laboratories, Department of Chemistry, University of North Carolina at Chapel Hill, Campus
Box 3290, Chapel Hill, North Carolina 27599, United States
| | - Robert J. Dillon
- Caudill, Kenan, and Murray
Laboratories, Department of Chemistry, University of North Carolina at Chapel Hill, Campus
Box 3290, Chapel Hill, North Carolina 27599, United States
| | - Leila Alibabaei
- Caudill, Kenan, and Murray
Laboratories, Department of Chemistry, University of North Carolina at Chapel Hill, Campus
Box 3290, Chapel Hill, North Carolina 27599, United States
| | - Gerald J. Meyer
- Caudill, Kenan, and Murray
Laboratories, Department of Chemistry, University of North Carolina at Chapel Hill, Campus
Box 3290, Chapel Hill, North Carolina 27599, United States
| | - Thomas J. Meyer
- Caudill, Kenan, and Murray
Laboratories, Department of Chemistry, University of North Carolina at Chapel Hill, Campus
Box 3290, Chapel Hill, North Carolina 27599, United States
| | - John M. Papanikolas
- Caudill, Kenan, and Murray
Laboratories, Department of Chemistry, University of North Carolina at Chapel Hill, Campus
Box 3290, Chapel Hill, North Carolina 27599, United States
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29
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Shepard SG, Fatur SM, Rappé AK, Damrauer NH. Highly Strained Iron(II) Polypyridines: Exploiting the Quintet Manifold To Extend the Lifetime of MLCT Excited States. J Am Chem Soc 2016; 138:2949-52. [DOI: 10.1021/jacs.5b13524] [Citation(s) in RCA: 57] [Impact Index Per Article: 7.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Samuel G. Shepard
- Department
of Chemistry and Biochemistry, University of Colorado Boulder, Boulder, Colorado 80309, United States
| | - Steven M. Fatur
- Department
of Chemistry and Biochemistry, University of Colorado Boulder, Boulder, Colorado 80309, United States
| | - Anthony K. Rappé
- Department
of Chemistry, Colorado State University, Fort Collins, Colorado 80523, United States
| | - Niels H. Damrauer
- Department
of Chemistry and Biochemistry, University of Colorado Boulder, Boulder, Colorado 80309, United States
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30
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Cadranel A, Pieslinger GE, Tongying P, Kuno MK, Baraldo LM, Hodak JH. Spectroscopic signatures of ligand field states in {Ru(II)(imine)} complexes. Dalton Trans 2016; 45:5464-75. [PMID: 26841245 DOI: 10.1039/c5dt04332h] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
Ligand field (LF) states have been present in discussions on the photophysics and photochemistry of ruthenium-iminic chromophores for decades, although there is very little documented direct evidence of them. We studied the picosecond transient absorption (TA) spectroscopy of four {Ru(II)(imine)} complexes that respond to the formula trans-[Ru(L)4(X)2], where L is either pyridine (py) or 4-methoxypyridine (MeOpy) and X is either cyanide or thiocyanate. Dicyano compounds behave as most ruthenium polypyridines and their LF states remain silent. In contrast, in the dithiocyanate complexes we found clear spectroscopic evidence of the participation of LF states in the MLCT decay pathway. These states are of donor and acceptor character simultaneously and this is manifested in the presence of MLCT and LMCT transient absorption bands of similar energy. Spectroelectrochemical techniques supported the interpretation of the absorption features of MLCT states, and DFT methods helped to assign their spectroscopic signatures and provided strong evidence on the nature of LF states.
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Affiliation(s)
- Alejandro Cadranel
- Departamento de Química Analítica, Inorgánica y Química Física, INQUIMAE, Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires, Pabellón 2, Ciudad Universitaria, C1428EHA, Buenos Aires, Argentina.
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31
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Wächtler M, Kübel J, Barthelmes K, Winter A, Schmiedel A, Pascher T, Lambert C, Schubert US, Dietzek B. Energy transfer and formation of long-lived 3MLCT states in multimetallic complexes with extended highly conjugated bis-terpyridyl ligands. Phys Chem Chem Phys 2016; 18:2350-60. [DOI: 10.1039/c5cp04447b] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
Abstract
Multimetallic complexes with extended conjugated ligands show efficient energy transfer to the lowest excited states and prolonged Fe(ii) 3MLCT lifetimes.
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Affiliation(s)
- Maria Wächtler
- Leibniz Institute of Photonic Technology e.V
- 07745 Jena
- Germany
| | - Joachim Kübel
- Leibniz Institute of Photonic Technology e.V
- 07745 Jena
- Germany
- Institute of Physical Chemistry and Abbe Center of Photonics
- Friedrich Schiller University Jena
| | - Kevin Barthelmes
- Laboratory of Organic and Macromolecular Chemistry (IOMC)
- Friedrich Schiller University Jena
- 07743 Jena
- Germany
- Jena Center for Soft Matter (JCSM)
| | - Andreas Winter
- Laboratory of Organic and Macromolecular Chemistry (IOMC)
- Friedrich Schiller University Jena
- 07743 Jena
- Germany
- Jena Center for Soft Matter (JCSM)
| | - Alexander Schmiedel
- Institut für Organische Chemie
- Universität Würzburg
- Wilhelm Conrad Röntgen Research Center for Complex Material Systems
- Center for Nanosystems Chemistry
- 97074 Würzburg
| | | | - Christoph Lambert
- Institut für Organische Chemie
- Universität Würzburg
- Wilhelm Conrad Röntgen Research Center for Complex Material Systems
- Center for Nanosystems Chemistry
- 97074 Würzburg
| | - Ulrich S. Schubert
- Laboratory of Organic and Macromolecular Chemistry (IOMC)
- Friedrich Schiller University Jena
- 07743 Jena
- Germany
- Jena Center for Soft Matter (JCSM)
| | - Benjamin Dietzek
- Leibniz Institute of Photonic Technology e.V
- 07745 Jena
- Germany
- Institute of Physical Chemistry and Abbe Center of Photonics
- Friedrich Schiller University Jena
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32
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Brown AM, McCusker CE, McCusker JK. Spectroelectrochemical identification of charge-transfer excited states in transition metal-based polypyridyl complexes. Dalton Trans 2015; 43:17635-46. [PMID: 25321952 DOI: 10.1039/c4dt02849j] [Citation(s) in RCA: 70] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Identification of transient species is a necessary part of delineating the kinetics and mechanisms associated with chemical dynamics; when dealing with photo-induced processes, this can be an exceptionally challenging task due to the fact that spectra associated with excited state(s) sampled over the course of a photochemical event often cannot be uniquely identified nor readily calculated. Using Group 8 complexes of the general form [M(terpy)2](2+) and [M(bpy)3](2+) as a platform (where terpy is 2,2':6',2''-terpyridine and bpy is 2,2'-bipyridine), we demonstrate how spectroelectrochemical measurements can serve as an effective tool for identifying spectroscopic signatures of charge-transfer excited states of transition metal-based chromophores. Formulating the metal-to-ligand charge-transfer (MLCT) excited state(s) as M(3+)-L(-), the extent to which a linear combination of the spectra of the oxidized and reduced forms of the parent complexes can be used to simulate the characteristic absorptions of MLCT-based transient species is examined. Quantitative agreement is determined to be essentially unachievable due to the fact that certain transitions associated with the optically prepared excited states are either overcompensated for in the spectroelectrochemical data, or simply cannot be replicated through electrochemical means. Despite this limitation, it is shown through several illustrative examples that this approach can still be extremely useful as a qualitative if not semi-quantitative guide for interpreting time-resolved electronic absorption data of charge-transfer compounds, particularly in the ultrafast time domain.
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Affiliation(s)
- Allison M Brown
- Contribution from the Department of Chemistry, Michigan State University, 578 South Shaw Lane, East Lansing, MI 48824, USA.
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Stark CW, Schreier WJ, Lucon J, Edwards E, Douglas T, Kohler B. Interligand Electron Transfer in Heteroleptic Ruthenium(II) Complexes Occurs on Multiple Time Scales. J Phys Chem A 2015; 119:4813-24. [DOI: 10.1021/acs.jpca.5b01770] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Charles W. Stark
- Department of Chemistry and
Biochemistry, Montana State University, Bozeman, Montana 59717, United States
| | - Wolfgang J. Schreier
- Department of Chemistry and
Biochemistry, Montana State University, Bozeman, Montana 59717, United States
| | - Janice Lucon
- Department of Chemistry and
Biochemistry, Montana State University, Bozeman, Montana 59717, United States
| | - Ethan Edwards
- Department of Chemistry and
Biochemistry, Montana State University, Bozeman, Montana 59717, United States
| | - Trevor Douglas
- Department of Chemistry and
Biochemistry, Montana State University, Bozeman, Montana 59717, United States
| | - Bern Kohler
- Department of Chemistry and
Biochemistry, Montana State University, Bozeman, Montana 59717, United States
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Preiß J, Jäger M, Rau S, Dietzek B, Popp J, Martínez T, Presselt M. How Does Peripheral Functionalization of Ruthenium(II)-Terpyridine Complexes Affect Spatial Charge Redistribution after Photoexcitation at the Franck-Condon Point? Chemphyschem 2015; 16:1395-404. [DOI: 10.1002/cphc.201500223] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/16/2015] [Indexed: 02/06/2023]
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35
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Schindler J, Kupfer S, Wächtler M, Guthmuller J, Rau S, Dietzek B. Photophysics of a Ruthenium 4H-Imidazole Panchromatic Dye in Interaction with Titanium Dioxide. Chemphyschem 2015; 16:1061-70. [DOI: 10.1002/cphc.201402856] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/02/2014] [Indexed: 11/11/2022]
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Kowacs T, Pan Q, Lang P, O'Reilly L, Rau S, Browne WR, Pryce MT, Huijser A, Vos JG. Supramolecular bimetallic assemblies for photocatalytic hydrogen generation from water. Faraday Discuss 2015; 185:143-70. [DOI: 10.1039/c5fd00068h] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
A series of supramolecular assemblies of the type [Ru(L-L)2(L′-L)MX2)]n+ are reported where L-L is 2,2′-bipyridine (bipy), 4,4′-di-tetra-butyl-bipyridine (tbbipy) or 4,4′-diethoxycarbonyl-2,2′-bipyridine (dceb), L-L′ is tetrapyrido[3,2-a:2′,3′-c:3′′,2′′-h:2′′′,3′′′-j]phenazine (tpphz), 2,2′:5′,2′′-terpyridine (2,5-bpp), 2,2′:6′,2′′-terpyridine, (2,6-bpp), 2,5-di(pyridine-2-yl)pyrazine (2,5-dpp) or 2,3-di(pyridine-2-yl)pyrazine (2,3-dpp), and MX2 is PdCl2, PtCl2 or PtI2. The photocatalytic behaviour with respect to hydrogen generation of these compounds and their ultrafast photophysical properties are discussed as a function of the nature of the peripheral ligands, the bridging ligands and the catalytic centre. The results obtained show how differences in the chemical composition of the photocatalysts can affect intramolecular photoinduced electron transfer processes and the overall photocatalytic efficiency.
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Affiliation(s)
- Tanja Kowacs
- Institut für Anorganische Chemie I
- Universität Ulm
- 89081 Ulm
- Germany
| | - Qing Pan
- Optical Sciences group
- MESA+ Institute for Nanotechnology
- University of Twente
- Enschede
- The Netherlands
| | - Philipp Lang
- Institut für Anorganische Chemie I
- Universität Ulm
- 89081 Ulm
- Germany
| | - Laura O'Reilly
- SRC for Solar Energy Conversion
- School of Chemical Sciences
- Dublin City University
- Dublin 9
- Ireland
| | - Sven Rau
- Institut für Anorganische Chemie I
- Universität Ulm
- 89081 Ulm
- Germany
| | - Wesley R. Browne
- Stratingh Institute for Chemistry
- Faculty of Mathematics and Natural Sciences
- University of Groningen
- Groningen
- The Netherlands
| | - Mary T. Pryce
- SRC for Solar Energy Conversion
- School of Chemical Sciences
- Dublin City University
- Dublin 9
- Ireland
| | - Annemarie Huijser
- Optical Sciences group
- MESA+ Institute for Nanotechnology
- University of Twente
- Enschede
- The Netherlands
| | - Johannes G. Vos
- SRC for Solar Energy Conversion
- School of Chemical Sciences
- Dublin City University
- Dublin 9
- Ireland
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37
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Sun Q, Mosquera-Vazquez S, Suffren Y, Hankache J, Amstutz N, Lawson Daku LM, Vauthey E, Hauser A. On the role of ligand-field states for the photophysical properties of ruthenium(II) polypyridyl complexes. Coord Chem Rev 2015. [DOI: 10.1016/j.ccr.2014.07.004] [Citation(s) in RCA: 71] [Impact Index Per Article: 7.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
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38
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Liu Y, Kjaer KS, Fredin LA, Chábera P, Harlang T, Canton SE, Lidin S, Zhang J, Lomoth R, Bergquist KE, Persson P, Wärnmark K, Sundström V. A Heteroleptic Ferrous Complex with Mesoionic Bis(1,2,3-triazol-5-ylidene) Ligands: Taming the MLCT Excited State of Iron(II). Chemistry 2014; 21:3628-39. [DOI: 10.1002/chem.201405184] [Citation(s) in RCA: 114] [Impact Index Per Article: 11.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/08/2014] [Indexed: 11/08/2022]
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Spettel KE, Damrauer NH. Synthesis, electrochemical characterization, and photophysical studies of structurally tuned aryl-substituted terpyridyl ruthenium(II) complexes. J Phys Chem A 2014; 118:10649-62. [PMID: 25182073 DOI: 10.1021/jp508145w] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
Synthesis, electrochemical potentials, static emission, and temperature-dependent excited-state lifetimes of several 4'-aryl-substituted terpyridyl complexes of ruthenium(II) are reported. Synthetic tuning is explored within three conceptual series of complexes. The first series explores the impact of introducing a strong σ-donating 4,4',4″-tri-tert-butyl-2,2':6',2″-terpyridine (tbtpy) opposite to an arylated terpyridine ligand 4'-(4-methylphenyl)-2,2':6',2″-terpyridine (ttpy). It is found that (3)MLCT (triplet metal-to-ligand charge-transfer state) stabilization concomitant with (3)MC (triplet metal-centered state) destabilization in the heteroleptic parent complex [Ru(ttpy)(tbtpy)](2+) leads to an extended excited-state lifetime relative to the structurally related bis-homoleptic species [Ru(ttpy)2](2+). The second series explores the impact of introducing a carboxylic acid or a methyl ester moiety at the para-position of the arylterpyridyl ligand (R1 = R2 = H) within heteroleptic complexes as a platform for future semiconductor attachment studies. This substitution leads to further lifetime enhancements, understood as arising from (3)MLCT stabilization. Such complexes are referred to as [Ru(1)(tbtpy)](2+) (for the acid at R3) and [Ru(1')(tbtpy)](2+) (for the ester at R3). In the final series, methyl substituents are sequentially added at the R1 and R2 positions for both the acid ([Ru(2)(tbtpy)](2+) and [Ru(3)(tbtpy)](2+)) and ester ([Ru(2')(tbtpy)](2+) and [Ru(3')(tbtpy)](2+)) analogues to eventually explore dynamical electron transfer coupling at dye/semiconductor interfaces. In these complexes, sequential addition of steric bulk decreases excited state lifetimes. This can be understood to arise primarily from the increase of the (3)MLCT level, as excited-state electron delocalization is limited by inter-ring twisting in the lower-energy arylated ligand. The introduction of a dimethylated sterically encumbered ligand lead to a notable 14-fold increase in knr from [Ru(1')(tbtpy)](2+) to [Ru(3')(tbtpy)](2+) (or [Ru(1)(tbtpy)](2+) to [Ru(3)(tbtpy)](2+)).
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Affiliation(s)
- Karen E Spettel
- Department of Chemistry and Biochemistry, University of Colorado-Boulder , Boulder, Colorado 80309, United States
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40
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Pal AK, Serroni S, Zaccheroni N, Campagna S, Hanan GS. Near infra-red emitting Ru(ii) complexes of tridentate ligands: electrochemical and photophysical consequences of a strong donor ligand with large bite angles. Chem Sci 2014. [DOI: 10.1039/c4sc01604a] [Citation(s) in RCA: 48] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022] Open
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41
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Breul AM, Kübel J, Häupler B, Friebe C, Hager MD, Winter A, Dietzek B, Schubert US. Synthesis and Characterization of Poly(phenylacetylene)s with Ru(II)Bis-Terpyridine Complexes in the Side-Chain. Macromol Rapid Commun 2014; 35:747-51. [DOI: 10.1002/marc.201300806] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/27/2013] [Revised: 12/02/2013] [Indexed: 11/06/2022]
Affiliation(s)
- Alexander M. Breul
- Laboratory of Organic and Macromolecular Chemistry (IOMC), Friedrich Schiller University Jena; Humboldtstr 10 07743 Jena Germany
- Jena Center for Soft Matter (JCSM), Friedrich Schiller University Jena; Philosophenweg 7 07743 Jena Germany
| | - Joachim Kübel
- Leibnitz Institute of Photonic Technology (IPHT); Albert-Einstein-Straße 9 07745 Jena Germany
- Institute of Physical Chemistry (IPC) and Abbe Center of Photonics (ACP), Friedrich Schiller University Jena; Helmholtzweg 4 07743 Jena Germany
| | - Bernhard Häupler
- Laboratory of Organic and Macromolecular Chemistry (IOMC), Friedrich Schiller University Jena; Humboldtstr 10 07743 Jena Germany
- Jena Center for Soft Matter (JCSM), Friedrich Schiller University Jena; Philosophenweg 7 07743 Jena Germany
| | - Christian Friebe
- Laboratory of Organic and Macromolecular Chemistry (IOMC), Friedrich Schiller University Jena; Humboldtstr 10 07743 Jena Germany
- Jena Center for Soft Matter (JCSM), Friedrich Schiller University Jena; Philosophenweg 7 07743 Jena Germany
| | - Martin D. Hager
- Laboratory of Organic and Macromolecular Chemistry (IOMC), Friedrich Schiller University Jena; Humboldtstr 10 07743 Jena Germany
- Jena Center for Soft Matter (JCSM), Friedrich Schiller University Jena; Philosophenweg 7 07743 Jena Germany
| | - Andreas Winter
- Laboratory of Organic and Macromolecular Chemistry (IOMC), Friedrich Schiller University Jena; Humboldtstr 10 07743 Jena Germany
- Jena Center for Soft Matter (JCSM), Friedrich Schiller University Jena; Philosophenweg 7 07743 Jena Germany
| | - Benjamin Dietzek
- Jena Center for Soft Matter (JCSM), Friedrich Schiller University Jena; Philosophenweg 7 07743 Jena Germany
- Leibnitz Institute of Photonic Technology (IPHT); Albert-Einstein-Straße 9 07745 Jena Germany
- Institute of Physical Chemistry (IPC) and Abbe Center of Photonics (ACP), Friedrich Schiller University Jena; Helmholtzweg 4 07743 Jena Germany
| | - Ulrich S. Schubert
- Laboratory of Organic and Macromolecular Chemistry (IOMC), Friedrich Schiller University Jena; Humboldtstr 10 07743 Jena Germany
- Jena Center for Soft Matter (JCSM), Friedrich Schiller University Jena; Philosophenweg 7 07743 Jena Germany
- Dutch Polymer Institute (DPI); P.O. Box 902 5600 AX Eindhoven The Netherlands
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42
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Liu Y, Harlang T, Canton SE, Chábera P, Suárez-Alcántara K, Fleckhaus A, Vithanage DA, Göransson E, Corani A, Lomoth R, Sundström V, Wärnmark K. Towards longer-lived metal-to-ligand charge transfer states of iron(II) complexes: an N-heterocyclic carbene approach. Chem Commun (Camb) 2014; 49:6412-4. [PMID: 23752944 DOI: 10.1039/c3cc43833c] [Citation(s) in RCA: 185] [Impact Index Per Article: 18.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
A 9 ps (3)MLCT lifetime was achieved by a Fe(II) complex based on C(NHC)^N(py)^C(NHC) pincer ligands. This is the longest known so far for any kind of complexes of this abundant metal, and increased by almost two orders of magnitude compared to the reference Fe(II) bis-terpyridine complex.
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Affiliation(s)
- Yizhu Liu
- Centre for Analysis and Synthesis, Department of Chemistry, Lund University, Box 124, 22100 Lund, Sweden
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Otsuki J, Takamori Y, Sugawa K, Islam A, Ogawa K, Yamano A, Yoshikawa I, Araki K. Heteroleptic ruthenium complexes with 6-(ortho-substituted phenyl)-2,2′-bipyridine derivatives. J Organomet Chem 2014. [DOI: 10.1016/j.jorganchem.2013.10.026] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
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44
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Ghosh R, Palit DK. Probing excited state charge transfer dynamics in a heteroleptic ruthenium complex. Phys Chem Chem Phys 2014; 16:219-26. [DOI: 10.1039/c3cp53886a] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023]
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45
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Li Z, Leed NA, Dickson-Karn NM, Dunbar KR, Turro C. Directional charge transfer and highly reducing and oxidizing excited states of new dirhodium(ii,ii) complexes: potential applications in solar energy conversion. Chem Sci 2014. [DOI: 10.1039/c3sc52366g] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
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Bork MA, Vibbert HB, Stewart DJ, Fanwick PE, McMillin DR. Varying Substituents and Solvents To Maximize the Luminescence from [Ru(trpy)(bpy)CN]+ Derivatives. Inorg Chem 2013; 52:12553-60. [PMID: 24128309 DOI: 10.1021/ic4016367] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/14/2023]
Affiliation(s)
- Matthew A. Bork
- Department of Chemistry, Purdue University, 560 Oval Drive, West Lafayette, Indiana 47907-2084, United States
| | - Hunter B. Vibbert
- Department of Chemistry, Purdue University, 560 Oval Drive, West Lafayette, Indiana 47907-2084, United States
| | - David J. Stewart
- Department of Chemistry, Purdue University, 560 Oval Drive, West Lafayette, Indiana 47907-2084, United States
| | - Phillip E. Fanwick
- Department of Chemistry, Purdue University, 560 Oval Drive, West Lafayette, Indiana 47907-2084, United States
| | - David R. McMillin
- Department of Chemistry, Purdue University, 560 Oval Drive, West Lafayette, Indiana 47907-2084, United States
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47
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Sun Q, Mosquera-Vazquez S, Daku LML, Guénée L, Goodwin HA, Vauthey E, Hauser A. Experimental evidence of ultrafast quenching of the 3MLCT luminescence in ruthenium(II) tris-bipyridyl complexes via a 3dd state. J Am Chem Soc 2013; 135:13660-3. [PMID: 24000998 DOI: 10.1021/ja407225t] [Citation(s) in RCA: 115] [Impact Index Per Article: 10.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
Abstract
Ultrafast transient absorption spectroscopy serves to identify the (3)dd state as intermediate quencher state of the (3)MLCT luminescence in the non-luminescent ruthenium complexes [Ru(m-bpy)3](2+) (m-bpy = 6-methyl-2,2'-bipyridine) and [Ru(tm-bpy)3](2+) (tm-bpy = 4,4',6,6'-tetramethyl-2',2'-bipyridine). For [Ru(m-bpy)3](2+), the population of the (3)dd state from the (3)MLCT state occurs within 1.6 ps, while the return to the ground state takes 450 ps. For [Ru(tm-bpy)3](2+), the corresponding values are 0.16 and 7.5 ps, respectively. According to DFT calculations, methyl groups added in the 6 and 6' positions of bipyridine stabilize the (3)dd state by ~4000 cm(-1) each, compared to [Ru(bpy)3](2+).
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Affiliation(s)
- Qinchao Sun
- Département de chimie physique, Université de Genève , 30 Quai Ernest-Ansermet, CH-1211 Genève 4, Switzerland
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48
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Breivogel A, Meister M, Förster C, Laquai F, Heinze K. Excited state tuning of bis(tridentate) ruthenium(II) polypyridine chromophores by push-pull effects and bite angle optimization: a comprehensive experimental and theoretical study. Chemistry 2013; 19:13745-60. [PMID: 24000040 DOI: 10.1002/chem.201302231] [Citation(s) in RCA: 70] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/12/2013] [Indexed: 01/22/2023]
Abstract
The synergy of push-pull substitution and enlarged ligand bite angles has been used in functionalized heteroleptic bis(tridentate) polypyridine complexes of ruthenium(II) to shift the (1) MLCT absorption and the (3) MLCT emission to lower energy, enhance the emission quantum yield, and to prolong the (3) MLCT excited-state lifetime. In these complexes, that is, [Ru(ddpd)(EtOOC-tpy)][PF6 ]2 , [Ru(ddpd-NH2 )(EtOOC-tpy)][PF6 ]2 , [Ru(ddpd){(MeOOC)3 -tpy}][PF6 ]2 , and [Ru(ddpd-NH2 ){(EtOOC)3 -tpy}][PF6 ]2 the combination of the electron-accepting 2,2';6',2''-terpyridine (tpy) ligand equipped with one or three COOR substituents with the electron-donating N,N'-dimethyl-N,N'-dipyridin-2-ylpyridine-2,6-diamine (ddpd) ligand decorated with none or one NH2 group enforces spatially separated and orthogonal frontier orbitals with a small HOMO-LUMO gap resulting in low-energy (1) MLCT and (3) MLCT states. The extended bite angle of the ddpd ligand increases the ligand field splitting and pushes the deactivating (3) MC state to higher energy. The properties of the new isomerically pure mixed ligand complexes have been studied by using electrochemistry, UV/Vis absorption spectroscopy, static and time-resolved luminescence spectroscopy, and transient absorption spectroscopy. The experimental data were rationalized by using density functional calculations on differently charged species (charge n=0-4) and on triplet excited states ((3) MLCT and (3) MC) as well as by time-dependent density functional calculations (excited singlet states).
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Affiliation(s)
- Aaron Breivogel
- Institute of Inorganic Chemistry and Analytical Chemistry, Johannes Gutenberg-University of Mainz, Duesbergweg 10-14, 55128 Mainz (Germany), Fax: (+49) 6131-39-27-277
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49
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Tsai CN, Tian YH, Shi X, Lord RL, Schlegel HB, Chen YJ, Endicott JF. Experimental and DFT Characterization of Metal-to-Ligand Charge-Transfer Excited States of (Rutheniumammine)(Monodentate Aromatic Ligand) Chromophores. Inorg Chem 2013; 52:9774-90. [DOI: 10.1021/ic4016614] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/15/2023]
Affiliation(s)
- Chia Nung Tsai
- Department of Chemistry, Fu-Jen Catholic University, New Taipei
City 24205, Taiwan, Republic of China
- Department of Chemistry, Wayne State University, Detroit, Michigan
48202, United States
| | - Yi-Han Tian
- Department of Chemistry, Fu-Jen Catholic University, New Taipei
City 24205, Taiwan, Republic of China
| | - Xuetao Shi
- Department of Chemistry, Wayne State University, Detroit, Michigan
48202, United States
| | - Richard L. Lord
- Department of Chemistry, Wayne State University, Detroit, Michigan
48202, United States
| | - H. Bernhard Schlegel
- Department of Chemistry, Wayne State University, Detroit, Michigan
48202, United States
| | - Yuan Jang Chen
- Department of Chemistry, Fu-Jen Catholic University, New Taipei
City 24205, Taiwan, Republic of China
- Department of Chemistry, Wayne State University, Detroit, Michigan
48202, United States
| | - John F. Endicott
- Department of Chemistry, Wayne State University, Detroit, Michigan
48202, United States
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50
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Hewitt JT, Concepcion JJ, Damrauer NH. Inverse Kinetic Isotope Effect in the Excited-State Relaxation of a Ru(II)–Aquo Complex: Revealing the Impact of Hydrogen-Bond Dynamics on Nonradiative Decay. J Am Chem Soc 2013; 135:12500-3. [DOI: 10.1021/ja4037498] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Affiliation(s)
- Joshua T. Hewitt
- Department of Chemistry and
Biochemistry, University of Colorado, Boulder,
Colorado 80309, United States
| | - Javier J. Concepcion
- Department of Chemistry, The University of North Carolina, Chapel Hill, North
Carolina 27599-3290, United States
| | - Niels H. Damrauer
- Department of Chemistry and
Biochemistry, University of Colorado, Boulder,
Colorado 80309, United States
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