1
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Auty AJ, Scattergood PA, Keane T, Cheng T, Wu G, Carson H, Shipp J, Sadler A, Roseveare T, Sazanovich IV, Meijer AJHM, Chekulaev D, Elliot PIP, Towrie M, Weinstein JA. A stronger acceptor decreases the rates of charge transfer: ultrafast dynamics and on/off switching of charge separation in organometallic donor-bridge-acceptor systems. Chem Sci 2023; 14:11417-11428. [PMID: 37886100 PMCID: PMC10599469 DOI: 10.1039/d2sc06409j] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/21/2022] [Accepted: 09/23/2023] [Indexed: 10/28/2023] Open
Abstract
To unravel the role of driving force and structural changes in directing the photoinduced pathways in donor-bridge-acceptor (DBA) systems, we compared the ultrafast dynamics in novel DBAs which share a phenothiazine (PTZ) electron donor and a Pt(ii) trans-acetylide bridge (-C[triple bond, length as m-dash]C-Pt-C[triple bond, length as m-dash]C-), but bear different acceptors conjugated into the bridge (naphthalene-diimide, NDI; or naphthalene-monoimide, NAP). The excited state dynamics were elucidated by transient absorption, time-resolved infrared (TRIR, directly following electron density changes on the bridge/acceptor), and broadband fluorescence-upconversion (FLUP, directly following sub-picosecond intersystem crossing) spectroscopies, supported by TDDFT calculations. Direct conjugation of a strong acceptor into the bridge leads to switching of the lowest excited state from the intraligand 3IL state to the desired charge-separated 3CSS state. We observe two surprising effects of an increased strength of the acceptor in NDI vs. NAP: a ca. 70-fold slow-down of the 3CSS formation-(971 ps)-1vs. (14 ps)-1, and a longer lifetime of the 3CSS (5.9 vs. 1 ns); these are attributed to differences in the driving force ΔGet, and to distance dependence. The 100-fold increase in the rate of intersystem crossing-to sub-500 fs-by the stronger acceptor highlights the role of delocalisation across the heavy-atom containing bridge in this process. The close proximity of several excited states allows one to control the yield of 3CSS from ∼100% to 0% by solvent polarity. The new DBAs offer a versatile platform for investigating the role of bridge vibrations as a tool to control excited state dynamics.
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Affiliation(s)
- Alexander J Auty
- Department of Chemistry, The University of Sheffield Sheffield S3 7HF UK ,
| | | | - Theo Keane
- Department of Chemistry, The University of Sheffield Sheffield S3 7HF UK ,
| | - Tao Cheng
- Department of Chemistry, The University of Sheffield Sheffield S3 7HF UK ,
| | - Guanzhi Wu
- Department of Chemistry, The University of Sheffield Sheffield S3 7HF UK ,
| | - Heather Carson
- Department of Chemistry, The University of Sheffield Sheffield S3 7HF UK ,
| | - James Shipp
- Department of Chemistry, The University of Sheffield Sheffield S3 7HF UK ,
| | - Andrew Sadler
- Department of Chemistry, The University of Sheffield Sheffield S3 7HF UK ,
| | - Thomas Roseveare
- Department of Chemistry, The University of Sheffield Sheffield S3 7HF UK ,
| | - Igor V Sazanovich
- Laser for Science Facility, Rutherford Appleton Laboratory, RCaH, STFC OX11 0QX UK
| | | | - Dimitri Chekulaev
- Department of Chemistry, The University of Sheffield Sheffield S3 7HF UK ,
| | - Paul I P Elliot
- Department of Chemical Sciences, University of Huddersfield HD1 3DH UK
| | - Mike Towrie
- Laser for Science Facility, Rutherford Appleton Laboratory, RCaH, STFC OX11 0QX UK
| | - Julia A Weinstein
- Department of Chemistry, The University of Sheffield Sheffield S3 7HF UK ,
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2
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Niu X, Tajima K, Kong J, Tao M, Fukui N, Kuang Z, Shinokubo H, Xia A. Symmetry-breaking charge separation in a nitrogen-bridged naphthalene monoimide dimer. Phys Chem Chem Phys 2022; 24:14007-14015. [PMID: 35635531 DOI: 10.1039/d2cp00295g] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
The photophysical properties of 4-aminonaphthalene-1,8-imide-based derivatives, bis-ANI, consisting of two naphthalimide (NI) units linked by a butylamine bridge and its monomer ANI have been intensively investigated by steady-state and transient spectroscopy combined with quantum chemical calculations. The excited state relaxation dynamics of the two molecules are studied in three solvents of varying polarity - from hexane to tetrahydrofuran to acetone. A strong reduction in the fluorescence quantum yields and larger red shifts of the emission spectra are observed when going from the monomer ANI to dimer bis-ANI with increasing solvent polarity. It is found that the presence of the central amino linker in bis-ANI facilitates the formation of an asymmetric CS state between the ANI and NI moieties in bis-ANI, where NI˙- is the dominant radical anion unit after CS, evidenced by the femtosecond transient absorption measurements and spectroelectrochemistry in polar solvents. Femtosecond transient absorption spectra and quantum chemical calculations reveal the conformational change after the formation of the symmetry-breaking charge separation (SBCS) state upon photoexcitation, while a near-orthogonal structure in the excited state of bis-ANI retards charge recombination. In addition, it is evidenced that the rate of SBCS can be tuned by changing the different polar solvents.
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Affiliation(s)
- Xinmiao Niu
- State Key Laboratory of Information Photonic and Optical Communications, School of Science, Beijing University of Posts and Telecommunications (BUPT), Beijing 100176, P. R. China. .,Beijing National Laboratory for Molecular Sciences (BNLMS), Key Laboratory of Photochemistry, Institute of Chemistry, Chinese Academy of Sciences, Beijing 100190, P. R. China.,University of Chinese Academy of Sciences, Beijing 100049, P. R. China
| | - Keita Tajima
- Department of Molecular and Macromolecular Chemistry, Graduate School of Engineering, Nagoya University, Furo-cho, Chikusa-ku, Nagoya, Aichi 464-8603, Japan.
| | - Jie Kong
- Beijing National Laboratory for Molecular Sciences (BNLMS), Key Laboratory of Photochemistry, Institute of Chemistry, Chinese Academy of Sciences, Beijing 100190, P. R. China.,University of Chinese Academy of Sciences, Beijing 100049, P. R. China
| | - Min Tao
- Beijing National Laboratory for Molecular Sciences (BNLMS), Key Laboratory of Photochemistry, Institute of Chemistry, Chinese Academy of Sciences, Beijing 100190, P. R. China.,University of Chinese Academy of Sciences, Beijing 100049, P. R. China
| | - Norihito Fukui
- Department of Molecular and Macromolecular Chemistry, Graduate School of Engineering, Nagoya University, Furo-cho, Chikusa-ku, Nagoya, Aichi 464-8603, Japan.
| | - Zhuoran Kuang
- State Key Laboratory of Information Photonic and Optical Communications, School of Science, Beijing University of Posts and Telecommunications (BUPT), Beijing 100176, P. R. China.
| | - Hiroshi Shinokubo
- Department of Molecular and Macromolecular Chemistry, Graduate School of Engineering, Nagoya University, Furo-cho, Chikusa-ku, Nagoya, Aichi 464-8603, Japan.
| | - Andong Xia
- State Key Laboratory of Information Photonic and Optical Communications, School of Science, Beijing University of Posts and Telecommunications (BUPT), Beijing 100176, P. R. China. .,University of Chinese Academy of Sciences, Beijing 100049, P. R. China
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3
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Aster A, Rumble C, Bornhof AB, Huang HH, Sakai N, Šolomek T, Matile S, Vauthey E. Long-lived triplet charge-separated state in naphthalenediimide based donor-acceptor systems. Chem Sci 2021; 12:4908-4915. [PMID: 34168763 PMCID: PMC8179635 DOI: 10.1039/d1sc00285f] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
1,4,5,8-Naphthalenediimides (NDIs) are widely used motifs to design multichromophoric architectures due to their ease of functionalisation, their high oxidative power and the stability of their radical anion. The NDI building block can be incorporated in supramolecular systems by either core or imide functionalization. We report on the charge-transfer dynamics of a series of electron donor-acceptor dyads consisting of a NDI chromophore with one or two donors linked at the axial, imide position. Photo-population of the core-centred π-π* state is followed by ultrafast electron transfer from the electron donor to the NDI. Due to a solvent dependent singlet-triplet equilibrium inherent to the NDI core, both singlet and triplet charge-separated states are populated. We demonstrate that long-lived charge separation in the triplet state can be achieved by controlling the mutual orientation of the donor-acceptor sub-units. By extending this study to a supramolecular NDI-based cage, we also show that the triplet charge-separation yield can be increased by tuning the environment.
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Affiliation(s)
- Alexander Aster
- Department of Physical Chemistry, University of Geneva CH-1211 Geneva Switzerland
| | - Christopher Rumble
- Department of Physical Chemistry, University of Geneva CH-1211 Geneva Switzerland
| | - Anna-Bea Bornhof
- Department of Organic Chemistry, University of Geneva CH-1211 Geneva Switzerland
| | - Hsin-Hua Huang
- Department of Chemistry, University of Basel St. Johanns-Ring 19 Basel 4056 Switzerland
| | - Naomi Sakai
- Department of Organic Chemistry, University of Geneva CH-1211 Geneva Switzerland
| | - Tomáš Šolomek
- Department of Chemistry, University of Basel St. Johanns-Ring 19 Basel 4056 Switzerland
| | - Stefan Matile
- Department of Organic Chemistry, University of Geneva CH-1211 Geneva Switzerland
| | - Eric Vauthey
- Department of Physical Chemistry, University of Geneva CH-1211 Geneva Switzerland
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4
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Neumann S, Wenger OS, Kerzig C. Controlling Spin-Correlated Radical Pairs with Donor-Acceptor Dyads: A New Concept to Generate Reduced Metal Complexes for More Efficient Photocatalysis. Chemistry 2021; 27:4115-4123. [PMID: 33274791 PMCID: PMC7986886 DOI: 10.1002/chem.202004638] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/20/2020] [Revised: 12/02/2020] [Indexed: 12/30/2022]
Abstract
One-electron reduced metal complexes derived from photoactive ruthenium or iridium complexes are important intermediates for substrate activation steps in photoredox catalysis and for the photocatalytic generation of solar fuels. However, owing to the heavy atom effect, direct photochemical pathways to these key intermediates suffer from intrinsic efficiency problems resulting from rapid geminate recombination of radical pairs within the so-called solvent cage. In this study, we prepared and investigated molecular dyads capable of producing reduced metal complexes via an indirect pathway relying on a sequence of energy and electron transfer processes between a Ru complex and a covalently connected anthracene moiety. Our test reaction to establish the proof-of-concept is the photochemical reduction of ruthenium(tris)bipyridine by the ascorbate dianion as sacrificial donor in aqueous solution. The photochemical key step in the Ru-anthracene dyads is the reduction of a purely organic (anthracene) triplet excited state by the ascorbate dianion, yielding a spin-correlated radical pair whose (unproductive) recombination is strongly spin-forbidden. By carrying out detailed laser flash photolysis investigations, we provide clear evidence for the indirect reduced metal complex generation mechanism and show that this pathway can outperform the conventional direct metal complex photoreduction. The further optimization of our approach involving relatively simple molecular dyads might result in novel photocatalysts that convert substrates with unprecedented quantum yields.
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Affiliation(s)
- Svenja Neumann
- Department of ChemistryUniversity of BaselSt. Johanns-Ring 194056BaselSwitzerland
| | - Oliver S. Wenger
- Department of ChemistryUniversity of BaselSt. Johanns-Ring 194056BaselSwitzerland
| | - Christoph Kerzig
- Department of ChemistryUniversity of BaselSt. Johanns-Ring 194056BaselSwitzerland
- Department of ChemistryJohannes Gutenberg University MainzDuesbergweg 10—1455128MainzGermany
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5
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Luo Y, Tran JH, Wächtler M, Schulz M, Barthelmes K, Winter A, Rau S, Schubert US, Dietzek B. Remote control of electronic coupling – modification of excited-state electron-transfer rates in Ru(tpy)2-based donor–acceptor systems by remote ligand design. Chem Commun (Camb) 2019; 55:2273-2276. [DOI: 10.1039/c8cc10075f] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
Abstract
Electronic coupling (HDA) underlying the electron transfer (ET) can be tuned by the remote substituents R.
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Affiliation(s)
- Yusen Luo
- Institute of Physical Chemistry and Abbe Center of Photonics
- Friedrich Schiller University Jena
- 07743 Jena
- Germany
- Department Functional Interfaces
| | - Jens H. Tran
- Institute of Physical Chemistry and Abbe Center of Photonics
- Friedrich Schiller University Jena
- 07743 Jena
- Germany
| | - Maria Wächtler
- Institute of Physical Chemistry and Abbe Center of Photonics
- Friedrich Schiller University Jena
- 07743 Jena
- Germany
- Department Functional Interfaces
| | - Martin Schulz
- Institute of Physical Chemistry and Abbe Center of Photonics
- Friedrich Schiller University Jena
- 07743 Jena
- Germany
| | - Kevin Barthelmes
- Laboratory of Organic and Macromolecular Chemistry (IOMC)
- Friedrich Schiller University Jena
- 07743 Jena
- Germany
- Center for Energy and Environmental Chemistry Jena (CEEC Jena)
| | - Andreas Winter
- Laboratory of Organic and Macromolecular Chemistry (IOMC)
- Friedrich Schiller University Jena
- 07743 Jena
- Germany
- Center for Energy and Environmental Chemistry Jena (CEEC Jena)
| | - Sven Rau
- Institute for Inorganic Chemistry I
- Ulm University
- 89081 Ulm
- Germany
| | - Ulrich S. Schubert
- Laboratory of Organic and Macromolecular Chemistry (IOMC)
- Friedrich Schiller University Jena
- 07743 Jena
- Germany
- Center for Energy and Environmental Chemistry Jena (CEEC Jena)
| | - Benjamin Dietzek
- Institute of Physical Chemistry and Abbe Center of Photonics
- Friedrich Schiller University Jena
- 07743 Jena
- Germany
- Department Functional Interfaces
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6
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Malzkuhn S, Guo X, Häussinger D, Wenger OS. Electron Transfer across o-Phenylene Wires. J Phys Chem A 2018; 123:96-102. [PMID: 30592217 DOI: 10.1021/acs.jpca.8b11236] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Photoinduced electron transfer across rigid rod-like oligo- p-phenylenes has been thoroughly investigated in the past, but their o-connected counterparts are yet entirely unexplored in this regard. We report on three molecular dyads comprised of a triarylamine donor and a Ru(bpy)32+ (bpy =2,2'-bipyridine) acceptor connected covalently by 2 to 6 o-phenylene units. Pulsed excitation of the Ru(II) sensitizer at 532 nm leads to the rapid formation of oxidized triarylamine and reduced ruthenium complex via intramolecular electron transfer. The subsequent thermal reverse charge-shift reaction to reinstate the electronic ground-state occurs on a time scale of 120-220 ns in deaerated CH3CN at 25 °C. The conformational flexibility of the o-phenylene bridges causes multiexponential transient absorption kinetics for the photoinduced forward process, but the thermal reverse reaction produces single-exponential transient absorption decays. The key finding is that the flexible o-phenylene bridges permit rapid formation of photoproducts storing ca. 1.7 eV of energy with lifetimes on the order of hundreds of nanoseconds, similar to what is possible with rigid rod-like donor-acceptor compounds. Thus, the conformational flexibility of the o-phenylenes represents no disadvantage with regard to the photoproduct lifetimes, and this is relevant in the greater context of light-to-chemical energy conversion.
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Affiliation(s)
- Sabine Malzkuhn
- Department of Chemistry , University of Basel , St. Johanns-Ring 19 , 4056 Basel , Switzerland
| | - Xingwei Guo
- Department of Chemistry , University of Basel , St. Johanns-Ring 19 , 4056 Basel , Switzerland
| | - Daniel Häussinger
- Department of Chemistry , University of Basel , St. Johanns-Ring 19 , 4056 Basel , Switzerland
| | - Oliver S Wenger
- Department of Chemistry , University of Basel , St. Johanns-Ring 19 , 4056 Basel , Switzerland
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7
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Schäfer J, Holzapfel M, Schmiedel A, Steiner UE, Lambert C. Fine tuning of electron transfer and spin chemistry parameters in triarylamine-bridge-naphthalene diimide dyads by bridge substituents. Phys Chem Chem Phys 2018; 20:27093-27104. [PMID: 30334029 DOI: 10.1039/c8cp04910f] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
The photoinduced charge separation and charge recombination in a set of four molecular dyads consisting of a triarylamine donor and a naphthalene diimide acceptor were investigated by time resolved transient absorption spectroscopy with fs and ns time resolution. In these dyads the donor and acceptor are bridged by a meta-conjugated diethynylbenzene bridge whose electronic nature was tuned by small electron donating (OMe, Me) or electron withdrawing (Cl, CN) substituents. While the formation of the transient charge separated states is complete within tens of ps, charge recombination is biphasic with a shorter component of several hundred ns and a longer component of several microseconds. This behaviour could be rationalized by assuming an equilibrium of singlet and triplet charge separated states. Magnetic field dependent measurements showed a strong influence on the biphasic decay kinetics and also a pronounced level crossing effect in the magnetic field affected reaction yield (MARY) spectra caused by a significant exchange coupling. An analysis of the observed kinetics using classical kinetic rate equations yields rate constants for charge separation and charge recombination as well as the exchange interaction splitting in the radical ion pair, all of them showing a delicate dependence on the bridge substituents.
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Affiliation(s)
- Julian Schäfer
- Institut für Organische Chemie and Center for Nanosystems Chemistry, Universität Würzburg, Am Hubland, D-97074 Würzburg, Germany.
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8
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The sensitivity of donor - acceptor charge transfer to molecular geometry in DAN - NDI based supramolecular flower-like self-assemblies. Sci Rep 2017; 7:16501. [PMID: 29184066 PMCID: PMC5705657 DOI: 10.1038/s41598-017-15599-9] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/23/2017] [Accepted: 10/30/2017] [Indexed: 01/22/2023] Open
Abstract
A charge-transfer (CT) complex self-assembled from an electron acceptor (NDI-EA: naphthalene diimide with appended diamine) and an electron donor (DAN: phosphonic acid-appended dialkoxynapthalene) in aqueous medium. The aromatic core of the NDI and the structure of DAN1 were designed to optimize the dispersive interactions (π-π and van der Waals interactions) in the DAN1–NDI-EA self-assembly, while the amino groups of NDI also interact with the phosphonic acid of DAN1 via electrostatic forces. This arrangement prevented crystallization and favored the directional growth of 3D flower nanostructures. This molecular geometry that is necessary for charge transfer to occur was further evidenced by using a mismatching DAN2 structure. The flower-shaped assembly was visualized by scanning electron and transmission electron microscopy. The formation of the CT complex was determined by UV-vis and cyclic voltammetry and the photoinduced electron transfer to produce the radical ion pair was examined by femtosecond laser transient absorption spectroscopic measurements.
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9
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Edme K, Bettis Homan S, Nepomnyashchii AB, Weiss EA. Ultrafast exciton decay in PbS quantum dots through simultaneous electron and hole recombination with a surface-localized ion pair. Chem Phys 2016. [DOI: 10.1016/j.chemphys.2015.09.012] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
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10
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Yushchenko O, Licari G, Mosquera-Vazquez S, Sakai N, Matile S, Vauthey E. Ultrafast Intersystem-Crossing Dynamics and Breakdown of the Kasha-Vavilov's Rule of Naphthalenediimides. J Phys Chem Lett 2015; 6:2096-2100. [PMID: 26266508 DOI: 10.1021/acs.jpclett.5b00882] [Citation(s) in RCA: 49] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Abstract
The fluorescence quantum yield of a red naphthalenediimide dye (rNDI) with amino and Br core substituents has been found to decrease by a factor of almost 2 by going from S1 ← S0 to S2 ← S0 excitation. Time-resolved spectroscopic measurements reveal that this deviation from the Kasha-Vavilov's rule is due to an ultrafast, < 200 fs, intersystem-crossing (ISC) from the S2 state to the triplet manifold, due to the ππ* → nπ* character of the transition and to the presence of the heavy Br atom. In non-core substituted naphthalenediimide (pNDI), ISC is slower, ∼2 ps, and was found to be reversible on a time scale shorter than that of vibrational cooling. The fluorescence and triplet quantum yields of rNDI, thus, can be substantially changed by a simple variation of the excitation wavelength.
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Affiliation(s)
- Oleksandr Yushchenko
- School of Chemistry and Biochemistry, University of Geneva, 30 Quai Ernest Ansermet, Geneva 4 CH-1211, Switzerland
| | - Giuseppe Licari
- School of Chemistry and Biochemistry, University of Geneva, 30 Quai Ernest Ansermet, Geneva 4 CH-1211, Switzerland
| | - Sandra Mosquera-Vazquez
- School of Chemistry and Biochemistry, University of Geneva, 30 Quai Ernest Ansermet, Geneva 4 CH-1211, Switzerland
| | - Naomi Sakai
- School of Chemistry and Biochemistry, University of Geneva, 30 Quai Ernest Ansermet, Geneva 4 CH-1211, Switzerland
| | - Stefan Matile
- School of Chemistry and Biochemistry, University of Geneva, 30 Quai Ernest Ansermet, Geneva 4 CH-1211, Switzerland
| | - Eric Vauthey
- School of Chemistry and Biochemistry, University of Geneva, 30 Quai Ernest Ansermet, Geneva 4 CH-1211, Switzerland
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11
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Heinz LG, Yushchenko O, Neuburger M, Vauthey E, Wenger OS. Tetramethoxybenzene is a Good Building Block for Molecular Wires: Insights from Photoinduced Electron Transfer. J Phys Chem A 2015; 119:5676-84. [DOI: 10.1021/acs.jpca.5b03649] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Luisa G. Heinz
- Department
of Chemistry, University of Basel, St. Johanns-Ring 19, CH-4056 Basel, Switzerland
| | - Oleksandr Yushchenko
- Department
of Physical Chemistry, University of Geneva, 30 quai Ernest Ansermet, CH-1211 Geneva 4, Switzerland
| | - Markus Neuburger
- Department
of Chemistry, University of Basel, St. Johanns-Ring 19, CH-4056 Basel, Switzerland
| | - Eric Vauthey
- Department
of Physical Chemistry, University of Geneva, 30 quai Ernest Ansermet, CH-1211 Geneva 4, Switzerland
| | - Oliver S. Wenger
- Department
of Chemistry, University of Basel, St. Johanns-Ring 19, CH-4056 Basel, Switzerland
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12
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Wu YL, Brown KE, Gardner DM, Dyar SM, Wasielewski MR. Photoinduced Hole Injection into a Self-Assembled π-Extended G-Quadruplex. J Am Chem Soc 2015; 137:3981-90. [DOI: 10.1021/jacs.5b00977] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Affiliation(s)
- Yi-Lin Wu
- Department of Chemistry and
Argonne-Northwestern Solar Energy Research (ANSER) Center, Northwestern University, Evanston, Illinois 60208-3113, United States
| | - Kristen E. Brown
- Department of Chemistry and
Argonne-Northwestern Solar Energy Research (ANSER) Center, Northwestern University, Evanston, Illinois 60208-3113, United States
| | - Daniel M. Gardner
- Department of Chemistry and
Argonne-Northwestern Solar Energy Research (ANSER) Center, Northwestern University, Evanston, Illinois 60208-3113, United States
| | - Scott M. Dyar
- Department of Chemistry and
Argonne-Northwestern Solar Energy Research (ANSER) Center, Northwestern University, Evanston, Illinois 60208-3113, United States
| | - Michael R. Wasielewski
- Department of Chemistry and
Argonne-Northwestern Solar Energy Research (ANSER) Center, Northwestern University, Evanston, Illinois 60208-3113, United States
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13
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Kirk ML, Shultz DA, Stasiw DE, Lewis GF, Wang G, Brannen CL, Sommer RD, Boyle PD. Superexchange Contributions to Distance Dependence of Electron Transfer/Transport: Exchange and Electronic Coupling in Oligo(para-Phenylene)- and Oligo(2,5-Thiophene)-Bridged Donor–Bridge–Acceptor Biradical Complexes. J Am Chem Soc 2013; 135:17144-54. [DOI: 10.1021/ja4081887] [Citation(s) in RCA: 51] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Affiliation(s)
- Martin L. Kirk
- Department
of Chemistry and Chemical Biology, The University of New Mexico, MSC03
2060, 1 University of New Mexico, Albuquerque, New Mexico 87131-0001, United States
| | - David A. Shultz
- Department
of Chemistry, North Carolina State University, 2200 Hillsborough, Raleigh, North Carolina 27695-8204, United States
| | - Daniel E. Stasiw
- Department
of Chemistry, North Carolina State University, 2200 Hillsborough, Raleigh, North Carolina 27695-8204, United States
| | - Geoffrey F. Lewis
- Department
of Chemistry, North Carolina State University, 2200 Hillsborough, Raleigh, North Carolina 27695-8204, United States
| | - Guangbin Wang
- Department
of Chemistry, North Carolina State University, 2200 Hillsborough, Raleigh, North Carolina 27695-8204, United States
| | - Candice L. Brannen
- Department
of Chemistry, North Carolina State University, 2200 Hillsborough, Raleigh, North Carolina 27695-8204, United States
| | - Roger D. Sommer
- Department
of Chemistry, North Carolina State University, 2200 Hillsborough, Raleigh, North Carolina 27695-8204, United States
| | - Paul D. Boyle
- Department
of Chemistry, North Carolina State University, 2200 Hillsborough, Raleigh, North Carolina 27695-8204, United States
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14
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Avinash MB, Sandeepa KV, Govindaraju T. Molecular assembly of amino acid interlinked, topologically symmetric, π-complementary donor-acceptor-donor triads. Beilstein J Org Chem 2013; 9:1565-71. [PMID: 23946856 PMCID: PMC3740681 DOI: 10.3762/bjoc.9.178] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/23/2013] [Accepted: 07/08/2013] [Indexed: 12/15/2022] Open
Abstract
Amino acid interlinked pyrene and naphthalenediimide (NDI) based novel donor–acceptor–donor (D-A-D) triads are designed to exploit their topological symmetry and complementary π-character for facile charge-transfer complexation. Consequently, free-floating high-aspect-ratio supercoiled nanofibres and hierarchical helical bundles of triads are realized by modulating the chemical functionality of interlinking amino acids.
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Affiliation(s)
- M B Avinash
- Bioorganic Chemistry Laboratory, New Chemistry Unit, Jawaharlal Nehru Centre for Advanced Scientific Research, Jakkur, Bangalore-560064, India. ; Tel: +91 80 2208 2969
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16
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Klein JH, Sunderland TL, Kaufmann C, Holzapfel M, Schmiedel A, Lambert C. Stepwise versus pseudo-concerted two-electron-transfer in a triarylamine–iridium dipyrrin–naphthalene diimide triad. Phys Chem Chem Phys 2013; 15:16024-30. [DOI: 10.1039/c3cp51981c] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
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17
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Kirk ML, Shultz DA, Depperman EC, Habel-Rodriguez D, Schmidt RD. Spectroscopic studies of bridge contributions to electronic coupling in a donor-bridge-acceptor biradical system. J Am Chem Soc 2012; 134:7812-9. [PMID: 22480156 PMCID: PMC3398980 DOI: 10.1021/ja300233a] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
Variable-temperature electronic absorption and resonance Raman spectroscopies are used to probe the excited state electronic structure of Tp(Cum,Me)Zn(SQ-Ph-NN) (1), a donor-bridge-acceptor (D-B-A) biradical complex and a ground state analogue of the charge-separated excited state formed in photoinduced electron transfer reactions. Strong electronic coupling mediated by the p-phenylene bridge stabilizes the triplet ground state of this molecule. Detailed spectroscopic and bonding calculations elucidate key bridge distortions that are involved in the SQ(π)(SOMO) → NN-Ph (π*)(LUMO) D → A charge transfer (CT) transition. We show that the primary excited state distortion that accompanies this CT is along a vibrational coordinate best described as a symmetric Ph(8a) + SQ(in-plane) linear combination and underscores the dominant role of the phenylene bridge fragment acting as an electron acceptor in the D-B-A charge transfer state. Our results show the importance of the phenylene bridge in promoting (1) electron transfer in D-Ph-A systems and (2) electron transport in biased electrode devices that employ a 1,4-phenylene linkage. We have also developed a relationship between the spin density on the acceptor, as measured via the isotropic NN nitrogen hyperfine interaction, and the strength of the D → A interaction given by the magnitude of the electronic coupling matrix element, H(ab).
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Affiliation(s)
- Martin L. Kirk
- Department of Chemistry and Chemical Biology, The University of New Mexico, MSC03 2060, 1 University of New Mexico, Albuquerque, NM 87131-0001
| | - David A. Shultz
- Department of Chemistry, North Carolina State University, Raleigh, NC 27695-8204
| | - Ezra C. Depperman
- Department of Chemistry and Chemical Biology, The University of New Mexico, MSC03 2060, 1 University of New Mexico, Albuquerque, NM 87131-0001
| | - Diana Habel-Rodriguez
- Department of Chemistry and Chemical Biology, The University of New Mexico, MSC03 2060, 1 University of New Mexico, Albuquerque, NM 87131-0001
| | - Robert D. Schmidt
- Department of Chemistry, North Carolina State University, Raleigh, NC 27695-8204
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18
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Bhosale SV, Hackbarth S, Langford SJ, Bhosale SV. Light-induced electron transfer over distances of 5, 10, and 15 Å within water-filled yoctowells. Chem Asian J 2012; 7:176-82. [PMID: 22038956 DOI: 10.1002/asia.201100533] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2011] [Indexed: 11/10/2022]
Abstract
A small series of variable-depth yoctowell cavities with 'functional' walls on aminated silica particles and gold electrodes has been established. The dimensions of the gaps formed were 2.2 nm in diameter with varying 'functional' depths of 5, 10, and 15 Å, depending on the length of bolaphiles applied and the position of the positive rim; these gaps were prepared through a Michael addition of the incorporated ene-amide groups. Using this construct and electrostatic interactions between the positive rim and anionic quinones as a means of immobilization, a porphyrin-quinone dyad system has been prepared. The distance between the donor and acceptor was changed systematically in aqueous solution, whilst maintaining a similar environment in each case. Upon photoexcitation of the porphyrin, efficient electron transfer occurs between the porphyrin and quinone units in a distance-dependent manner on the nanosecond timescale.
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Hankache J, Wenger OS. Photoinduced electron transfer in covalent ruthenium–anthraquinone dyads: relative importance of driving-force, solvent polarity, and donor–bridge energy gap. Phys Chem Chem Phys 2012; 14:2685-92. [DOI: 10.1039/c2cp23240e] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/14/2022]
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20
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Walther ME, Wenger OS. Hole Tunneling and Hopping in a Ru(bpy)32+-Phenothiazine Dyad with a Bridge Derived from oligo-p-Phenylene. Inorg Chem 2011; 50:10901-7. [DOI: 10.1021/ic201446x] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Affiliation(s)
- Mathieu E. Walther
- Institut für Anorganische Chemie, Georg-August-Universität Göttingen, Tammannstrasse 4, D-37077 Göttingen, Germany
| | - Oliver S. Wenger
- Institut für Anorganische Chemie, Georg-August-Universität Göttingen, Tammannstrasse 4, D-37077 Göttingen, Germany
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Affiliation(s)
- Jihane Hankache
- Institut für Anorganische Chemie, Georg-August-Universität Göttingen, Tammannstrasse 4, D-37077 Göttingen, Germany
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Abstract
Phenylene oligomers represent a borderline case between very strongly π-conjugated molecular wires such as oligo-p-phenylene vinylenes and saturated molecular bridges. Even subtle chemical modifications of phenylene oligomers can therefore have a strong impact on charge transfer rates and mechanisms. On the basis of recently published selected case studies, this tutorial review discusses the key factors that affect charge transfer kinetics in phenylene oligomers with particular focus on the role of donor-bridge energy matching. Selected examples of triplet-triplet energy transfer reactions across phenylene oligomers are also discussed.
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Affiliation(s)
- Oliver S Wenger
- Georg-August-Universität Göttingen, Institut für Anorganische Chemie, Tammannstrasse 4, 37077 Göttingen, Germany.
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24
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Indelli MT, Chiorboli C, Scandola F, Iengo E, Osswald P, Würthner F. Photoinduced Processes in Self-Assembled Porphyrin/Perylene Bisimide Metallosupramolecular Boxes. J Phys Chem B 2010; 114:14495-504. [DOI: 10.1021/jp101849m] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/30/2023]
Affiliation(s)
- M. Teresa Indelli
- Dipartimento di Chimica, Università di Ferrara, 44100 Ferrara, Italy, ISOF-CNR, Sezione di Ferrara, 44100 Ferrara, Italy, Centro di Ricerca Interuniversitario per la Conversione Chimica dell’Energia Solare, Sezione di Ferrara, 44100 Ferrara, Italy, Dipartimento di Scienze Chimiche, Università di Trieste, 34127, Trieste, Italy, and Institut für Organische Chemie and Röntgen Research Center for Complex Material Systems, Universität Würzburg, 97074 Würzburg, Germany
| | - Claudio Chiorboli
- Dipartimento di Chimica, Università di Ferrara, 44100 Ferrara, Italy, ISOF-CNR, Sezione di Ferrara, 44100 Ferrara, Italy, Centro di Ricerca Interuniversitario per la Conversione Chimica dell’Energia Solare, Sezione di Ferrara, 44100 Ferrara, Italy, Dipartimento di Scienze Chimiche, Università di Trieste, 34127, Trieste, Italy, and Institut für Organische Chemie and Röntgen Research Center for Complex Material Systems, Universität Würzburg, 97074 Würzburg, Germany
| | - Franco Scandola
- Dipartimento di Chimica, Università di Ferrara, 44100 Ferrara, Italy, ISOF-CNR, Sezione di Ferrara, 44100 Ferrara, Italy, Centro di Ricerca Interuniversitario per la Conversione Chimica dell’Energia Solare, Sezione di Ferrara, 44100 Ferrara, Italy, Dipartimento di Scienze Chimiche, Università di Trieste, 34127, Trieste, Italy, and Institut für Organische Chemie and Röntgen Research Center for Complex Material Systems, Universität Würzburg, 97074 Würzburg, Germany
| | - Elisabetta Iengo
- Dipartimento di Chimica, Università di Ferrara, 44100 Ferrara, Italy, ISOF-CNR, Sezione di Ferrara, 44100 Ferrara, Italy, Centro di Ricerca Interuniversitario per la Conversione Chimica dell’Energia Solare, Sezione di Ferrara, 44100 Ferrara, Italy, Dipartimento di Scienze Chimiche, Università di Trieste, 34127, Trieste, Italy, and Institut für Organische Chemie and Röntgen Research Center for Complex Material Systems, Universität Würzburg, 97074 Würzburg, Germany
| | - Peter Osswald
- Dipartimento di Chimica, Università di Ferrara, 44100 Ferrara, Italy, ISOF-CNR, Sezione di Ferrara, 44100 Ferrara, Italy, Centro di Ricerca Interuniversitario per la Conversione Chimica dell’Energia Solare, Sezione di Ferrara, 44100 Ferrara, Italy, Dipartimento di Scienze Chimiche, Università di Trieste, 34127, Trieste, Italy, and Institut für Organische Chemie and Röntgen Research Center for Complex Material Systems, Universität Würzburg, 97074 Würzburg, Germany
| | - Frank Würthner
- Dipartimento di Chimica, Università di Ferrara, 44100 Ferrara, Italy, ISOF-CNR, Sezione di Ferrara, 44100 Ferrara, Italy, Centro di Ricerca Interuniversitario per la Conversione Chimica dell’Energia Solare, Sezione di Ferrara, 44100 Ferrara, Italy, Dipartimento di Scienze Chimiche, Università di Trieste, 34127, Trieste, Italy, and Institut für Organische Chemie and Röntgen Research Center for Complex Material Systems, Universität Würzburg, 97074 Würzburg, Germany
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25
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Flamigni L, Wyrostek D, Voloshchuk R, Gryko DT. Solvent polarity effect on intramolecular electron transfer in a corrole–naphthalene bisimide dyad. Phys Chem Chem Phys 2010; 12:474-83. [DOI: 10.1039/b916525h] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023]
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26
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Fürstenberg A, Kel O, Gradinaru J, Ward TR, Emery D, Bollot G, Mareda J, Vauthey E. Site-dependent excited-state dynamics of a fluorescent probe bound to avidin and streptavidin. Chemphyschem 2009; 10:1517-32. [PMID: 19565577 DOI: 10.1002/cphc.200900132] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
The excited-state dynamics of biotin-spacer-Lucifer-Yellow (LY) constructs bound to avidin (Avi) and streptavidin (Sav) was investigated using femtosecond spectroscopy. Two different locations in the proteins, identified by molecular dynamics simulations of Sav, namely the entrance of the binding pocket and the protein surface, were probed by varying the length of the spacer. A reduction of the excited-state lifetime, stronger in Sav than in Avi, was observed with the long spacer construct. Transient absorption measurements show that this effect originates from an electron transfer quenching of LY, most probably by a nearby tryptophan residue. The local environment of the LY chromophore could be probed by measuring the time-dependent polarisation anisotropy and Stokes shift of the fluorescence. Substantial differences in both dynamics were observed. The fluorescence anisotropy decays analysed by using the wobbling-in-a-cone model reveal a much more constrained environment of the chromophore with the short spacer. Moreover, the dynamic Stokes shift is multiphasic in all cases, with a approximately 1 ps component that can be ascribed to diffusive motion of bulk-like water molecules, and with slower components with time constants varying not only with the spacer, but with the protein as well. These slow components, which depend strongly on the local environment of the probe, are ascribed to the motion of the hydration layer coupled to the conformational dynamics of the protein.
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Affiliation(s)
- Alexandre Fürstenberg
- Department of Physical Chemistry, University of Geneva, 30, quai Ernest-Ansermet, CH-1211 Geneva, 4, Switzerland
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27
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Evans DH. One-Electron and Two-Electron Transfers in Electrochemistry and Homogeneous Solution Reactions. Chem Rev 2008; 108:2113-44. [DOI: 10.1021/cr068066l] [Citation(s) in RCA: 273] [Impact Index Per Article: 17.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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28
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Bonesi SM, Manet I, Freccero M, Fagnoni M, Albini A. Photosensitized oxidation of sulfides: discriminating between the singlet-oxygen mechanism and electron transfer involving superoxide anion or molecular oxygen. Chemistry 2007; 12:4844-57. [PMID: 16598801 DOI: 10.1002/chem.200501144] [Citation(s) in RCA: 104] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
The oxidation of diethyl and diphenyl sulfide photosensitized by dicyanoanthracene (DCA), N-methylquinolinium tetrafluoroborate (NMQ(+)), and triphenylpyrylium tetrafluoroborate (TPP(+)) has been explored by steady-state and laser flash photolysis studies in acetonitrile, methanol, and 1,2-dichloroethane. In the Et(2)S/DCA system sulfide-enhanced intersystem crossing leads to generation of (1)O(2), which eventually gives the sulfoxide via a persulfoxide; this mechanism plays no role with Ph(2)S, though enhanced formation of (3)DCA has been demonstrated. In all other cases an electron-transfer (ET) mechanism is involved. Electron-transfer sulfoxidation occurs with efficiency essentially independent of the sulfide structure, is subject to quenching by benzoquinone, and does not lead to Ph(2)SO cooxidation. Formation of the radical cations R(2)S(*+) has been assessed by flash photolysis (medium-dependent yield, dichloroethane>>CH(3)CN>CH(3)OH) and confirmed by quenching with 1,4-dimethoxybenzene. Electron-transfer oxidations occur both when the superoxide anion is generated by the reduced sensitizer (DCA(*-), NMQ(*)) and when this is not the case (TPP(*)). Although it is possible that different mechanisms operate with different ET sensitizers, a plausible unitary mechanism can be proposed. This considers that reaction between R(2)S(*+) and O(2)(*-) mainly involves back electron transfer, whereas sulfoxidation results primarily from the reaction of the sulfide radical cation with molecular oxygen. Calculations indeed show that the initially formed fleeting complex RS(2)(+)...O-O(*) adds to a sulfide molecule and gives strongly stabilized R(2)S-O(*)-(+)O-SR(2) via an accessible transition state. This intermediate gives the sulfoxide, probably via a radical cation chain path. This mechanism explains the larger scope of ET sulfoxidation with respect to the singlet-oxygen process.
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Affiliation(s)
- Sergio M Bonesi
- CHIDECAR-CONICET, Dep. Quim. Org., Fac. Cien. Ex. Nat. Universidad de Buenos Aires, Ciudad Universidaria, 1428 Buenos Aires, Argentina
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29
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Flamigni L, Baranoff E, Collin JP, Sauvage JP. A Triad Based on an Iridium(III) Bisterpyridine Complex Leading to a Charge-Separated State with a 120-μs Lifetime at Room Temperature. Chemistry 2006; 12:6592-606. [PMID: 16807945 DOI: 10.1002/chem.200600002] [Citation(s) in RCA: 69] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Abstract
A triad D-Ir-A, where Ir is an Ir(III) bisterpyridine complex connected through an amidophenyl spacer to D, a triphenylamine electron donor, and to A, a naphthalene bisimide electron acceptor, has been synthesized and electrochemically investigated. The photoinduced processes in the triad, which is more than 4-nm long, have been characterized by steady-state and time-resolved optical spectroscopy by comparison with the model dyads D-Ir, Ir-A, and the reference monomers D, Ir, and A. A sequential electron transfer occurs upon excitation of the D and Ir units, leading to the charge-separated state D+-Ir- -A in 100 % yield and subsequently to D+-Ir-A- in about 10 % yield. The final charge-separated state has a lifetime at room temperature of 120 micros in air-free acetonitrile and of 100 micros in air-equilibrated solvent. Excitation of the A units does not yield intramolecular reactivity, but the resulting triplet-excited state localized on the acceptor, D-Ir-3A, displays intermolecular reactivity.
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Affiliation(s)
- Lucia Flamigni
- Instituto ISOF-CNR, Via P. Gobetti 101, 40129 Bologna, Italy
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30
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Hoertz PG, Mallouk TE. Light-to-Chemical Energy Conversion in Lamellar Solids and Thin Films. Inorg Chem 2005; 44:6828-40. [PMID: 16180839 DOI: 10.1021/ic050779j] [Citation(s) in RCA: 124] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/17/2023]
Abstract
Photocatalytic water splitting by visible light is one of the most difficult and persistent challenges in chemistry. This Forum Article reviews progress in this field, focusing on efforts made in our laboratory to control electron- and energy-transfer reactions, and catalytic hydrogen and oxygen evolution, in lamellar solids and thin films.
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Affiliation(s)
- Paul G Hoertz
- Department of Chemistry, Pennsylvania State University, University Park, 16802, USA
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31
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Nakamura T, Ikemoto JY, Fujitsuka M, Araki Y, Ito O, Takimiya K, Aso Y, Otsubo T. Control of Photoinduced Energy- and Electron-Transfer Steps in Zinc Porphyrin−Oligothiophene−Fullerene Linked Triads with Solvent Polarity. J Phys Chem B 2005; 109:14365-74. [PMID: 16852807 DOI: 10.1021/jp044316v] [Citation(s) in RCA: 39] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
The dramatic changes of the lifetimes of the charge-separated (CS) states were confirmed in zinc porphyrin (ZnP)-oligothiophene (nT)-fullerene (C(60)) linked triads (ZnP-nT-C(60)) with the solvent polarity. After the selective excitation of the ZnP moiety of ZnP-nT-C(60), an energy transfer took place from the (1)ZnP moiety to the C(60) moiety, generating ZnP-nT-(1)C(60). In polar solvents, the CS process also took place directly via the (1)ZnP moiety, generating ZnP(*+)-nT-C(60)(*-), as well as the energy transfer to the C(60) moiety. After this energy transfer, an indirect CS process took place from the (1)C(60) moiety. In the less polar solvent anisole, the radical cation (hole) of ZnP(*+)-nT-C(60)(*-) shifted to the nT moiety; thus, the nT moiety behaves as a cation trapper, and the rates of the hole shift were evaluated to be in the order of 10(8) s(-1); then, the final CS states ZnP-nT(*+)-C(60)(*-) were lasting for 6-7 mus. In the medium polar solvent o-dichlorobenzene (o-DCB), ZnP-nT(*+)-C(60)(*-) and ZnP(*+)-nT-C(60)(*-) were present as an equilibrium, because both states have almost the same thermodynamic stability. This equilibrium resulted in quite long lifetimes of the CS states (450-910 mus) in o-DCB. In the more polar benzonitrile, the generation of ZnP-nT(*+)-C(60)(*-) was confirmed with apparent short lifetimes (0.6-0.8 mus), which can be explained by the fast hole shift to more stable ZnP(*+)-nT-C(60)(*-) followed by the faster charge recombination. It was revealed that the relation between the energy levels of two CS states, which strongly depend on the solvent polarity, causes dramatic changes of the lifetimes of the CS states in ZnP-nT-C(60); that is, the most appropriate solvents for the long-lived CS state are intermediately polar solvents such as o-DCB. Compared with our previous data for H(2)P-nT-C(60), in which H(2)P is free-base porphyrin, the lifetimes of the CS states of ZnP-nT-C(60) are approximately 30 times longer than those in o-DCB.
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Affiliation(s)
- Takumi Nakamura
- Institute of Multidisciplinary Research for Advanced Materials, Tohoku University, CREST (JST), Katahira, Sendai, Miyagi 980-8577, Japan
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32
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Lainé PP, Ciofini I, Ochsenbein P, Amouyal E, Adamo C, Bedioui F. Photoinduced Processes within Compact Dyads Based on Triphenylpyridinium-Functionalized Bipyridyl Complexes of Ruthenium(II). Chemistry 2005; 11:3711-27. [PMID: 15822134 DOI: 10.1002/chem.200401150] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
As an alternative to conventional charge-separation functional molecular models based on long-range ET within redox cascades, a "compact approach" has been examined. To this end, spacer elements usually inserted between main redox-active units within polyad systems have been removed, allowing extended rigidity but at the expense of enhanced intercomponent electronic communication. The molecular assemblies investigated here are of the P-(theta (1))-A type, where the theta (1) twist angle is related to the degree of conjugation between the photosensitizer (P, of {Ru(bpy)(3)}(2+) type) and the electron-acceptor (A). 4-N- and 4-N-,4'-N-(2,4,6-triphenylpyridinio)-2,2'-bipyridine ligands (A(1)-bpy and A(2)-bpy, respectively) have been synthesized to give complexes with Ru(II), 1-bpy and 2-bpy, respectively. Combined solid-state analysis (X-ray crystallography), solution studies ((1)H NMR, cyclic voltammetry) and computational structural optimization allowed verifying that theta (1) angle approaches 90 degrees within 1-bpy and 2-bpy in solution. Also, anticipated existence of strong intercomponent electronic coupling has been confirmed by investigating electronic absorption properties and electrochemical behavior of the compounds. The capability of 1-bpy and 2-bpy to undergo PET process was evaluated by carrying out their photophysical study (steady state emission and time-resolved spectroscopy at both 293 and 77 K). The conformational dependence of photoinduced processes within P-(theta (1))-A systems has been established by comparing the photophysical properties of 1-bpy (and 2-bpy) with those of an affiliated species reported in the literature, 1-phen. A complementary theoretical analysis (DFT) of the change of spin density distribution within model [1-bpy(theta (1))](-) mono-reduced species as a function of theta (1) has been undertaken and the possibility of conformationally switching emission properties of P was derived.
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Affiliation(s)
- Philippe P Lainé
- Laboratoire de Chimie et Biochimie Pharmacologiques et Toxicologiques (CNRS UMR 8601), Université René Descartes, Paris, France.
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33
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Vail SA, Krawczuk PJ, Guldi DM, Palkar A, Echegoyen L, Tomé JPC, Fazio MA, Schuster DI. Energy and Electron Transfer in Polyacetylene-Linked Zinc-Porphyrin-[60]Fullerene Molecular Wires. Chemistry 2005; 11:3375-88. [PMID: 15803520 DOI: 10.1002/chem.200401348] [Citation(s) in RCA: 100] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
The synthesis and electrochemical and photophysical studies of a series of alkyne-linked zinc-porphyrin-[60]fullerene dyads are described. These dyads represent a new class of fully conjugated donor-acceptor systems. An alkynyl-fullerene synthon was synthesized by a nucleophilic addition reaction, and was then oxidatively coupled with a series of alkynyl tetra-aryl zinc-porphyrins with 1-3 alkyne units. Cyclic and differential pulse voltammetry studies confirmed that the porphyrin and fullerene are electronically coupled and that the degree of electronic interaction decreases with increasing length of the alkyne bridge. In toluene, energy transfer from the excited zinc-porphyrin singlet to the fullerene moiety occurs, affording fullerene triplet quantum yields of greater than 90 %. These dyads exhibit very rapid photoinduced electron transfer in tetrahydrofuran (THF) and benzonitrile (PhCN), which is consistent with normal Marcus behavior. Slower rates for charge recombination in THF versus PhCN clearly indicate that charge-recombination events are occurring in the Marcus inverted region. Exceptionally small attenuation factors (beta) of 0.06+/-0.005 A(-1) demonstrate that the triple bond is an effective mediator of electronic interaction in zinc-porphyrin-alkyne-fullerene molecular wires.
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Affiliation(s)
- Sean A Vail
- Department of Chemistry, New York University, 100 Washington Square East, New York, NY 10003, USA
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34
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Sviridenko FB, Stass DV, Kobzeva TV, Tretyakov EV, Klyatskaya SV, Mshvidobadze EV, Vasilevsky SF, Molin YN. Optically Detected ESR and Low Magnetic Field Signals from Spin Triads: 2-Imidazoline-1-Oxyl Derivatives in X-irradiated Alkane Liquids as a Method to Study Three-Spin Systems. J Am Chem Soc 2004; 126:2807-19. [PMID: 14995198 DOI: 10.1021/ja037157m] [Citation(s) in RCA: 43] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
This contribution reports the design and synthesis of a series of spin-labeled charge acceptors to produce three-spin systems of "radical ion/biradical ion" type in X-irradiated alkane liquids. This opens the way to study spin triads in experimental conditions, in which short-lived radical ion pairs are conventionally studied, thus offering optically detected techniques such as magneto-resonance OD ESR and level-crossing MARY spectroscopy. The structure of the synthesized 2-imidazoline-1-oxyl derivatives is A-Sp-R, where A is a positive or negative charge acceptor, R is a stable radical, and Sp is a hydrocarbon bridge. The set of 20+ compounds represent a convenient tool to construct experimental three-spin systems with various properties, e.g. with the "third" spin introduced into one or the other partner of the radical ion pair. The degree of exchange coupling between the two paramagnetic fragments in the biradical ion has been demonstrated to strongly depend on the type of the radical fragment R and the structure of the bridge Sp. As a result, a series of acceptors with systematically reduced exchange interaction has been synthesized, and optimal systems for the observation of low magnetic field effect have been found. In the most favorable case, an OD ESR signal from a spin triad living as short as ca. 100 ns has been registered as a single unresolved line. The exchange integral for this biradical anion (9) was estimated from OD ESR and ESR experiments to be ca. 10(3) G by the order of magnitude, which is much greater than the hyperfine couplings in the biradical ion but much smaller than the thermal energy kT.
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Affiliation(s)
- Fyodor B Sviridenko
- Institute of Chemical Kinetics and Combustion SB RAS, Institutskaya 3, Novosibirsk 630090, Russia.
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35
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Li G, Bhosale SV, Wang T, Hackbarth S, Roeder B, Siggel U, Fuhrhop JH. Nanowells on silica particles in water containing long-distance porphyrin heterodimers. J Am Chem Soc 2003; 125:10693-702. [PMID: 12940755 DOI: 10.1021/ja035558w] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Smooth and nonswelling spherical silica particles with a diameter of 100 nm and an aminopropyl coating are soluble in water at pH 11, coagulate quickly at pH 3, and redissolve at pH 9. Electron microscopy as well as visible spectra of covalently attached porphyrins indicate the aggregation state of the particles. Long-chain alpha,omega-dicarboxylic acids with a terminal oligoethyleneglycol (=OEG)-amide group were attached in a second self-assembly step to the remaining amine groups around the porphyrins. Form-stable 2-nm wells were thus obtained and were characterized by fluorescence quenching experiments using the bottom porphyrin as a target. The one-dimensional diffusion of fitting quencher molecules along the 2-nm pathway took several minutes. Porphyrins with a diameter above 2 nm could not enter the form-stable gaps at all. Added tyrosine stuck irreversibly to the walls of the nanowells and prevented the entrance of quencher molecules, the OEG-headgroups fixated 2,6-diaminoanthraquinone. A ring of methylammonium groups was then fixed at the walls of the wells at a distance of 5 or 10 A with respect to the bottom porphyrin. 2,6-Disulfonatoanthraquinone was attached only loosely to this ring, but the exactly fitting manganese(III) meso-(tetraphenyl-4-sulfonato)porphyrinate (Mn(III) TPPS) was tightly bound. Transient fluorescence experiments showed a fast decay time of 0.2 ns for the bottom porphyrin, when the Mn(III) TPPS was fixated at a distance of 5 A. Two different dyes have thus been immobilized at a defined subnanometer distance in an aqueous medium.
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Affiliation(s)
- Guangtao Li
- Freie Universität Berlin FB Biologie, Chemie, Pharmazie Institut für Chemie/Organische Chemie, Takustrasse 3, D-14195 Berlin, Germany
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Fu PKL, Bradley PM, van Loyen D, Dürr H, Bossmann SH, Turro C. DNA photocleavage by a supramolecular Ru(II)-viologen complex. Inorg Chem 2002; 41:3808-10. [PMID: 12132903 DOI: 10.1021/ic020136t] [Citation(s) in RCA: 45] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/13/2023]
Abstract
A novel Ru(II) complex possessing two sequentially linked viologen units, Ru-V(1)-V(2)(6+), was synthesized and characterized. Upon excitation of the Ru(II) unit (lambda(exc) = 532 nm, fwhm approximately 10 ns), a long-lived charge-separated (CS) state is observed (tau = 1.7 micros) by transient absorption spectroscopy. Unlike Ru(bpy)(3)(2+), which cleaves DNA upon photolysis through the formation of reactive oxygen species, such as (1)O(2) and O(2)(-), the photocleavage of plasmid DNA by Ru-V(1)-V(2)(6+) is observed both in air and under N(2) atmosphere (lambda(irr) > 395 nm).
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Affiliation(s)
- Patty K-L Fu
- Department of Chemistry, The Ohio State University, Columbus, OH 43210, USA
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Jana AK, Mukhopadhyay SK, Bhowmik BB. Absorption spectra of nitroanilines in micellar solution--II. SPECTROCHIMICA ACTA. PART A, MOLECULAR AND BIOMOLECULAR SPECTROSCOPY 2002; 58:1697-1702. [PMID: 12166740 DOI: 10.1016/s1386-1425(01)00621-7] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
Abstract
The absorption spectra of nitroanilines (o-, m- and p-) in aqueous and nonaqueous solution of neutral surfactant-Triton X-100 (TX-100) reveal many interesting phenomena. Nitroanilines and TX-100 behave as electron acceptor and donor, respectively, in both media during charge-transfer (CT) complex formation though water plays an important role in aqueous media. The thermodynamic and spectrophotometric parameters of nitroanilines-TX-100 interactions in two media have been determined and the electron accepting capability among the nitroanilines have been also established. In addition to this, role of surface in CT interaction, the site of CT interaction, intensity and stability of CT interaction between nitroanilines and TX-100 have been pointed out.
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Affiliation(s)
- Asok K Jana
- Department of Chemistry, Kanchi Mamunivar Centre for Post-Graduate Studies, Lawspet, Pondicherry, India
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Mori Y, Sakaguchi Y, Hayashi H. Spin Effects on Decay Dynamics of Charge-Separated States Generated by Photoinduced Electron Transfer in Zinc Porphyrin−Naphthalenediimide Dyads. J Phys Chem A 2002. [DOI: 10.1021/jp013453e] [Citation(s) in RCA: 38] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
Affiliation(s)
- Yukie Mori
- Molecular Photochemistry Laboratory, RIKEN, The Institute of Physical and Chemical Research, Hirosawa, Wako, Saitama, 351-0198, Japan
| | - Yoshio Sakaguchi
- Molecular Photochemistry Laboratory, RIKEN, The Institute of Physical and Chemical Research, Hirosawa, Wako, Saitama, 351-0198, Japan
| | - Hisaharu Hayashi
- Molecular Photochemistry Laboratory, RIKEN, The Institute of Physical and Chemical Research, Hirosawa, Wako, Saitama, 351-0198, Japan
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Imahori H, Tamaki K, Araki Y, Hasobe T, Ito O, Shimomura A, Kundu S, Okada T, Sakata Y, Fukuzumi S. Linkage Dependent Charge Separation and Charge Recombination in Porphyrin-Pyromellitimide-Fullerene Triads. J Phys Chem A 2002. [DOI: 10.1021/jp014433f] [Citation(s) in RCA: 39] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/20/2023]
Affiliation(s)
- Hiroshi Imahori
- Department of Material and Life Science, Graduate School of Engineering, Osaka University, CREST, Japan Science and Technology Corporation (JST), Suita, Osaka 565-0871, Japan, and The Institute of Scientific and Industrial Research, Osaka University, 8-1 Mihoga-oka, Ibaraki, Osaka 567-0047, Japan, and Institute for Multidisciplinary Research for Advanced Materials, Tohoku University, CREST, Japan Science and Technology Corporation (JST), Katahira, Aoba-ku, Sendai 980-8577, Japan, and Department of
| | - Koichi Tamaki
- Department of Material and Life Science, Graduate School of Engineering, Osaka University, CREST, Japan Science and Technology Corporation (JST), Suita, Osaka 565-0871, Japan, and The Institute of Scientific and Industrial Research, Osaka University, 8-1 Mihoga-oka, Ibaraki, Osaka 567-0047, Japan, and Institute for Multidisciplinary Research for Advanced Materials, Tohoku University, CREST, Japan Science and Technology Corporation (JST), Katahira, Aoba-ku, Sendai 980-8577, Japan, and Department of
| | - Yasuyuki Araki
- Department of Material and Life Science, Graduate School of Engineering, Osaka University, CREST, Japan Science and Technology Corporation (JST), Suita, Osaka 565-0871, Japan, and The Institute of Scientific and Industrial Research, Osaka University, 8-1 Mihoga-oka, Ibaraki, Osaka 567-0047, Japan, and Institute for Multidisciplinary Research for Advanced Materials, Tohoku University, CREST, Japan Science and Technology Corporation (JST), Katahira, Aoba-ku, Sendai 980-8577, Japan, and Department of
| | - Taku Hasobe
- Department of Material and Life Science, Graduate School of Engineering, Osaka University, CREST, Japan Science and Technology Corporation (JST), Suita, Osaka 565-0871, Japan, and The Institute of Scientific and Industrial Research, Osaka University, 8-1 Mihoga-oka, Ibaraki, Osaka 567-0047, Japan, and Institute for Multidisciplinary Research for Advanced Materials, Tohoku University, CREST, Japan Science and Technology Corporation (JST), Katahira, Aoba-ku, Sendai 980-8577, Japan, and Department of
| | - Osamu Ito
- Department of Material and Life Science, Graduate School of Engineering, Osaka University, CREST, Japan Science and Technology Corporation (JST), Suita, Osaka 565-0871, Japan, and The Institute of Scientific and Industrial Research, Osaka University, 8-1 Mihoga-oka, Ibaraki, Osaka 567-0047, Japan, and Institute for Multidisciplinary Research for Advanced Materials, Tohoku University, CREST, Japan Science and Technology Corporation (JST), Katahira, Aoba-ku, Sendai 980-8577, Japan, and Department of
| | - Akihisa Shimomura
- Department of Material and Life Science, Graduate School of Engineering, Osaka University, CREST, Japan Science and Technology Corporation (JST), Suita, Osaka 565-0871, Japan, and The Institute of Scientific and Industrial Research, Osaka University, 8-1 Mihoga-oka, Ibaraki, Osaka 567-0047, Japan, and Institute for Multidisciplinary Research for Advanced Materials, Tohoku University, CREST, Japan Science and Technology Corporation (JST), Katahira, Aoba-ku, Sendai 980-8577, Japan, and Department of
| | - Santi Kundu
- Department of Material and Life Science, Graduate School of Engineering, Osaka University, CREST, Japan Science and Technology Corporation (JST), Suita, Osaka 565-0871, Japan, and The Institute of Scientific and Industrial Research, Osaka University, 8-1 Mihoga-oka, Ibaraki, Osaka 567-0047, Japan, and Institute for Multidisciplinary Research for Advanced Materials, Tohoku University, CREST, Japan Science and Technology Corporation (JST), Katahira, Aoba-ku, Sendai 980-8577, Japan, and Department of
| | - Tadashi Okada
- Department of Material and Life Science, Graduate School of Engineering, Osaka University, CREST, Japan Science and Technology Corporation (JST), Suita, Osaka 565-0871, Japan, and The Institute of Scientific and Industrial Research, Osaka University, 8-1 Mihoga-oka, Ibaraki, Osaka 567-0047, Japan, and Institute for Multidisciplinary Research for Advanced Materials, Tohoku University, CREST, Japan Science and Technology Corporation (JST), Katahira, Aoba-ku, Sendai 980-8577, Japan, and Department of
| | - Yoshiteru Sakata
- Department of Material and Life Science, Graduate School of Engineering, Osaka University, CREST, Japan Science and Technology Corporation (JST), Suita, Osaka 565-0871, Japan, and The Institute of Scientific and Industrial Research, Osaka University, 8-1 Mihoga-oka, Ibaraki, Osaka 567-0047, Japan, and Institute for Multidisciplinary Research for Advanced Materials, Tohoku University, CREST, Japan Science and Technology Corporation (JST), Katahira, Aoba-ku, Sendai 980-8577, Japan, and Department of
| | - Shunichi Fukuzumi
- Department of Material and Life Science, Graduate School of Engineering, Osaka University, CREST, Japan Science and Technology Corporation (JST), Suita, Osaka 565-0871, Japan, and The Institute of Scientific and Industrial Research, Osaka University, 8-1 Mihoga-oka, Ibaraki, Osaka 567-0047, Japan, and Institute for Multidisciplinary Research for Advanced Materials, Tohoku University, CREST, Japan Science and Technology Corporation (JST), Katahira, Aoba-ku, Sendai 980-8577, Japan, and Department of
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Tavernier HL, Laine F, Fayer MD. Photoinduced Intermolecular Electron Transfer in Micelles: Dielectric and Structural Properties of Micelle Headgroup Regions. J Phys Chem A 2001. [DOI: 10.1021/jp0106597] [Citation(s) in RCA: 50] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- H. L. Tavernier
- Department of Chemistry, Stanford University, Stanford, California 94305
| | - Florence Laine
- Department of Chemistry, Stanford University, Stanford, California 94305
| | - M. D. Fayer
- Department of Chemistry, Stanford University, Stanford, California 94305
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Tyson DS, Luman CR, Zhou X, Castellano FN. New Ru(II) chromophores with extended excited-state lifetimes. Inorg Chem 2001; 40:4063-71. [PMID: 11466069 DOI: 10.1021/ic010287g] [Citation(s) in RCA: 145] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
We describe the synthesis, electrochemical, and photophysical properties of two new luminescent Ru(II) diimine complexes covalently attached to one and three 4-piperidinyl-1,8-naphthalimide (PNI) chromophores, [Ru(bpy)(2)(PNI-phen)](PF(6))(2) and [Ru(PNI-phen)(3)](PF(6))(2), respectively. These compounds represent a new class of visible light-harvesting Ru(II) chromophores that exhibit greatly enhanced room-temperature metal-to-ligand charge transfer (MLCT) emission lifetimes as a result of intervening intraligand triplet states ((3)IL) present on the pendant naphthalimide chromophore(s). In both Ru(II) complexes, the intense singlet fluorescence of the pendant PNI chromophore(s) is nearly quantitatively quenched and was found to sensitize the MLCT-based photoluminescence. Excitation into either the (1)IL or (1)MLCT absorption bands results in the formation of both (3)MLCT and (3)IL excited states, conveniently monitored by transient absorption and fluorescence spectroscopy. The relative energy ordering of these triplet states was determined using time-resolved emission spectra at 77 K in an EtOH/MeOH glass where dual emission from both Ru(II) complexes was observed. Here, the shorter-lived higher energy emission has a spectral profile consistent with that typically observed from (3)MLCT excited states, whereas the millisecond lifetime lower energy band was attributed to (3)IL phosphorescence of the PNI chromophore. At room temperature the data are consistent with an excited-state equilibrium between the higher energy (3)MLCT states and the lower energy (3)PNI states. Both complexes display MLCT-based emission with room-temperature lifetimes that range from 16 to 115 micros depending upon solvent and the number of PNI chromophores present. At 77 K it is apparent that the two triplet states are no longer in thermal equilibrium and independently decay to the ground state.
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Affiliation(s)
- D S Tyson
- Department of Chemistry and Center for Photochemical Sciences, Bowling Green State University, Bowling Green, Ohio 43403, USA
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