Bistridentate Ruthenium(II)polypyridyl-Type Complexes with Microsecond (MLCT)-M-3 State Lifetimes: Sensitizers for Rod-Like Molecular Arrays
(2008) In Journal of the American Chemical Society 130(46). p.15533-15542- Abstract
- A series of bistridentate ruthenium(II) polypyridyl-type complexes based on the novel 2,6-di(quinolin-8-yl)pyridine (dqp) ligand have been synthesized and their photophysical properties have been studied. The complexes are amenable to substitution in the 4-position of the central pyridine with conserved quasi-C-2v symmetry, which allows for extension to isomer-free, rod-like molecular arrays for vectorial control of electron and energy transfer. DIFT calculations performed on the parent [Ru(dqp)(2)](2+) complex (1) predicted a more octahedral structure than in the typical bistridentate complex [Ru(tpy)(2)](2+) (tpy is 2,2':6',2 ''-terpyridine) thanks to the larger ligand bite angle, which was confirmed by X-ray crystallography. A strong... (More)
- A series of bistridentate ruthenium(II) polypyridyl-type complexes based on the novel 2,6-di(quinolin-8-yl)pyridine (dqp) ligand have been synthesized and their photophysical properties have been studied. The complexes are amenable to substitution in the 4-position of the central pyridine with conserved quasi-C-2v symmetry, which allows for extension to isomer-free, rod-like molecular arrays for vectorial control of electron and energy transfer. DIFT calculations performed on the parent [Ru(dqp)(2)](2+) complex (1) predicted a more octahedral structure than in the typical bistridentate complex [Ru(tpy)(2)](2+) (tpy is 2,2':6',2 ''-terpyridine) thanks to the larger ligand bite angle, which was confirmed by X-ray crystallography. A strong visible absorption band, with a maximum at 491 nm was assigned to a metal-to-ligand charge transfer (MLCT) transition, based on time-dependent DIFT calculations. 1 shows room temperature emission (Phi = 0.02) from its lowest excited ((MLCT)-M-3) state that has a very long lifetime (tau = 3 mu s). The long lifetime is due to a stronger ligand field, because of the more octahedral structure, which makes the often dominant activated decay via short-lived metal-centered states insignificant also at elevated temperatures. A series of complexes based on dqp with electron donating and/or accepting substituents in the 4-position of the pyridine was prepared and the properties were compared to those of 1. An unprecedented (MLCT)-M-3 state lifetime of 5.5 mu s was demonstrated for the homoleptic complex based on dqpCO(2)Et. The favorable photosensitizer properties of 1, such as a high extinction coefficient, high excited-state energy and long lifetime, and tunable redox potentials, are maintained upon substitution. In addition, the parent complex 1 is shown to be remarkably photostable and displays a high reactivity in light-induced electron and energy transfer reactions with typical energy and electron acceptors and donors: methylviologen, tetrathiofulvalene, and 9,10-diphenylanthracene. This new class of complexes constitutes a promising starting point for the construction of linear, rod-like molecular arrays for photosensitized reactions and applications in artificial photosynthesis and molecular electronics. (Less)
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https://lup.lub.lu.se/record/1457471
- author
- Abrahamsson, Maria ; Jager, Michael ; Kumar, Rohan J. ; Österman, Tomas LU ; Persson, Petter LU ; Becker, Hans-Christian ; Johansson, Olof and Hammarstrom, Leif
- organization
- publishing date
- 2008
- type
- Contribution to journal
- publication status
- published
- subject
- in
- Journal of the American Chemical Society
- volume
- 130
- issue
- 46
- pages
- 15533 - 15542
- publisher
- The American Chemical Society (ACS)
- external identifiers
-
- scopus:56449129009
- wos:000263311300058
- ISSN
- 1520-5126
- DOI
- 10.1021/ja804890k
- language
- English
- LU publication?
- yes
- additional info
- The information about affiliations in this record was updated in December 2015. The record was previously connected to the following departments: Chemical Physics (S) (011001060)
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- 5e5a707d-14ac-481f-851a-80dd823aec38 (old id 1457471)
- date added to LUP
- 2016-04-01 14:36:37
- date last changed
- 2022-04-06 19:34:42
@article{5e5a707d-14ac-481f-851a-80dd823aec38,
abstract = {{A series of bistridentate ruthenium(II) polypyridyl-type complexes based on the novel 2,6-di(quinolin-8-yl)pyridine (dqp) ligand have been synthesized and their photophysical properties have been studied. The complexes are amenable to substitution in the 4-position of the central pyridine with conserved quasi-C-2v symmetry, which allows for extension to isomer-free, rod-like molecular arrays for vectorial control of electron and energy transfer. DIFT calculations performed on the parent [Ru(dqp)(2)](2+) complex (1) predicted a more octahedral structure than in the typical bistridentate complex [Ru(tpy)(2)](2+) (tpy is 2,2':6',2 ''-terpyridine) thanks to the larger ligand bite angle, which was confirmed by X-ray crystallography. A strong visible absorption band, with a maximum at 491 nm was assigned to a metal-to-ligand charge transfer (MLCT) transition, based on time-dependent DIFT calculations. 1 shows room temperature emission (Phi = 0.02) from its lowest excited ((MLCT)-M-3) state that has a very long lifetime (tau = 3 mu s). The long lifetime is due to a stronger ligand field, because of the more octahedral structure, which makes the often dominant activated decay via short-lived metal-centered states insignificant also at elevated temperatures. A series of complexes based on dqp with electron donating and/or accepting substituents in the 4-position of the pyridine was prepared and the properties were compared to those of 1. An unprecedented (MLCT)-M-3 state lifetime of 5.5 mu s was demonstrated for the homoleptic complex based on dqpCO(2)Et. The favorable photosensitizer properties of 1, such as a high extinction coefficient, high excited-state energy and long lifetime, and tunable redox potentials, are maintained upon substitution. In addition, the parent complex 1 is shown to be remarkably photostable and displays a high reactivity in light-induced electron and energy transfer reactions with typical energy and electron acceptors and donors: methylviologen, tetrathiofulvalene, and 9,10-diphenylanthracene. This new class of complexes constitutes a promising starting point for the construction of linear, rod-like molecular arrays for photosensitized reactions and applications in artificial photosynthesis and molecular electronics.}},
author = {{Abrahamsson, Maria and Jager, Michael and Kumar, Rohan J. and Österman, Tomas and Persson, Petter and Becker, Hans-Christian and Johansson, Olof and Hammarstrom, Leif}},
issn = {{1520-5126}},
language = {{eng}},
number = {{46}},
pages = {{15533--15542}},
publisher = {{The American Chemical Society (ACS)}},
series = {{Journal of the American Chemical Society}},
title = {{Bistridentate Ruthenium(II)polypyridyl-Type Complexes with Microsecond (MLCT)-M-3 State Lifetimes: Sensitizers for Rod-Like Molecular Arrays}},
url = {{http://dx.doi.org/10.1021/ja804890k}},
doi = {{10.1021/ja804890k}},
volume = {{130}},
year = {{2008}},
}