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Title: Structure and redox and photophysical properties of a series of ruthenium heterocycles based on the ligand 2,3-bis(2-pyridyl)quinoxaline

Abstract

The synthesis, structure, and redox and photophysical properties of (Ru(bpy)/sub n/(BL)/sub 3-n/)/sup 2 +/, where n = 0-2, bpy is 2,2'-bipyridine, and BL is 2,3-bis(2-pyridyl)quinoxaline, are described. The (Ru(bpy)/sub 2/(BL))(PF/sub 6/)/sub 2/ complex crystallized in the monoclinic space group P2/sub 1//a and the cell parameters are repeated. All non-H atoms were refined anisotropically to an R value of 0.0672 for 5766 reflections with I > sigma(I). The ruthenium to nitrogen bond distances were Ru-N(pyridine) = 2.06 A (average) and Ru-N(pyrazine) = 2.096 (4) A. Absorption spectra contained bands (250-300 nm) in the ultraviolet region that were assignable to ligand ..pi.. ..-->.. ..pi..* transitions and visible bands (517-300 nm) that were assignable to d..pi.. ..-->.. ..pi..* MLCT transitions. Reduction potentials for the Ru/sup 3+/2+/ couples varied from about 1.40 to 1.70 V vs SSCE. Three reductions were observed and assigned to the one-electron reduction of each bidentate ligand. Weak luminescence was observed, and corrected emission energy maxima were located at 766 +/- 4 nm. Excited-state reduction potentials were estimated from the difference between emission energy maxima and ground-state reduction potentials. Excited-state lifetimes at room temperature in 4:1 EtOH-MeOH ranged from 167 to < 70 ns. Temperature-dependent-lifetime (90-298 K) data gave evidencemore » for ..delta..E' values of 1100 +/- 300 cm/sup -1/. The temperature dependence was attributed to either the third MLCT state according to the localized-orbital model or the presence of a fourth CT state for (Ru(BL)/sub 2/(bpy))/sup 2 +/, since little photochemistry was found for it, and to the third and/or the fourth CT state and the dd state for both (Ru(BL)/sub 2/(bpy))/sup 2 +/ and (Ru(BL)/sub 3/)/sup 2 +/. 54 references, 7 figures, 6 tables.« less

Authors:
; ; ; ; ; ;
Publication Date:
Research Org.:
Univ. of North Carolina, Charlotte
OSTI Identifier:
6808718
DOE Contract Number:  
AC05-84OR21400
Resource Type:
Journal Article
Journal Name:
Inorg. Chem.; (United States)
Additional Journal Information:
Journal Volume: 26:4
Country of Publication:
United States
Language:
English
Subject:
37 INORGANIC, ORGANIC, PHYSICAL AND ANALYTICAL CHEMISTRY; 14 SOLAR ENERGY; BIPYRIDINES; CRYSTAL STRUCTURE; PHOTOCHEMISTRY; REDOX REACTIONS; ORGANOMETALLIC COMPOUNDS; RUTHENIUM COMPLEXES; EXPERIMENTAL DATA; AZINES; CHEMICAL REACTIONS; CHEMISTRY; COMPLEXES; DATA; HETEROCYCLIC COMPOUNDS; INFORMATION; NUMERICAL DATA; ORGANIC COMPOUNDS; ORGANIC NITROGEN COMPOUNDS; PYRIDINES; TRANSITION ELEMENT COMPLEXES; 400201* - Chemical & Physicochemical Properties; 400500 - Photochemistry; 140505 - Solar Energy Conversion- Photochemical, Photobiological, & Thermochemical Conversion- (1980-)

Citation Formats

Rillema, D P, Taghdiri, D G, Jones, D S, Keller, C D, Worl, L A, Meyer, T J, and Levy, H A. Structure and redox and photophysical properties of a series of ruthenium heterocycles based on the ligand 2,3-bis(2-pyridyl)quinoxaline. United States: N. p., 1987. Web. doi:10.1021/ic00251a018.
Rillema, D P, Taghdiri, D G, Jones, D S, Keller, C D, Worl, L A, Meyer, T J, & Levy, H A. Structure and redox and photophysical properties of a series of ruthenium heterocycles based on the ligand 2,3-bis(2-pyridyl)quinoxaline. United States. https://doi.org/10.1021/ic00251a018
Rillema, D P, Taghdiri, D G, Jones, D S, Keller, C D, Worl, L A, Meyer, T J, and Levy, H A. Wed . "Structure and redox and photophysical properties of a series of ruthenium heterocycles based on the ligand 2,3-bis(2-pyridyl)quinoxaline". United States. https://doi.org/10.1021/ic00251a018.
@article{osti_6808718,
title = {Structure and redox and photophysical properties of a series of ruthenium heterocycles based on the ligand 2,3-bis(2-pyridyl)quinoxaline},
author = {Rillema, D P and Taghdiri, D G and Jones, D S and Keller, C D and Worl, L A and Meyer, T J and Levy, H A},
abstractNote = {The synthesis, structure, and redox and photophysical properties of (Ru(bpy)/sub n/(BL)/sub 3-n/)/sup 2 +/, where n = 0-2, bpy is 2,2'-bipyridine, and BL is 2,3-bis(2-pyridyl)quinoxaline, are described. The (Ru(bpy)/sub 2/(BL))(PF/sub 6/)/sub 2/ complex crystallized in the monoclinic space group P2/sub 1//a and the cell parameters are repeated. All non-H atoms were refined anisotropically to an R value of 0.0672 for 5766 reflections with I > sigma(I). The ruthenium to nitrogen bond distances were Ru-N(pyridine) = 2.06 A (average) and Ru-N(pyrazine) = 2.096 (4) A. Absorption spectra contained bands (250-300 nm) in the ultraviolet region that were assignable to ligand ..pi.. ..-->.. ..pi..* transitions and visible bands (517-300 nm) that were assignable to d..pi.. ..-->.. ..pi..* MLCT transitions. Reduction potentials for the Ru/sup 3+/2+/ couples varied from about 1.40 to 1.70 V vs SSCE. Three reductions were observed and assigned to the one-electron reduction of each bidentate ligand. Weak luminescence was observed, and corrected emission energy maxima were located at 766 +/- 4 nm. Excited-state reduction potentials were estimated from the difference between emission energy maxima and ground-state reduction potentials. Excited-state lifetimes at room temperature in 4:1 EtOH-MeOH ranged from 167 to < 70 ns. Temperature-dependent-lifetime (90-298 K) data gave evidence for ..delta..E' values of 1100 +/- 300 cm/sup -1/. The temperature dependence was attributed to either the third MLCT state according to the localized-orbital model or the presence of a fourth CT state for (Ru(BL)/sub 2/(bpy))/sup 2 +/, since little photochemistry was found for it, and to the third and/or the fourth CT state and the dd state for both (Ru(BL)/sub 2/(bpy))/sup 2 +/ and (Ru(BL)/sub 3/)/sup 2 +/. 54 references, 7 figures, 6 tables.},
doi = {10.1021/ic00251a018},
url = {https://www.osti.gov/biblio/6808718}, journal = {Inorg. Chem.; (United States)},
number = ,
volume = 26:4,
place = {United States},
year = {1987},
month = {2}
}