Efficient Energy Conversion in Photochromic Ruthenium DMSO Complexes
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- 作者：Aaron A. Rachford ; Jeffrey L. Petersen ; and Jeffrey J. Rack
- 刊名：Inorganic Chemistry
- 出版年：2006
- 出版时间：July 24, 2006
- 年：2006
- 卷：45
- 期：15
- 页码：5953 - 5960
- 全文大小：169K
- 年卷期：v.45,no.15(July 24, 2006)
- ISSN：1520-510X
文摘
The photochromic compounds trans- and cis-[Ru(tpy)(Mepic)(dmso)](OSO2CF3) (2 and 3, respectively; tpy is 2,2':6',2' '-terpyridine; Mepic is 6-methyl-2-pyridinecarboxylate; dmso is dimethyl sulfoxide) and cis-[Ru(tpy)(Brpic)(dmso)](PF6) (4; Brpic is 6-bromo-2-pyridinecarboxylate) were prepared and characterized by single-crystal X-raycrystallography, electrochemistry, NMR, IR, and UV-vis spectroscopy. The geometry labels refer to the relationshipbetween the carboxylate oxygen of the picolinate ligand and dmso. Electrochemical studies reveal that only thetrans isomer shows S-to-O isomerization following oxidation of Ru(II) and O-to-S isomerization following reductionof Ru(III). The cis isomers of both complexes feature reversible one-electron Ru(III/II) couples. All complexes undergophototriggered S-to-O isomerization following MLCT (metal-to-ligand charge transfer) excitation with quantum yields(
S
O) of 0.79 (2), 0.011 (3), and 0.014 (4). The methyl group in 2 promotes isomerization by hindering rotationof the dmso ligand about the Ru-S bond. Computational results support this role for the methyl group. Relativeenergy calculations show that the barrier to rotation is approximately 8 kcal mol-1. These results suggest thatrotation is an important vibration for isomerization in photochromic ruthenium-dmso complexes.
SO) of 0.79 (2), 0.011 (3), and 0.014 (4). The methyl group in 2 promotes isomerization by hindering rotationof the dmso ligand about the Ru-S bond. Computational results support this role for the methyl group. Relativeenergy calculations show that the barrier to rotation is approximately 8 kcal mol-1. These results suggest thatrotation is an important vibration for isomerization in photochromic ruthenium-dmso complexes.