The thermodynamic stability of the mixed valence (one electron reduced) state between linked Ru3 units was studied by means of electrochemical methods for the series of the ligand-bridged triruthenium cluster dimer, [Ru3(μ-O)(n-CH3CO2) 6(CO)(L)(n-BL)Ru3(μ-O)(μ-CH3CO 2)6(CO)(L)] (BL = 1,4-pyrazine: L = 4-dimethylaminopyridine (dmap) (1a), pyridine (py) (1b), 4-cyanopyridine (cpy) (1e), 1-azabicyclo[2.2.2]octane (1d); BL = 4,4′-bipyridine: L = dmap (2a), py (2b), cpy (2c); BL = 2,7-diazapyrene: L = dmap (3a); BL = 1,4-diazabicyclo[2.2.2]octane: L = dmap (4a), py (4b), cpy (4c)). The mixed valence states undergoing rapid intramolecular electron transfers were observed by ER spectroelectrochemistry. By simulating dynamical effects on the observed v(CO) absorption bandshapes, the rate constants ke for electron transfer in the mixed valence states of la, Ib, le and Id were estimated to be 9×1011 s-1 (at room temperature (rt)), 5×1011 s-1 (at it), c.a,1×1011 s-1 (at it), and 1×1012 s-1 (at-18 °C), respectively. Possible applications of this approach to asymmetric mixed valence systems were discusssed.
|ジャーナル||Materials Science- Poland|
|出版ステータス||Published - 2003 12月 1|
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