Preparation, Characterization, Redox Properties, and UV−Vis−NIR Spectra of Binuclear Ruthenium Complexes [{(Phtpy)(PPh<sub>3</sub>)<sub>2</sub>Ru}<sub>2</sub>{C⋮C−(CHCH)<i><sub>m</sub></i>−C⋮C}]<i><sup>n</sup></i><sup>+</sup> (Phtpy = 4‘-phenyl-2,2‘:6‘,2‘ ‘-terpyridine)
作者:Li-Bin Gao、Sheng-Hua Liu、Li-Yi Zhang、Lin-Xi Shi、Zhong-Ning Chen
DOI:10.1021/om050765l
日期:2006.1.1
A series of C-4-C-10 bridged Ru-2(II,II) complexes [(Phtpy)(PPh3)(2)Ru}(2)(C C-(CH=CH)(m)-C C)](2+) (m 0, 1, 2, 3) were prepared by reaction of [(Phtpy)(PPh3)(2)Ru(acetone)](2+) With Me3Si-C C-(CH=CH)(m)-C C)](3+) in the presence of potassium fluoride. Oxidation of the Ru-2(II,II) of ferrocenium hexafluorophosphate gave the stable Ru-2(II,III) mixed-valence complexes [(Phtpy)(PPh3)2Ru}(2)(C C-(CH=CH)(m)-C C)](3+) when m = 0, 1, or 2. These complexes were all characterized by microanalyses, ESI-MS, 1H and P-31 NMR, IR, and UV-vis-NIR spectroscopy, cyclic and differential pulse voltammetry, and X-ray crystallography for compound [1](PF6)(2). The wave separations Delta E-1/2 (E-1/2(A) - E-1/2 B) due to stepwise oxidation of two Ru-II into Ru-III are 0.610, 0.260, 0.165, and < 0.070 V for m = 0-3, respectively, in dichloromethane solutions, revealing a significant dependence of the electronic communication on metal-metal distances. The visible-NIR spectral studies on the Ru-2(II,III) mixed-valence complexes [I(Phtpy)(PPh3)(2)Ru}(2)(C=C-(CH=CH),-C=C)III (m = 0, 1, 2) demonstrated that electronic delocalization along the molecular rods attenuates dramatically with the increase of the ethenyl number.