Influence of the CN Orientation on the Degree of Electron Delocalization of Ru-Ru-Ru Mixed-Valent Complexes.

Investigations on mixed-valent complexes in the Class II/Class III frontier have been a particularly interesting issue due to their special electron delocalization. In this work, a pair of cyanidometal-/isocyanidometal-bridged Ru-Ru-Ru compounds, -[Cp(dppe)Ru-B-Ru(dppe)Cp] (B = NCRu(bpy)CN, ; B = CNRu(bpy)NC, ; Cp = 1,3-cyclopentadienyl, dppe = 1,2-bis(diphenlyphosphine)ethane, bpy = 2,2'-bipyridine), and one-electron oxidized and were synthesized and well characterized. For the two-electron oxidized and , their Fourier transform infrared (FTIR) and UV-vis-NIR spectra were investigated by employing spectroelectrochemical methods. The time-dependent density-functional theory (TDDFT) calculations and the experimental results indicate that the one-/two-electron oxidized mixed-valent compounds belong to Class II-III systems.