{(μ-L)[Ru II (acac) 2 ] 2 } n , n = 2+, +, 0, −, 2−, with L = 3,3′,4,4′-tetraimino-3,3′,4,4′-tetrahydrobiphenyl. EPR-supported assignment of NIR absorptions for the paramagnetic intermediates

A complete EPR and UV-Vis-NIR spectroelectrochemical characterisation has been carried out for the series 1(2+/+/0/-/2-) where is the 1 new complex [(mu-L)[Ru(II)(acac)2]2], L = 3,3',4,4'-tetraimino-3,3',4,4'-tetrahydrobiphenyl. The paramagnetic intermediates are identified as the anion radical (L*-) complex 1*- with a long-wavelength intra-ligand transition at 2160 nm and as the weakly coupled diruthenium(II,III) species 1+ (Kc= 10(3)) with a low-intensity intervalence charge transfer (IVCT) band at 1570 nm. DFT calculations using ADF and Gaussian 03 programs support these assignments.