Ligand-localised oxidation of a 4,4'-bipyridyl-bridged diruthenium(II) carbonyl catecholate complex

Article abstract of DOI:10.1016/0022-328X(91)86483-7

The reaction of <2> (6) with 4,4'-bipyridyl (4,4'-bipy) gives <2(μ-L)> (5, L = 4,4'-bipy) cyclic voltammetry and coulometry on which show a single two-electron oxidation process at a platinum electrode in CH2Cl2.The reaction of 5 (L = 4,4'-bipy) with yields the bis(o-benzosemiquinone) complex (5²⁺, L = 4,4'-bipy) via localised, catecholate ligand-based oxidation at the two independent sites.The pyrazine-bridged analogue (5²⁺, L = pyz) is prepared directly from 6, pyz, and .The intermediatemonocations 5⁺, the expected conproportionation products of the reactions between 5 and 5²⁺, have not been detected by spectroscopic (ESR, UV-VIS, IR) or cyclic voltammetric methods and have, by implication, localised electronic structures.