Synthesis and characterisation of a pair of azo anion radicals bonded to ruthenium(ii)

Abstract

The reactions of 1-methyl-2-(p-chlorophenylazo)imidazole (L¹) and 2-(phenylazo)pyridine (L²) with [Ru(H)(X)- (CO)(PPh₃)₃] (X = Cl, Br) have afforded the green paramagnetic (S = ½) and EPR-active (g ≈ 2.00) title anion radical complexes [Ru(L^1·–)(Cl)(CO)(PPh₃)₂] 1 and [Ru(L^2·–)(Br)(CO)(PPh₃)₂] 2 in which the N–N bond lengths lie near 1.35 Å.