Optical Metal to Ligand Charge Transfer of 2,2'-Bipyridyl Complexes of Antimony(III) and Bismuth(III)

Abstract

The complexes [M(2,2′-bipyridyl)X3], with M = Sb, Bi and X = Cl, Br, I, are characterized by long-wavelength metal-to-ligand charge-transfer (MLCT) bands which determine the colours of these compounds in the solid state. The energy of the MLCT bands depends on the reducing strength of the metal and the extent of sp mixing of the lone electron pair at the metal.