Tris(6,6′-diamino-2,2′-bipyridine)ruthenium(II): Effect of High Interligand Steric Strain on the Structure

Abstract

Abstract A series of the ruthenium(II) complexes 1–4, [Ru(dabp)3−n(bpy)n](BF4)2 (n=0, 1, 2, and 3, respectively, dabp=6,6′-diamino-2,2′-bipyridine, and bpy=2,2′-bipyridine), having a different degree of interligand steric strain were synthesized, and the effect of the interligand steric strain caused by the amino substituents on their structures was examined. A crystallographic study showed that the two pyridine rings of dabp in the complex 1 were in a slightly twisted configuration in order to relieve the interligand strain. Similar twisted configurations were suggested for the bipyridine moieties of dabp and bpy in the complexes 1–3 in dimethyl sulfoxide solution.