Mono- and Bi-nuclear Complexes of the Doubly Bidentate, Bridging Ligand 4,6-Di(2-pyridyl)pyrimidine.

Abstract

Thirteen mononuclear, homobinuclear and heterobinuclear transition metal complexes of 4,6-di(2- pyridyl)pyrimidine have been prepared. Assignments of the ¹H n.m.r. spectra of the molybdenum(0) and ruthenium(II) complexes were achieved by a combination of one- and two-dimensional n.m.r. techniques, especially 1D-TOCSY. For the ruthenium complexes, electronic absorption spectroscopy and cyclic voltammetry were used to probe the nature of the metal{ligand and, for the binuclear complexes, metal-metal interactions. The complexes have low HOMO−LUMO energy gaps. Meta-metal interactions are shown to be of similar magnitude to those in complexes of the better-studied ligands 2,2′-bipyrimidine and 2,3-di(2-pyridyl)pyrazine.