Transition-metal complexes of pyrrole pigments. Part VII. Cobalt(II) and zinc(II) chelates of some tripyrrene-b and bilene-b ligands

Abstract

The cobalt(II) and zinc(II) chelates of 1′,6-diethoxycarbonyl-1,2,3,4,5,6′-hexamethyitripyrrene-b and 1,19-di-ethoxycarbonyl-2,3,7,8,12,13,17,18-octamethyl-1,19-dideoxybilene-b in a ligand to metal ratio of 2:1 were prepared and investigated by electronic, i.r., and n.m.r. spectroscopy. A co-ordination geometry close to a regular tetrahedron (D₂ symmetry) around the metal atoms was assigned to these chelates.