The properties of transition-metal complexes of dipyrromethenes. Part II. Dipyrromethenes as unidentate ligands
Abstract
Complexes of the form M(PMH)2X2 can be isolated where M = CuII, CoII, NiII, ZnII, or CdII; PMH = 4,4′-di-ethoxycarbonyl-3,3′,5,5′-tetramethyldipyrromethene and X = Cl–, Br–, I–, CNS–, or NO3–. The presence of N–H bonds can be detected spectroscopically, indicating that co-ordination occurs through the basic pyrrole nitrogen. A number of the Cu, Ni, and Co complexes behave as 1:1 electrolytes in acetone. Magnetic and spectral results suggest tetrahedral structures for the cobalt and possibly nickel complexes.