NOVEL TETRA-DENTATE AND HEXA-DENTATE LIGANDS FROM 6,6'-DICYANO-2,2'-BIPYRIDINE

A simple, direct route from 2,2'-bipyridine to 6,6'-dicyano-2,2'-bipyridine and its conversion to the 6,6'-dithiocarboxamide and various novel tetra- and hexa-dentate ligands such as the 6,6'-bis(4-methyl-thiazol-2-yl) and 6,6'-bis[4-(2-pyridyl)thiazol-2-yl] derivatives have been established. Diaqua[6,6'-bis(4-methylthiazol-2-yl)-2,2'-bipyridine]zinc(II) bis(trifluoromethanesulfonate) has been prepared and its crystal structure determined. The tetra-heterocyclic ligand is planar, binding through two bipyridine nitrogen atoms and, more weakly, through two thiazolyl nitrogen atoms to zinc(ii) which is in a distorted octahedral environment.