Philip S. Bryan

COPPER(II) COMPLEXES OF BIS-2,6-(METHYLTHIOMETHYL) PYRIDINE AND THE DITHIA(2,6)PYRIDINOPHANES

Abstract A series of tridentate macrocycles, the dithia(2,6)pyridinophanes, react with copper(II) to form five coordinate complexes of the form [Cu(tridentate)X2] where X=Cl−, Br−, or NCS−. Available evidence suggests that 2,9-dithia[10] (2,6)pyridinophane coordinates in a folded manner while it is uncertain whether 2,10-dithia[11](2,6)pyridinophane and 2,11-dithia[12](2,6)pyridinophane coordinate in a folded or a planar fashion. These geometries result from the presence of varying lengths of the non-coordinating methylene chain present in each macrocycle. The effect of the methylene bridge on the structure and stability of the various complexes is discussed. The acyclic analogue, bis-2,6(methylthiomethyl)pyridine, also forms pentacoordinate complexes of the type [Cu(tridentate)X2] as well as 2:1 ligand to metal complexes, [Cu(tridentate)2](BF4), Electronic spectra of the latter complex indicate that the copper(II) is in a slightly distorted octahedral environment in the solid state.