Transition-metal complexes of the 2,3-dipyridylquinoxalines. Part I. Cobalt(II), nickel(II), and copper(II) halide derivatives of 2,3-di-(2-pyridyl)quinoxaline

Abstract

The cobalt(II), nickel(II), and copper(II) halide complexes of 2,3-di-(2-pyridyl)quinoxaline are described, and the structures interpreted on the basis of magnetic and spectral data. For cobalt, the tetrahedral complexes CoX₂(DPYQ) where X = Cl and Br, and CoX₂(DPYQ)₂ where X = Br and I, were isolated. For copper both the chloro- and bromo-complexes have stoicheiometry CuX₂(DPYQ), though with different structures. The nickel complexes follow a less well ordered pattern, though both the complexes isolated pure, Ni₂Cl₄(DPYQ)(H₂O)₂ and NiBr₂(DPYQ), are believed to be octahedral.