1-1 METAL-COMPLEXES OF 2-(2'-PYRIDYL)QUINOXALINE, A LIGAND UNEXPECTEDLY FORMED BY THE REACTION BETWEEN 2-ACETYLPYRIDINE AND 1,2-PHENYLENEDIAMINE

The complexes (MLCl2] (M=Co, Ni, Cu, Zn), where L is the new ligand 2- (2'-pyridyl)quinoxaline derived unexpectedly from 2-acetylpyridine and 1,2-phenylenediamine, were isolated. The ligand and its complexes hav e been characterized by a variety of physical and spectroscopic techni ques. L behaves as a bidentate chelating ligand in the monomeric pseud otetrahedral Zn(II) compound; all three nitrogen atoms of L are involv ed in coordination in the polymeric Co(II), Ni(II) and Cu(II) complexe s giving five-coordinate (Co(II)) or six-coordinate (Ni(II), Cu(II)) s tructures.