E. Bayer, E. G. Witte
Jul 1, 1977
Citations
0
Influential Citations
10
Citations
Journal
Journal of Coordination Chemistry
Abstract
Abstract The preparation of cis- and trans-1,2-bis(2-pyridyl)-ethylene (BPE) is described and the different coordination behavior of the two isomers on the basis of their complexes with nickel(II) and zinc(II) are discussed. Fourteen new complexes have been prepared and characterized utilizing electronic spectra, vibrational spectra (conventional and far-infrared), magnetism, electrolytic conductance, and thermal analysis. Eleven further complexes could be detected by thermal analysis. Whereas zinc complexes of both ligands are tetrahedral, the nickel complexes of trans-BPE are planar and octahedral, those of cis-BPE tetrahedral, square-planar and five-coordinate. In chloroform solution the dissociation equilibrium Ni(cis-BPE)2Cl2 (five-coordinate) ⇋ Ni(cis-BPE)Cl2 (tetrahedral) + cis-BPE was studied spectrophotometrically. By the addition of methanol to cis-BPE complexes under mild conditions, tetragonal 1,2-bis(2-pyridyl)ethyl-methylether complexes are obtained.