PREPARATION AND REACTIVITY OF METAL-CONTAINING MONOMERS .25. SYNTHESIS AND SPATIAL AND ELECTRONIC-STRUCTURE OF COMPLEXES OF CHROMIUM(III), NICKEL(II) AND COBALT(II) CHLORIDES WITH NITROGEN-CONTAINING VINYLHETEROCYCLES

Metal-containing monomers based on vinyl derivatives of heterocycles (4-vinylpyridine, 3,5-dimethyl-1-vinylpyrazole, 2-methyl-5-vinyltetrazole) and NiCl2, CoCl2, CrCl3 have been prepared and characterized by chemical analysis, IR and electron spectroscopy. By means of spectral methods, the complex formation has been shown to involve N atom of the heterocycle, while the exocyclic C = C bond does not participate in the process. The structure of polyhedrons formed has been characterized both in the solid state and in methanol or DMF. The comparison of splitting parameters for different symmetries indicates that in passing from five-membered to six-membered vinylheterocycles, the strength of the ligand field is greatly enhanced.