Synthesis and Characterization of Cobalt Complexes of Heterocyclic Bidentate Ligands (N,X), X= S, Se

Abstract

The synthesis and structural characterization of a series of homoleptic cobalt complexes of general formula [Co(R-pyX) 3 ] is reported, where X ϭ S, Se; R ϭ H, 3-CF 3 and 5-CF 3 . The compounds were synthesized by electrochemical oxidation of the metal in a cell containing an acetonitrile solution of the corresponding ligand. When 2,2Ј-bipyridine (bipy) or 1,10-phenanthroline (phen) were added to the electrolytic cell, mixed cobalt(II) compounds [Co(R-pyX) 2 L] (L ϭ bipy, phen) were also isolated. All of the complexes obtained have been characterized by microanalysis, vibrational and electronic spectroscopy, FAB mass spectrometry * Professor Dr. M. L. Durán 1853 and, in the case of diamagnetic compounds that were sufficiently soluble, by 1 H and 13 C NMR spectroscopy. Crystals of [Co(3-CF 3 -pyS) 3 ] and [Co(5-CF 3 -pyS) 3 ] were obtained and studied by X-ray diffraction. The crystal structures consist of monomeric molecules with the metal atom in an octahedral environment and the ligands in a meridional disposition.

Synthesis, structure and magnetic properties of copper(II) complexes of 2-amino-5-trifluoromethylpyridine (5-TFMAP): (5-TFMAP)2CuX2 (X=Cl or Br), (5-TFMAP)3CuBr2 and [(5-TFMAP)2CuBr2](5-TFMAPH)Br

“…The tendency of CF 3 groups to cluster has been observed previously in such complexes as (3-CF 3 py) 2 ZnBr 2 [29] and (5-CF 3 pyridine-2-thiolate) 3 Co [30]. Even the corresponding salts of 5-TFMAP, (5-TFMAPH) 2 CuX 4 [16] show the same type of aggregation ( Fig.…”