Variation of product identity as a function of metal ion: ligand reaction ratio, stereochemical studies and thermal investigation of Mn(II), Fe(III), N

Abstract

A systematic investigation of the MX 2 and FeCl 3/APH reaction systems in EtOH is described, where M = Mn, Ni, Cu, Cd and Hg, X = Cl, Br, NO 3, SCN, CH 3COO, BF 4 and 1 2 SO 4, and APH = 2-acetylpyridine hydrazone. Emphasis has been placed on determining the influence of the metal ion : APH ratio on the identity of the reaction products. The variation of this ratio has led to the synthesis of thirty-two new discrete complexes with general compositions M(APH)X 2, M(APH) 2X 2, M(APH) 3X 2, Fe(APH)Cl 3 and Fe(APH) 2Cl 3. The complexes were characterized by elemental analyses, conductivity measurements. X-ray powder patterns, thermal methods, magnetic susceptibilities and spectroscopie (IR, ligand field, 1H NMR, ESR) studies. Monomeric pseudo-tetrahedral and monomeric or polymeric distorted octahedral stereochemistries were assigned in the solid state. APH appears to coordinate via both the pyridine and methine nitrogen atoms. The thermal decomposition of the prepared complexes was also studied. Some Ni(II) complexes decompose via stable intermediates. Probable mechanistic paths of the decomposition reactions have been proposed.