Structural and thermal study of asymmetric α-dioxime complexes of Co(III) with Cl and methyl-pyridines

• DOI: 10.1016/j.poly.2010.04.014
• Publication Date: 2010-04-28T09:07:40Z
• Authors: Imre Miklós Szilágyi; Andrea Deák; Csaba Várhelyi; János Madarász; György Pokol; Ágnes Gömöry; Csaba Várhelyi
• Keywords: 01 natural sciences; 0104 chemical sciences

Abstract Two new cobalt(III)-chelates, trans-bis(methyl-ethyl-dioximato)-chloro-β-picoline-cobalt (III) (1), and trans-bis(methyl-ethyl-dioximato)-chloro-3,4-lutidine-cobalt (III) (2) were obtained by oxidizing a mixture of CoCl2, methyl-ethyl-dioxime and amines: β-picoline (3-methyl-pyridine) for (1) and 3,4-lutidine (3,4-dimethyl-pyridine) for (2). The crystal structure of (1) was determined by single crystal XRD (monoclinic, space group P21/c (No. 14) with a = 8.391(3) A, b = 14.421(5) A, c = 18.383(8) A, β = 114.57(2)°, R = 0.0499), while both (1) and (2) were studied by middle and far FTIR spectroscopy, electrospray ionization (ESI) MS, powder XRD and thermal analysis (TG/DTA-MS). Melting of the related complexes 1 and 2 at 219 and 184 °C, respectively, results in an immediate chemical degradation of their whole structure and tarring of ligands.