Copper(II) coordination compounds with ferulic acid

摘要

The first two molecular structures of the ferulic acid (3-(4-hydroxy-3-methoxyphenyl)-2-propenoic acid, C10H10O4) coordination compounds are presented, namely, [Cu-2(C10H9O4)(4)(CH3CN)(2)] 1 and [Cu-2(C10H9O4)(4)(C6H6N2O)(2)]center dot 4CH(3)CN (C6H6N2O=nicotinamide) 2. Both compounds were synthesised from the starting mixture Of Cu2O and CuCl upon copper oxidation in the acetonitrile solution. The single-crystal X-ray diffraction analysis of 1 and 2 reveals the binuclear structure of the 'paddle-wheel' type for both complexes. 1 and 2 are unstable outside mother liquid due to loosely bound acetonitrile molecules. The final products of decomposition are [Cu-2(C10H9O4)(4)] 1a and [Cu-2(C10H9O4)(4)(C6H6N2O)(2)] 2a, which were characterized by several physico-chemical methods. The triplet X-band EPR spectra of la and 2a, showing signals B-Z1 similar to 15 mT, B-perpendicular to 2 similar to 460 mT and B-Z2 - 580 mT, are in agreement with the expected data for the binuclear tetracarboxylate units, found in the structures of the parent complexes I and 2. Together with the room temperature magnetic susceptibility data, mu(eff)/B.M. 1.40 (1a), 1.48 (2a), the EPR spectra analysis confirm the anti ferromagnetic interaction in la and 2a. This is suggesting preservation and stability of the paddle-wheel structures in la and 2a.