Synthesis and structural characterization of copper(I), silver(I) and gold(I) complexes with pyrimidine-2-thionato ligands and their adducts with phosphanes

Abstract

Homoleptic copper and silver compounds of a series of pyrimidine-2-thionato derivatives (RpymS-; R = 4,6-Me2,5-Et; 4-CF3; 4,6-CF3,Ph) have been synthesized by electrochemical oxidation of anodic metal (copper or silver) in a cell containing an acetonitrile solution of the appropriate thione and a small amount of tetraethylammonium perchlorate as electrolytic carrier. Subsequent reaction of these pyrimidine-2-thionato compounds with triphenylphosphane or bis(diphenylphosphanyl)methane (dppm) in acetonitrile allowed the synthesis of the corresponding heteroleptic complexes. The reaction of [Au(PPh3)Cl] with the corresponding pyrimidine-2-thione in ethanol in the presence of triethylamine gave [Au(4,6-Me2,5-EtpymS)(PPh3)] and [Au(4-CF 3pymS)(PPh3)] in good yields. The compounds were characterized by microanalysis, IR spectroscopy, FAB-MS and, when sufficientlysoluble, 1H, 13C and 31P NMR spectroscopy. Compounds [Cu6(4,6-CF3PhpymS)6] (1), [Ag6(4,6-Me2,5-EtpymS)6] ·2MeOH·3H2O (2), [Cu2(4-CF 3pymS)2(dppm)2]·2CH3CN (3), [Cu(4-CF3pymS)(PPh3)2] (4) and [Au(4-CF 3pymS)(PPh3)] (5) were also characterized by X-ray diffraction. Electrochemical oxidation of anodic metal (copper or silver) in a cell containing asubstituted pyrimidine-2-thione and acetonitrile affords homoleptic complexes [M(RpymS)]. The reactions of these homoleptic complexes with phosphanes yield heteroleptic complexes. Mixed gold(I) complexes were also easily prepared by reaction between the corresponding thione and the precursor [AuCl(PPh3)]. Copyright © 2011 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.