Dithiocarbamate copper(I) and silver(I) complexes: Synthesis, structure and thermal behavior

Abstract

Complexes [M(PBu3)n(S2CNRR′)] (M=Cu, Ag; n=1, 2, 3; R=R′=CH2CHCH2, (CH2)4, C2H4OH; R=Me, R′=C2H4OH; R=Bu, R′=C2H4OH) (4–9) are accessible by the reaction of [Cu(PBu3)nCl] (1a–c) or [Ag(PBu3)n(NO3)] (2a–c) with [K(S2CNRR′)] (3a–e). The respective silver(I) dithiocarbamates 7–9 and [Ag(PPh3)2(S2CNRR′)] (12a, R=Me; 12b, R=Bu) could be synthesized by the subsequent treatment of 3 with [AgNO3] (10) giving [AgS2CNRR′] (11) followed by addition of n equivalents of the phosphine L (L=PBu3, PPh3). Exemplary, the 31P{1H} NMR spectra of [Ag(PBu3)n(S2CNMe(C2H4OH)] (n=1.0, 1.5, 2.0, 2.5, 3.0, 3.5, 4.0, 4.5) were investigated in the temperature range of 308–178K showing phosphine ligand exchange processes in solution. The molecular structures of 12a,b in the solid state are reported confirming the monomeric architecture with coordination number 4 at silver, which is setup by a chelate-bonded (κ2-S,S′) S2CNR(C2H4OH) unit and two coordinated PPh3 ligands. The thermal behavior of selected samples was studied by thermogravimetry. Depending on R, R′ and the number of phosphines n, decomposition occurs in varying temperature ranges giving different decomposition residues (CuxS, x=1.96, 2; Ag, Ag2S), which were characterized by XRPD.