Synthesis and structures of monomeric [chloro(isatin-3-thiosemicarbazone)bis(triphenylphosphine)]copper(I) and dimeric [dichlorobis(thiophene-2-carbaldehyde thiosemicarbazone)bis(triphenylphosphine)]dicopper(I)] complexes

Reaction of copper(1) chloride with thiophene-2-carbaldehyde thiosemicarbazone (Httsc) in acetonitrile in the presence of Ph3P yielded a sulfur-bridged dimer [CU2Cl2(mu(2)-S-HttSC)(2)(PPh3)(2)].2CH(3)CN (1), while a similar reaction with isatin-3-thiosemicarbazone (H(2)itsc) formed a monomer, [CuCI(H(2)itsc)(Ph3P)(2)].2CH(3)CN (3). Furan-2-carbaldehyde thiosemicarbazone (Hftsc) also formed a compound of the composition [CU2Cl2(HftSC)(2)(PPh3)(2)] (.) 2H(2)O (2). Complexes 1-3 have been characterized using elemental analysis, IR, H-1 and P-31 NMR spectroscopy and single crystal X-ray crystallography (I and 3). Acetonitrile is engaged in hydrogen bonding with the chlorine atom {NCCH2-H...Cl)}, which is necessary for the stabilization of the bridging sulfur in 1. In compound 3, however, acetonitrile is strongly hydrogen bonded to the NH hydrogen of the isatin ring {CH3CN...NH(isatin)} and not to the chlorine atom. The Cu...Cu contact of 2.7719(5) angstrom in dimer 1 is close to twice the van der Waals radius of the Cu atom (2.80 angstrom). (C) 2007 Elsevier Ltd. All rights reserved.