Osmium (III) halide complexes with para- and meta- substituted benzeneseleninato ligands

The preparation and magnetic susceptibility, electronic, infrared, electrical conductivity and thermogravimetric studies of a series of monomethylsubstituted piperidine dithiocarbamates of silver(I), gold(I) and gold(III) are reported. The complexes are formulated as AgRdtc, AuRdtc, Au(Rdtc)3. Au(Rdtc)2X and AuRdtcX2 (X=Cl, Br). The dithioligands exhibit both bidentate behaviour acting as S,S ' -donors and monodentate behaviour acting as S-donors, depending on the type of the complex. The diamagnetic behaviour of the gold(III) derivatives is in accord with the usual low-spin d8 configuration. The metal-sulphur and metal-halide stretches have also been assigned and are in accord with the proposed structures. The molecular weight determinations indicate monomeric structures for the Au(Rdtc)3 and AuRdtcX2 complexes and dimeric structures for the Au(Rdtc)2X derivatives. The results of the spectroscopic studies indicate that in the Au(Rdtc)3 complexes one of the dithiocarbamate groups must act as a bidentate ligand, while the other two act as monodentates giving square planar structures.