Preparation and characterization of rhenium (I) tricarbonyl dithiocarbamate compounds; Re(CO)3(S2CNMe2)(L)

The title compounds were prepared in good yield by treatment of Re(CO)5Cl or [Re(CO)3(H2O)3]Br with sodium dimethyldithiocarbamate hydrate (NaS2CNMe2·H2O) and a neutral ligand yielding eight Re(CO)3(S2CNMe2)(L) derivatives: L = NH31, pyridine (py) 2, imidazole (im) 3, pyrazole (pz) 4, triphenylphospine (PPh3) 5, 1,3,5-triaza-7-phosphaadamantane (PTA) 6, t-butyl isocyanide (t-BuNC) 7, and cyclohexyl isocyanide (CyNC) 8. The resulting new complexes were characterized by 1H and 13C NMR and infrared spectroscopy. Each was also structurally elucidated by X-ray crystallography. General structural features in all eight compounds were similar. The orientation of the three single-faced ligands, py, im and pz, demonstrates an interaction with the filled π orbital of the dithiocarbamate. Compounds were tested for stability under conditions that mimic physiological conditions; 1–4 quickly decomposed, 7 and 8 decomposed over 24 h while 5 and 6 were stable.