Technetium(I) Carbonyl Dithiocarbamates and Xanthates

Technetium(I) tetracarbonyl complexes with diethyldithiocarbamate and methylxanthate ligands [TcL(CO)4] (L = S2CNEt2 and S2COMe) were prepared. Conditions required for the formation of these complexes were found. The crystal and molecular structure of the xanthate complex was determined by single-crystal X-ray diffraction. [Tc(S2CNEt2)(CO)4] undergoes decarbonylation both in solution and in the course of vacuum sublimation with the formation of a dimer [Tc(S2CNEt2)(CO)3]2 whose structure was determined by single-crystal X-ray diffraction. In donor solvents, [Tc(S2CNEt2)(CO)4] and [Tc(S2COMe)(CO)4] undergo decarbonylation with the formation of tricarbonyl solvates [TcL(CO)3(Sol)]. The crystal structure of the pyridine solvate [Tc(S2CNEt2)(CO)3(py)], chosen as an example, was determined by single-crystal X-ray diffraction. The possibility of using bidentate S-donor acidic ligands for tethering the tetracarbonyltechnetium fragment to biomolecules was examined.