Technetium(V) Complexes of Substituted Benzimidazolylalcohols and Thiols. Influence of the Donor Atom Type on the Configuration

Cationic square-pyramidal complexes of general formula (TcO(L)+ 2]Cl− were prepared by the reaction of (n-Bu4N)TcOCl4 with the potentially bidentate N,S-donor benzimidazolylthiols (HL) as ligands in the presence of triethylamine. The corresponding reaction with the N,O-donor benzimidazolylalcohols led to the formation and isolation of the neutral six-coordinate complexes TcOCl(L)2. These compounds were characterized by elementalanalysis, vibrational and optical spectroscopy. Mechanisms for the formation reactions and probable configurations of the complexes are proposed on the basis of qualitative studies and spectroscopic results.