Oxotechnetium(V) Complexes with a Novel Class of Tridentate Thiosemicarbazide Ligands

Abstract

A novel tridentate thiosemicarbazide-type ligand class with an SNS donor set, H₂L¹, was prepared by reactions of N-[N′,N′-dialkylamino(thiocarbonyl)]benzimidoyl chlorides with thiosemicarbazides. H₂L¹ ligands readily react with (NBu₄)[TcOCl₄] in MeOH under the formation of red oxotechnetium(V) complexes of composition [TcOCl(L¹)]. The monomeric, five-coordinate compounds are air-stable and bind (L¹)²⁻ tridentate in the equatorial coordination sphere. The compounds represent the first examples of oxotechnetium(V) complexes with NS chelate-bonded thiosemicarbazones.