Oxidorhenium(V) complexes with tetradentate thiourea derivatives

Abstract: Potentially tetradentate, binegative thiocarbamoylbenzamidines derived from o-phenylenediamines (H2L or H3L) are shown to be suitable ligand systems for oxidorhenium(V) cores. They readily react with (NBu4)[ReOCl4] or [ReOCl3(PPh3)2] under formation of monoxido complexes of the composition [ReO{(H)L}(Y)] with various co-ligands (Y=ReO4 −, F3CCO2 −, Cl− or methanol) or μ-oxido dimers depending on the reaction conditions applied. Representative products were isolated and studied spectroscopically and by X-ray diffraction. Substitutions in the periphery of the ligands allow the introduction of a carboxylic substituent, which may serve as anchor group for future bioconjugation of appropriate rhenium (or technetium) complexes. [Copyright &y& Elsevier]