Oxidorhenium(V) complexes with tetradentate thiourea derivatives

Article abstract of DOI:10.1016/j.poly.2012.06.016

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 (NBu ₄)[ReOCl₄] or [ReOCl₃(PPh₃) ₂] under formation of monoxido complexes of the composition [ReO{(H)L}(Y)] with various co-ligands (Y = ReO₄^-, F ₃CCO₂^-, 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.