Monomeric/dimeric complexes of fac-[Re(CO)3]+ with benzoylthiourea derivatives

The reactions of [Re(CO)5Br] with the potentially bidentate ligands N,N-dialkylbenzoylthiourea (HL1) and its N,N-diphenyl derivative (HL2) were studied. In the complex fac-[Re(CO)3(HL1)2Br] (1) the two neutral HL1 ligands are coordinated in a monodentate manner via the thiourea sulfur atom. Coordination of the monoanionic chelate L2 occurs through the neutral benzoyl oxygen atom and the anionic sulfur atom, which also acts as a bridge to the second metal centre, in the dimeric complex [Re2(CO)6(L2)2] (2). The crystal structures of 1 and 2 were determined by X-ray single crystal diffraction. UV–vis absorption spectra of the complexes show the intraligand and MLCT transitions.