Different coordination behavior of a catechol phosphine and its sulfide: Formation of an unprecedented dinuclear rhodium complex with a non-coordinated PS unit

► A ditopic ligand with phosphine sulfide and catechol donor sites was synthesized. ► Low phosphine sulfide donor power impedes coordination of two ligands to one metal. ► Ligand backbone reduces tendency to form PS,O-chelate complexes. ► The P,S moiety remains inactive while two Rh atoms bind to the catecholate unit.