Steric effects are responsible for the bending in [(Pt(Me(2)phen)(mu -OH)}(2)](2+) (Me(2)phen = 2,9-dimethyl-1,10-phenanthroline). The large hinge angle is not expected on the basis of electronic effects alone, since hydroxo bridges and terminal nitrogen donors should lead to planar structures. Unexpected is the markedly increased stability against bridge-cleavage reactions, which could be relevant for the mechanism of reactions catalyzed by Pt-II and Pd-II complexes in aqueous medium. A structural study on the bridge-cleavage product [Pt-(Me(2)phen)(thiourea)(2)](2+) reveals strong distortions.