Synthesis, Crystal Structures, and Oxidation States of MM′X-Type Platinum–Rhodium Dinuclear Complexes Having Amidate Bridging Ligands

Six novel Pt-Rh dinuclear complexes (1-6), [PtRh(PVM)(2)(NH3)(2)Cl-3](.)4H(2)O (1, PVNI = tBuCONH-), [PtRh(PVM)(2)(en)Cl-3](.)3H(2)O (2, en = ethylenediamine), [PtRh(PVM)(2)(NH2CH3)(2)Cl-3](.)3H(2)O (3), [PtRh(PVM)(2)(NH(2)tBu)(2)Cl-3](.)3H(2)O (4), [PtRh(TCM)(2)(NH3)(2)CI3] (5, TCM = Cl3CCONH-), and [PtRh(BZM)(2)(NH3)(2)Cl-3](.)H2O (6, BZM = PhCONH-), have been synthesized from Pt mononuclear complexes having nitrogen-coordinated amidate ligands with noncoordinated amidate oxygen atoms. X-ray analysis revealed that compounds 1 and 2 form zigzag one-dimensional chains in the form [-Pt-Rh-CI-](n). The oxidation states of the metal ions have been determined by X-ray photoelectron spectroscopy (XPS) and Pt-195 NMR spectroscopic analysis, and are Pt(+2, d8)(...) Rh(+3, d(6)). In comparison with the Pt-Rh distances found in the literature, it has become apparent that the Pt-Rh dinuclear complexes have a dative Pt(d(8))-> Rh(d(6)) bond, where the Pt d(z)(2) orbital is stabilized by the overlap with the d(z)(2) orbital of the Rh atom. (c) Wiley-VCH Verlag GmbH & Co. KGaA.