Synthesis, structure and reactivities of novel σ-ruthenocenylplatinum complexes

Novel sigma-ruthenocenylplatinum complexes (3) and (4) have been synthesized by the reaction of trimethylstannylruthenocene (1) or 1,1'-bis(trimethylstannyl)ruthenocene (2) with Pt(cod)Cl-2, and characterized by means of spectral analyses as well we an X-ray diffraction study. In the cyclic voltammogram of complexes 3 and 4, irreversible two successive one-electron oxidation peaks of the ruthenocenyl group appear at lower potential than that of irreversible single-step two electron oxidation of ruthenocene. The treatments of sigma-ruthenocenylplatinum complex (5) with carbon monoxide and aryl isocyanides cause the insertion into Pt-C bond to give insertion products (7) and (9), respectively. The reaction of 5 with dimethyl or diethyl acetylenedicarboxylate results in the formal insertion of acetylene into the C-H bond of the cyclopentadienyl group at 2-position to give 11 as observed in the reaction of sigma-ferrocenyl analog (6). Competitive reactions of complexes 5 and 6 with CO, isocyanide or acetylene suggest that the reactivity of 5 towards these substrates is not as high as that of 6. (C) 1999 Elsevier Science S.A. All rights reserved.