Synthesis, structure and reactivities of novel sigma-ruthenocenylplatinum complexes

Novel sigma-ruthenocenylplatinum complexes (3) and (4) have been synthesize d by the reaction of trimethylstannylruthenocene (1) or 1,1'-bis(trimethyls tannyl)ruthenocene (2) with Pt(cod)Cl-2, and characterized by means of spec tral analyses as well we an X-ray diffraction study. In the cyclic voltammo gram of complexes 3 and 4, irreversible two successive one-electron oxidati on peaks of the ruthenocenyl group appear at lower potential than that of i rreversible single-step two electron oxidation of ruthenocene. The treatmen ts 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 acetyl enedicarboxylate 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 compl exes 5 and 6 with CO, isocyanide or acetylene suggest that the reactivity o f 5 towards these substrates is not as high as that of 6. (C) 1999 Elsevier Science S.A. All rights reserved.