Preparation and reactions of the (pentamethylcyclopentadienyl)rhodium(III) complexes bearing 1,1'-bis(diphenylphosphinomethyl)ferrocene (dpmf) or 1,1'-bis(diphenylphosphino)ferrocene (dppf)

摘要

Reactions of [Cp~*RhCl_2]_2 with 1,1'-bis(diphenylphosphinomethyl)ferrocene (dpmf) or 1,1'-bis(diphenylphosphino)ferrocene (dppf) gave the bridged complex [Cp~*RnCl_2]_2(#mu#-diphos) (1: diphos = dpmf; 2: diphos = dppf). Reaction with dppf in the presence of NaPF_6 gave the cationic chelated [Cp~*RhCl(dppf-P,P')](PF_6) complex 3. Complex 1 reacted with xylyl isocyanide (XylNC) in the presence of NaPF_6 to yield [Cp_2~*Rh_2Cl_2(#mu#-dpmf)(XylNC)_2](PF_6)_2, 4, in low yield. [Cp~*Rh(dppf-P,P')(MeCN)](PF_6)_2, 5a, was prepared from 3, NaPF_6 and AgNO_3 in MeCN. The acetonitrile ligand in this complex was replaced readily with Lewis bases (L), such as CO and isocyanides, to form [Cp~*Rh(dppf-P,P')(L)](PF_6)_2, 5. Structures of 2, 3 and 5b (L = p-TosCH_2NC) were confirmed by X-ray analyses, in which their molecules have the piano stool structure.