Klaus Rose

Metal complexes in inorganic matrices: Pert III. Catalytic activity of Rh(CO)Cl(PR3)2 heterogenised by the SOL-GEL method1

Abstract The catalytic activity of Rh(CO)Cl(PPh2CH2CH2SiO3/22·xSiO2, (catalyst P), prepared by the polycondensation of Rh(CO)Cl[PPh2CH2CH2Si(OEt)3]2 (H) with tetraethoxysilane is compared with that of the homogeneous compound H and with catalyst S, prepared by attaching H to the surface of SiO2. In the hydrosilylation of 1-hexene with triphenylsilane, P and S exhibit similar catalytic activities. In the absence of an olefin, P is an effective catalyst for the formation of poly- and oligo-siloxanes from hydrosilanes. P also catalyses CO oxidation and the water-gas shift reaction. Qualitative trends between the catalytic activity of P and its physical properties are discussed.

Metal complexes in inorganic matrices, Part II. CO reactions of chloro(carbonyl)(phosphine)rhodium complexes in a silica gel matrix

SummaryMaterials obtained by polycondensation of [Rh(CO)ClL2] [L=PPh2CH2CH2Si(OEt)3] with tetraethoxysilane (TEOS) irreversibly take up CO to give monomeric or dimeric [cis-Rh(CO)2ClL]: (L=PPh2CH2CH2SiO3/2·xSiO2) (2). The polymeric metal complex (2) is also obtained by CO treatment of [Rh2(CO)2Cl2L2] (4) or by polycondensation ofin-situ prepared (monomeric or dimeric) [Rh(CO)2ClL] with TEOS. Unlike comparable complexes in solution,(2) is extremely stable in respect to CO loss, even at higher temperatures andin vacuo.