A new class of supported carbonyl manganese catalyst was prepared by treating the dimeric decacarbonyldimanganese(0), Mn2(CO)10, with insoluble aminated poly(siloxane) surface. Solid state FT-IR spectra indicated that the supported catalyst is a dimeric complex that is substituted with two amine ligands, one at each Mn atom. The supported manganese complex was investigated as catalyst for the hydrosilylation reaction of terminal olefins. Contrary to the homogeneous Mn2(CO)10 catalytic system, the supported manganese complex was completely selective toward the hydrosilylation reaction with no detectable olefin isomerization or other side-reaction products. Furthermore, the catalyst was selective to produce the linear hydrosilylation product rather than the branched one. No lowering in catalyst activity due to the support was observed. A good proportion of the catalyst activity after separation and reuse was retained for at least four times. Highly reproducible catalytic activity measurements were obtained with catalytic samples taken from same prepared batch. Different prepared batches showed lower reproducibility. The effect of different reaction parameters, such as the solvent effect, the temperature effect, the concentration effect and the added-ligand effect have also been studied. Laine's kinetic studies indicated that the cluster remained intact during the reaction.
A new class of supported carbonyl manganese catalyst was prepared by treating the dimeric decacarbonyldimanganese(0), Mn2(CO)10, with insoluble aminated poly(siloxane) surface. Solid state FT-IR spectra indicated that the supported catalyst is a dimeric complex that is substituted with two amine ligands, one at each Mn atom. The supported manganese complex was investigated as catalyst for the hydrosilylation reaction of terminal olefins. Contrary to the homogeneous Mn2(CO)10 catalytic system, the supported manganese complex was completely selective toward the hydrosilylation reaction with no detectable olefin isomerization or other side-reaction products. Furthermore, the catalyst was selective to produce the linear hydrosilylation product rather than the branched one. No lowering in catalyst activity due to the support was observed. A good proportion of the catalyst activity after separation and reuse was retained for at least four times. Highly reproducible catalytic activity measurements were obtained with catalytic samples taken from same prepared batch. Different prepared batches showed lower reproducibility. The effect of different reaction parameters, such as the solvent effect, the temperature effect, the concentration effect and the added-ligand effect have also been studied. Laine's kinetic studies indicated that the cluster remained intact during the reaction.
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Decacarbonyldimanganese(O) complex, Mn2(CO)10, has been evaluated as a catalyst for hydrosilylation reactions of 1-hexene with tertiary silanes, Et3SiH and (EtO)3SiH. The reaction of Et3SiH appears to be first order with respect to the catalyst, to the hexene and to the silane, although catalyst deactivation occurs when relatively high silane concentrations are used. The reaction rate is slightly affected by varying the type of the silane used. The rate of disappearance of the tertiary silane is consistent with that of the 1-hexene, which means that the catalyst is selective to hydrosilylation reactions. This was confirmed by following the rates of disappearance of Si-H and C=C IR bands at 2210, 2100 and 1650 cm−1 for (EtO)3SiH, Et3SiH and 1-hexene respectively. A comparison of the behaviour of Mn2(CO)10 with that of Co2(CO)8 is reported here, together with a suggested mechanism for the manganese catalyst.
A new class of supported carbonyl manganese catalyst was prepared by treating the dimeric decacarbonyldimanganese(0), Mn2(CO)10, with insoluble aminated poly(siloxane) surface. Solid state FT-IR spectra indicated that the supported catalyst is a dimeric complex that is substituted with two amine ligands, one at each Mn atom. The supported manganese complex was investigated as catalyst for the hydrosilylation reaction of terminal olefins. Contrary to the homogeneous Mn2(CO)10 catalytic system, the supported manganese complex was completely selective toward the hydrosilylation reaction with no detectable olefin isomerization or other side-reaction products. Furthermore, the catalyst was selective to produce the linear hydrosilylation product rather than the branched one. No lowering in catalyst activity due to the support was observed. A good proportion of the catalyst activity after separation and reuse was retained for at least four times. Highly reproducible catalytic activity measurements were obtained with catalytic samples taken from same prepared batch. Different prepared batches showed lower reproducibility. The effect of different reaction parameters, such as the solvent effect, the temperature effect, the concentration effect and the added-ligand effect have also been studied. Laine's kinetic studies indicated that the cluster remained intact during the reaction.