An alkylperoxo complex of Mn(II) bearing a highly hindered alkyl-substituted tris(pyrazolyl)borate ligand, TpBu t ,Pr i MnII(OOCMe2Ph) (TpBu t ,Pr i = hydrotris(3-tert-butyl-5-iso-propylpyrazolyl)borate), has been synthesized by dehydrative condensation of a corresponding mononuclear Mn(II) hydroxo complex TpBu t ,Pr i MnII(OH), with cumyl hydroperoxide. X-ray crystallography shows that the divalent manganese center of the alkylperoxo complex adopts an essentially tetrahedral geometry with a N3O ligand donor set.

The present study investigated the effects of Co addition on the surface structure and activity of Mo/Al2O3 for the hydrogenation of C6-C10 olefins. CoMo/Al2O3 (Co/Mo atomic ratio: 0.56) had lower activity for the hydrogenation of 1-hexene, 1-octene and 1-decene than Mo/Al2O3, whereas CoMo/Al2O3 had higher activity for the hydrogenation of 2-octene, 2,4,4-trimethyl-2-pentene and cyclohexene. Co/Al2O3 showed no activity for the hydrogenation of 1-octene and 2,4,4-trimethyl-2-pentene. NO uptake measurements over Mo/Al2O3 suggested that the coordinatively unsaturated sites of Mo atoms located at the edges of MoS2 clusters were active for the hydrogenation of both 1-octene and 2,4,4-trimethyl-2-pentene. Diffuse reflectance FTIR measurements of NO adsorbed on CoMo/Al2O3 (Co/Mo atomic ratio: 0.56) indicated that Co atoms blocked Mo atoms located at the edges of MoS2 clusters almost completely, i.e. formation of the Co _ Mo _ S structure. Therefore, formation of the Co _ Mo _ S structure depressed the activity for hydrogenation of 1-octene. The addition of Co promoter also increased the stacking number of MoS2 clusters. Presumably the increase in the stacking number of MoS2 clusters facilitated the adsorption of bulky olefins and promoted the hydrogenation. This may be the main reason for the promoting effect of Co for the hydrogenation of 2,4,4-trimethyl-2-pentene.

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