Selective epoxidation of olefins catalyzed by oxodiperoxomolybdenum(VI) complexes immobilized over highly ordered 2D-hexagonal mesoporous silica

Two oxodiperoxomolybdenum(VI) complexes of 8-quinolinol have been immobilized over a highly ordered 2D-hexagonal mesoporous silica. The latter has been synthesized hydrothermally by using cationic-non-ionic mixed surfactant templating route. The mesoporous silica and the immobilized materials were thoroughly characterized by powder X-ray diffraction, N-2 sorption, transmission electron microscopy (TEM), UV-vis and Fr-IR spectroscopic tools and elemental analyses. Experimental results revealed 6.7-7.1 wt% loading of metal complexes on the mesoporous silica host. The immobilized nanostructured materials showed very good catalytic activity and excellent recycling efficiencies over their respective homogeneous catalysts for the epoxidation of different olefins in the presence of H2O2/NaHCO3 system. High catalytic efficiency could be attributed to the heterogenization of soluble metal complexes on the high surface area mesoporous host. (c) 2008 Elsevier B.V. All rights reserved.