| Abstract
| - Inorganic−organic hybrid mesoporous materials were prepared by cocrystallization of a “sandwich”type polyoxometalate, [ZnWZn2(H2O)2(ZnW9O34)2]12-, and branched tripodal organic polyammonium salts,tris[2-(trimethylammonium)ethyl]-1,3,5-benzenetricarboxylate or 1,3,5-tris[4-(N,N,N-trimethylammoniumethylcarboxyl)phenyl]benzene trications. Scanning electron microscopy (SEM) and transmission electronmicroscopy (TEM) showed formation of three-dimensional perforated coral-shaped amorphous materialswith the organic cations surrounding polyoxometalate anions. N2 sorption analysis showed that the hybridmaterials have a BET surface area of ∼30−50 m2 g-1 and an average pore diameter of 36 Å leading to theclassification of these materials as mesoporous materials with moderate surface areas. These hybridmaterials behaved as very effective and selective heterogeneous catalysts for the epoxidation of allylicalcohols and oxidation of secondary alcohols to ketones with hydrogen peroxide as oxidant. The activityand selectivity of the heterogeneous catalysts based on the hybrid materials was similar to those ofhomogeneous catalysts based on the same [ZnWZn2(H2O)2(ZnW9O34)2]12- polyoxometalate.
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