A n ultralarge pore titanium silicate with MCM-41 structure has been prepared by direct hydrothermal synthesis; this material gives rise t o useful catalysts for the selective oxidation of small and large organic compounds.

Ti/MCM-41 is a well-known heterogeneous catalyst for alkene epoxidation with organic peroxides. This titanosilicate contains isolated titanium atoms forming part of a framework of mesoporous silica whose structure is formed by parallel hexagonal channels 3.2 nm in diameter. The surface area and porosity of Ti/MCM-41 are about 880 m(2) g(-1) and 0.70 cm(3) g(-1), respectively. These values are among the highest for any material. Herein, we show that Ti/MCM-41 exhibits photovoltaic activity. Dye-sensitized solar cells using mesoporous Ti/MCM-41 (2.8-5.7 % Ti content) as active layer, black dye N3 as photosensitizer and I(3) (-)/I(-) in methoxyacetonitrile as electrolyte exhibit a V(OC), J(SC) and FF of 0.44 V, 0.045 mA cm(-2) and 0.33, respectively. These values compare well against 0.75 V, 4.1 mA cm(-2) and 0.64, respectively, measured for analogous solar cells using conventional P-25 TiO(2). However, the specific current density (J(SC)/Ti atom) for the Ti/MCM-41 is very similar to that of P25 TiO(2).

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Mesoporous Aluminosilicate MCM-41 as a Convenient Acid Catalyst for Friedel-Crafts Alkylation of a Bulky Aromatic Compounds with Cinnamyl Alcohol.-The mesoporous aluminosilicate MCM-41 is found to be an efficient catalyst for the Friedel-Crafts reaction of the phenol (I) with the cinnamyl alcohol (II) to give the benzopyrans (III) and (V). This catalyst is superior to other aluminosilicates with different pore size distribution. -(ARMENGOL, E.; CANO, M. L.; CORMA, A.; GARCIA, H.; NAVARRO, M. T.; J.