The chemistry of hybrid materials obtained from organic-bridged silane precursors is very successful in opening new routes for synthesis of hybrid mesoporous materials. Several reports are available on -CH 2 -, -CH 2 -CH 2 -, -CHdCH-, -C 6 H 4 -, and thiophene-bridged mesoporous polysilsesquioxanes of different morphologies. [1][2][3] Remarkable advances have already been achieved in the fabrication of templated sol-gel materials (so-called hybrid mesoporous polysilsesquioxanes) with desirable morphology. This includes thin films, particulate materials, and patterns printed on solid substrates by employing pen lithography and ink-jet printing. 4 However, the amorphous pore walls of these materials could hinder their utility for various potential applications. Recently, we reported the surfactant-mediated synthesis of benzene-silica hybrid materials with precise control of the nanoarchitecture possessing well-oriented building blocks of organic and inorganic fragments. 5 The material showed the hexagonal array of mesopores and crystal-like pore walls exhibiting structural periodicity in the wall along the channel direction with a spacing of 7.6 Å. The sulfonated derivatives of mesoporous phenylene-bridged silsesquioxane can be use as solid acid catalysts in several liquid and gas-phase reactions as well as solid electrolytes for fuel cells. 5,6 It will be interesting to see whether this unique rearrangement in the wall can be generalized for hybrid materials made of other combinations of organic and inorganic units. The work by Shea et al. describes the detailed synthesis of biphenyl containing organic-inorganic silica gel polymers by hydrolysis and polycondensation of organosilane precursors. 7 However, the gels were frequently considered as amorphous material with no preferential orientation of the molecular units (isotropic orientation), but the materials have considerably high surface areas. Later, the controlled anisotropic organization of nanostructured biphenylsilica hybrid materials using 4,4′bis(trimethoxysilyl)biphenyl precursor was demonstrated by its bifringence properties. 8,9 Here we report the successful synthesis of an ordered mesoporous biphenylene-bridged silsesquioxane with crystal-like pore wall similar to those recently reported for phenylene-bridged silsesquioxane.The synthesis of mesoporous biphenylene-bridged polysilsesquioxane was accomplished using 4,4′bis(triethoxysilyl)biphenyl [(C 2 H 5 O) 3 Si-(C 6 H 4 ) 2 -Si(OC 2 H 5 ) 3 ] precursor in the basic medium in the presence of octadecyltrimethylammonium chloride (C 18 -TMACl) surfactant. To obtain a highly ordered material it is important to control both the reaction conditions and the initial reactant ratio. In a typical procedure, the 4,4′bis(triethoxysilyl)-biphenyl (2.5 mmol) was added to a mixture of C 18 TMACl surfactant (3.2 mmol), 6 N sodium hydroxide (30.4 mmol), and distilled water (3.3 mol) under vigorous stirring at ambient temperature. The suspension was stirred for another 20 h. Heating the suspension at ∼95°C for 22 h un...

Novel sulfuric acid-functionalized mesoporous benzene-silicas with a molecular-scale periodicity in the walls were derived from the mesoporous benzene-silica possessing mercaptopropyl groups by the oxidative transformation of -SH into -SO3H.

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Amination of phenylene moieties in crystal-like mesoporous silica hybridized with phenylene is successfully achieved with close to 28% conversion of phenylene by a two-step chemical transformation process while preserving both the ordered mesostructure and crystal-like molecular scale periodicity of the parent material.

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We report that 2,6-naphthylene-bridged periodic mesoporous organosilicas exhibit unique fluorescence behavior that reflects molecular-scale periodicities in the framework. Periodic mesoporous organosilicas consisting of naphthalene-silica hybrid frameworks were synthesized by hydrolysis and condensation of a naphthalene-derived organosilane precursor in the presence of a template surfactant. The morphologies and meso- and molecular-scale periodicities of the organosilica materials strongly depend on the synthetic conditions. The naphthalene moieties embedded within the molecularly ordered framework exhibited a monomer-band emission, whereas those embedded within the amorphous framework showed a broad emission attributed to an excimer band. These results suggest that the naphthalene moieties fixed within the crystal-like framework are isolated in spite of their densely packed structure, different from conventional organosilica frameworks in which only excimer emission was observed for both the crystal-like and amorphous frameworks at room temperature. This key finding suggests a potential to control interactions between organic groups and thus the optical properties of inorganic/organic hybrids.