Periodic Mesoporous Organosilica with Large Cagelike Pores

Abstract

After the recent discovery of periodic mesoporous organosilicas (PMOs), 1-4 their synthesis, reactivity, structural characterization, and prospective applications have received much attention. [5][6][7][8][9][10][11][12][13][14] PMOs were already found to be promising as catalysts, 11 templates for nanostructure synthesis, 12 and selective adsorbents. 14 There is currently a quest for expanding the pore size domain attainable for PMOs 15-18 because large-pore PMOs are of kin interest from the point of view of immobilization and encapsulation of large molecules. 17,18 Standard PMO synthesis using alkylammonium surfactants affords pore diameters below about 5 nm, [1][2][3][4] and pore diameters of PMOs templated by neutral amines 19 and oligomeric surfactants 9,[19][20][21][22] were also found to be below this limit. 9,19 So the only large-pore

Highly Ordered Mesoporous Organosilica Hybrid Materials

“…12 nm, were obtained. 35 The structure was similar to that of FDU-1 silica 36 derived using TEOS under similar synthetic conditions. Guo et al found that the addition of a salt such as NaCl improves the degree of ordering of the materials.…”

Advances in Microporous and Mesoporous Solids—Highlights of Recent Progress

“…Due to strong hydrophobic interactions between the organosilicate precursors and hydrophobic chains in block copolymer templates, pore sizes of PMOs tend to be smaller than those of pure silicate structures obtained with the same template. [42] Ozin and co-workers demonstrated that increased pore sizes in PMOs derived from bis(triethoxysilyl)ethane can be achieved by using acidic conditions and replacing PEO± PPO±PEO triblock copolymer templates with a PEO±poly (butylene oxide)±PEO triblock copolymer. [42] The resulting structure was tentatively assigned as a cubic structure with cage-like pores as large as 10 nm.…”

“…[42] Ozin and co-workers demonstrated that increased pore sizes in PMOs derived from bis(triethoxysilyl)ethane can be achieved by using acidic conditions and replacing PEO± PPO±PEO triblock copolymer templates with a PEO±poly (butylene oxide)±PEO triblock copolymer. [42] The resulting structure was tentatively assigned as a cubic structure with cage-like pores as large as 10 nm. With phenylene bridges, pores between 6.0 and 7.4 nm could be obtained under acidic conditions using PEO±PPO±PEO triblock copolymers.…”

Periodic mesoporous organosilica incorporating a catalytically active vanadyl Schiff base complex in the framework

“…More recently, a new family of periodic mesoporous organosilicas (PMOs) in which the organic compound is forming part of the silica framework rather than occupying the channel space has been reported [17][18][19][20][21][22][23][24][25]. The crucial issue for the preparation of PMOs is the synthesis of a convenient organic precursor that must contain two terminal alkoxy silane groups.…”