Organic Group Functionalized Mesoporous Silicates

A. Walcarius and C. Delacote, Rate of Access to the Binding Sites in Organically Modified Silicates. 3. Effect of Structure and Density of Functional Groups in Mesoporous Solids Obtained by the Co-Condensation Route, Chem. Mater., 2003, 15, 4181. 

Many of the non-silica compositions showed problems with the stability and quality of the structure. Efforts to address these issues have been on going and quite successful in some cases such as all-alumina compositions (see below). Silica-based materials remain dominant as the most versatile and best quality molecular sieves (structure and stability) available by a facile synthesis. These attributes, especially the convenient synthesis made mesoporous silicate attractive for post-synthesis functionalization with other elements as well as organic moieties with active groups/ccnters. Recently the compositional diversity has been extended further to include both silica and organic moieties within the framework. The new class is referred to as periodic mesoporous organosilicas (PMOs). The synthesis involves surfactant-assisted assembly by hydrolysis of organo-silicon compounds. Additional discussion of the PMOs is presented below. 

Walcarius, A. and Delacote, C. (2003) Rate of access to the binding sites in organically modified silicates 3. Effect of structure and density of functional groups in mesoporous solids obtained by... 

Another approach for the functionalization of mesoporous material is the PMO. It is a special type of mesoporous organosilica with integrating organic groups (R) such as (R 0)3-Si-R-Si-(0R)j (R = methane, ethane, ethylene, acetylene, tris[3-(trimethoxysilyljpropyljisocyanurate, porphyrin, and so on) inside the siliceous walls. 

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