Synthesis and Catalytic Properties of Hybrid Mesoporous Materials Assembled from Polyhedral and Bridged Silsesquioxane Monomers

Abstract

A family of hybrid mesoporous materials with high temperature stability was obtained by the suitable covalent combination of two types of siloxane precursors. Specifically, cubic T₈ polyhedral oligomeric (POSS) and aryl bridged silsesquioxane monomers (1,4-bis(triethoxysilyl)benzene, BTEB) play the role of nanobuilders. An optimal molar ratio of the two precursors (5–25 mol % of total silicon content from the BTEB disilane) generated a homogenous, highly accessible, and well-defined mesoporous material with hexagonal symmetry and narrow pore-size distribution. Physicochemical, textural, and spectroscopic analysis corroborated the effective integration and preservation of the two different nanoprecursors, thereby confirming the framework of the mesoporous hybrid materials. A post-synthesis amination treatment allowed the effective incorporation of amino groups onto the aryl linkers, thereby obtaining a stable and recyclable basic catalyst for use in CC bond-formation processes.