Synthesis, bifunctionalization, and application of isocyanurate-based periodic mesoporous organosilicas

Isocyanurate-containing silsesquioxane-bridged periodic mesoporous organosilicas (ICS-PMOs) were synthesized by self-assembly of the nonionic surfactant P123, EO₂₀PO₇₀EO₂₀, and trimethoxysilyl-functionalized isocyanurate (ICS-Si) under acidic conditions in the presence of inorganic additives. The ICS-PMOs have been modified by an alkyl-bridged organosilane (i.e., Et-Si; Et = -CH₂CH₂-) by substituting ICS-Si with Et-Si in the precursors, at various molar ratios, resulting in bifunctionalized PMOs exhibiting two types of bridged groups (ICS-Et-PMOs). The obtained bifunctionalized ICS-Et-PMOs have been characterized by X-ray diffraction, transmission electron microscopy, nitrogen physical sorption, and solid-state ²⁹Si and ¹³C magic angle spinning NMR spectroscopy. Experiments show that the ICS-Et-PMOs exhibit hexagonal mesoscopic structures. Increasing the content of the Et-Si functionality in the precursors is found to significantly improve the mesostructural ordering of the product. It is suggested that fluoride anions as additives play an important role in the formation of wellordered ICS-PMOs and as well the bifunctionalized ICS-Et-PMOs in the presented experiments. The ICS-PMO materials were used to chemically adsorb H₂PtCl₆, and Pt nanoparticles were subsequently prepared within the mesopores of ICS-PMO by NaBH₄ reduction in solution, highlighting the simplicity in exploiting the application of such PMOs in nanomaterials fabrication.