Periodic Mesoporous Organosilica with Molecular-Scale Ordering Self-Assembled by Hydrogen Bonds

Nanoporous materials with functional frameworks have attracted attention because of their potential for various applications. Silica-based mesoporous materials generally consist of amorphous frameworks, whereas a molecular-scale lamellar ordering within the pore wall has been found for periodic mesoporous organosilicas (PMOs) prepared from bridged organosilane precursors. Formation of a crystal-like framework has been expected to significantly change the physical and chemical properties of PMOs. However, until now, there has been no report on other crystal-like arrangements. Here, we report a new molecular-scale ordering induced for a PMO. Our strategy is to form pore walls from precursors exhibiting directional H-bonding interaction. We demonstrate that the H-bonded organosilica columns are hexagonally packed within the pore walls. We also show that the H-bonded pore walls can stably accommodate H-bonding guest molecules, which represents a new method of modifying the PMO framework.