Preparation and catalytic activity of periodic mesoporous organosilica incorporating Lewis acidic chloroindate(III) ionic liquid moieties

Preparation of novel periodic mesoporous organosilica (PMO) materials of SBA-15 incorporating Lewis acidic chloroindate(III) ionic liquid moieties was achieved via a multistep process, in which N-(3-triethoxysilylpropyl), N(3)-(3-trimethoxysilylpropyl-4,5-dihydroimidazolium chloride was firstly synthesized and used as bridging organosilica precursor to co-condense with tetraethoxysilane (TEOS) in the presence of P123, followed by removal of the template, then the addition of InCl3 gave rise to the PMO materials with Lewis acidity. The obtained PMO materials were well characterized. The XRD, TEM, and N2 adsorption–desorption results indicated that the PMO materials retained the structural integrity during the template extraction and successive InCl3-loading process. FT-IR and solid-state 29Si and 13C CP/MAS-NMR analyses showed the organic structure of the bridging organosilica precursor could be incorporated into the PMO materials invariantly. Compared with SBA-15 supported InCl3, the PMO materials revealed high efficiency and better reusability in the Friedel–Crafts reaction between benzene and benzyl chloride. More importantly, such immobilized chloroindate(III) ionic liquids had low moisture sensitivity, showing the great potential for practical applications.