Periodic Mesoporous Organosilicas with a Bifunctional Conjugated Organic Unit and Crystal-like Pore Walls

Abstract

The synthesis of a 2D hexagonal highly ordered periodic mesoporous 1,4-divinylbenzene-bridged organosilica (PMO) with crystal-like pore walls is reported. Both functionalities are realized by utilization of one single precursor (1,4-bis-((E)-2-(triethoxysilyl)vinyl)benzene (BTEVB) which was synthesized via Pd-catalyzed double Heck coupling of 1,4-dibromobenzene with vinyltriethoxysilane. Solid state 29Si MAS NMR and FT-IR spectroscopy confirms that during the hydrothermal PMO synthesis and subsequent extraction procedure (i) no Si−C bond cleavage occurred and (ii) the organic bridge is preserved. The novel PMO material with a pore diameter of 2.6 nm, a molecular scale periodicity of 1.19 nm within the pore walls, and a specific surface area of SBET = 730 m2/g offer various opportunities for further chemical modification within the mesopores as shown by bromination reactions.