Ethenylene-bridged periodic mesoporous organosilicas : from E to Z

A novel class of periodic mesoporous organosilicas with E- and/or Z-configured ethenylene bridges was prepared under acidic conditions using the triblock copolymer Pluronic P123 as a structure directing agent. The isomeric configuration of the precursor has a drastic effect on the properties of the resulting PMO materials. The diastereoisomerically pure E-configured ethenylene bridged PMOs reveal higher structural ordering, narrower pore size distributions, and enhanced hydrothermal stability than their diastereoisomerically impure counterparts. These properties have been correlated with the molecular level structure of pore walls probed by solid-state NMR spectroscopy