Non‐porous polyurethane‐based monoliths are prepared under solvent‐induced phase separation conditions. They possess low specific surface areas of 0.15 m2 g−1, pore volumes of 1 µL g−1, and a non‐permanent, solvent‐induced microporosity with pore dimensions ≤1 nm. Mesoporosity can be introduced by varying the monomers and solvents. A tuning of the average solubility parameter of the solvent mixture by increasing the macroporogen content results in a decrease in the volume fraction of micropores from 70% to 40% and an increase in the volume fraction of pores in the range of 1.7–9.6 nm from 22% to 41% with only minor changes in the volume fraction of larger mesopores in the range of 9.6–50 nm. The polymeric monoliths are functionalized with quaternary ammonium groups, which allowed for the immobilization of an ionic liquid that contained the ionic Rh‐catalyst [1‐(pyrid‐2‐yl)‐3‐mesityl)‐imidazol‐2‐ylidene))(η4‐1,5‐cyclooctadiene)Rh(I) tetrafluoroborate]. The supported catalyst is used in the hydrosilylation of 1‐alkynes with dimethylphenylsilane under continuous flow using methyl‐tert‐butyl ether as second liquid transport phase. E/Z‐selectivity in hydrosilylation is compared to the one of the analogous biphasic reactions. The strong increase in Z‐selectivity is attributed to a confinement effect provided by the small mesopores.
A hard‐templating method is presented for the synthesis of functional ring‐opening metathesis polymerization (ROMP) derived, poly(norborn‐2‐ene)‐based monolithic supports prepared under solvent‐induced phase separation conditions using the first‐generation Grubbs initiator RuCl2(PCy3)2(CHPh) (1, Cy = cyclohexyl). Norborn‐2‐ene (NBE), 1,4,4a,5,8,8a‐hexahydro‐1,4,5,8‐exo,endo‐dimethanonaphthalene (DMN‐H6) and trimethylolpropane‐tris‐(5‐norbornene‐2‐yl‐carboxylate (TMPTNC) are used as monomers and crosslinkers, respectively. 2‐Propanol and toluene are used as macro‐ and microporogen. Silica (SiO2) nanowires (SNWs) surface‐modified with NBE are used as hard templates. exo,endo‐Norborn‐5‐ene‐2‐ylmethanol (NBE‐CH2OH) is used as functional comonomer. The tailored porogenic system together with the surface‐functionalized SNWs allows for a full dispersion of the SNWs in the polymerization mixture and their incorporation into the monolithic structure during the phase separation process. This way, ROMP‐derived monoliths with pore dimensions of 10–15 nm, specific surface areas up to 3.7 m2 g−1, and pore porosities up to 33% are obtained after removal of the SNWs by chemical etching at room temperature.
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