A novel approach to acrylate/methacrylate‐based monolithic systems via electron‐beam (EB) initiated polymerization is described. The thus obtained monolithic columns were found suitable for the analytical scale separation of proteins. The novel concept of monolith synthesis was successfully extended to the synthesis of large diameter (20 mm × 300 mm id) monolithic columns applying EB irradiation in a pulsed mode. A homogeneous structure in terms of particle size and porous structure was again realized throughout the entire monolith. Functionalization of the monolithic columns was accomplished via copolymerization of a functional monomer, N,N‐dipyrid‐2‐ylmethacryl amide. The thus obtained functional monoliths were loaded with Pd (II) and used for the Heck‐coupling of styrene with iodobenzene in a continuous process.

The synthesis of ring-opening metathesis polymerization (ROMP) derived monolithic media prepared from cis-cyclooctene (COE) as monomer, tris(cyclooct-4-ene-1-yloxy)methylsilane (CL) as cross-linker, toluene as microporogen, and 2-propanol as macroporogen is described. Monolithic supports with varying composition in terms of COE, CL, microporogen, and macroporogen were prepared using RuCl2(Py)2(1,3-Mes2-imidazolin-2-ylidene)(CHC6H5) (Mes = 2,4,5-trimethylphenyl, Py = pyridine) and pyridine as modulator and characterized via inverse size exclusion chromatography (ISEC) and electron microscopy. Monoliths 3 × 100 mm in size were used for the separation of a mixture of five proteins, i.e., ribonuclease A, lysozyme, insulin, cytochrome c, and myoglobin. Semipreparative separation of these compounds was achieved within less than 150 s by applying gradient elution. Peak half-widths (ω0.5) were <6 s, and resolution (R s) was >1.2 throughout. Functionalization of the novel support was accomplished in situ and exemplified by grafting various amounts of 7-oxanorborn-5-ene-2,3-dicarboxylic anhydride on the monolithic structure. By this approach, carboxylic acid loadings up to 86 μmol/g, corresponding to 0.71 wt %, were realized.

Porous polymeric monoliths were prepared via electron beam triggered free radical polymerization of (meth)acrylates. Post‐synthesis functionalization of these supports was accomplished via electron beam initiated free radical graft polymerization of methacryloyl‐substituted NHC precursors. The grafted precursors were converted into the corresponding copper complexes. Cu‐loadings were between 1.3 mg · g−1 and 1.5 mg · g−1. These supported catalysts were used in selected CO hydrosilylation and cyanosilylation reactions using a continuous flow setup.magnified image

Monolithic materials were prepared via electron‐beam curing from ethyl methacrylate, trimethylolpropane triacrylate, and norborn‐5‐ene‐2‐ylmethyl acrylate. Reaction of the norborn‐2‐ene groups with either RuCl2(PCy3)2(CHPh) (1) or RuCl2(PCy3)(1,3‐dimesityl‐4,5‐dihydroimidazol‐2‐inylidene)(CHPh) (2) resulted in the surface attachment of the initiators. The extent of initiator immobilization was found to be substantially higher for 1 than for 2. Reaction of the surface immobilized initiators with various monomers resulted in the desired surface modification of EB‐derived monoliths. The amounts of grafted monomer were determined by elemental analysis and ICP‐OES.magnified image