A catalyst surface with an active metal site, a shape-selective reaction space, and an NH 2 binding site for o-fluorobenzophenone was designed and prepared by the molecular imprinting of a supported metal complex on a SiO 2 surface. A ligand of a SiO 2-supported Ru complex that has a similar shape to the product of o-fluorobenzophenone hydrogenation was used as a template. An NH 2 binding site for o-fluorobenzophenone was spatially arranged on the wall of a molecularly imprinted cavity with a similar shape to the template. The structures of the SiO 2-supported and molecularly imprinted Ru catalysts were characterized in a step-by-step manner by means of solid-state magic angle spinning (MAS) NMR, XPS, UV/Vis, N 2 adsorption, XRF, and Ru K-edge EXAFS. The molecularly imprinted Ru catalyst exhibited excellent shape selectivity for the transfer hydrogenation of benzophenone derivatives. It was found that the NH 2 binding site on the wall of the molecularly imprinted cavity enhanced the adsorption of o-fluorobenzophenone, of which the reduction product was imprinted, whereas there was no positive effect in the case of o-methylbenzophenone, which cannot interact with the NH 2 binding site through hydrogen bonding. Tailoring a pocket: A molecularly imprinted Ru-complex catalyst with an NH 2 binding site for o-fluorobenzophenone has been successfully designed and prepared on a SiO 2 surface for shape-selective transfer hydrogenation (see scheme).
- molecular recognition
- supported catalysts