Cyclodextrin-based porous silica materials as in situ chemical "nanoreactors" for the preparation of variable metal-silica hybrids

Inclusion complexes of cyclodextrins with organometallic coordination compo unds of Pd, Pt, Rh, Fe, Ni, and Ru have been used to produce porous metal-s ilica hybrid materials. The cyclodextrins are templates for the structure o f the silica and lead to a uniform "wormtype" pore system. After the templa ting step the organometallic compounds can be employed as in situ precursor s for the preparation of metal nanoparticles within the pore system, thus l eading to a one-step synthesis of silica-supported metal catalysts. These n ew materials are characterized and how the chemical confinement of the sili ca pores can influence the size, structure, and distribution of the nanopar ticles is studied.