Combining the advantages of homogeneous and heterogeneous catalysis is still a problem that has not been satisfactorily solved. Chemistry in interphases offers a new approach for overcoming the difficulties, as is described in this article. Owing to the swellable or porous matrix, an interphase represents a state which in the most favorable case is similar to that of a solution. Moreover the proper choice of a mobile hybrid copolymer enables the control of the density and accessibility of the reactive centers, which results in a distinct improvement of the activity of the catalysts (two examples are shown schematically).

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The trimethoxysilyl-(T)-functionalized ruthenium(II) complex cis-Cl(H)Ru(CO)(P∼O) 3 [2(T 0 ) 3 ] (P∼O: Pcoordinated ether-phosphine) is sol-gel processed with tetraethoxysilane (TEOS, Q 0 ) and aluminum 2-propanolate [Al(OiPr) 3 ]. All components are simultaneously polycondensed to result in the poly(alumosiloxane)-bound ruthenium complexes A and B with various amounts of aluminum. From 31 P and 13 C CP MAS NMR as well as IR spectroscopy it can be concluded that the complex fragment cis-Cl(H)Ru(CO)(P∼O) 3 is preserved during the immobilization. Polymers A and B show a remarkable number of Si-O-Al bonds in the 29 Si solid state NMR spectra. The aluminum is incorporated as tetrahedrally coordinated AlO 4 units with a formal negative charge. The 6-fold coordinated AlO 6 groups containing water and hydroxide groups as ligands are sited as interstitials and act as their counterions. Stoichiometric formulas of A and B derived by 27 Al and 29 Si solid state NMR spectroscopy and energy dispersive X-ray spectroscopy (EDX) suggest that the amount of aluminum can be adjusted by the applied stoichiometry. The two materials A and B act as hydrogenation catalysts of transcrotylaldehyde and are easy to separate from the reaction mixture by simple centrifugation.

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