N,N-dialkylcarbamato complexes as precursors for the chemical implantation of metal cations on a silica support.: Part 3 -: Palladium

Chemical implantation df palladium(II) has been carried but under mild conditions by reacting trans-Pd(O2CNEt2)(2)(NHEt2)(2) with the silanol groups of amorphous silica, carbon-dioxide and secondary amine being released in the process. The palladium-containing silica has been characterized and the coordination environment of the implanted cation has been defined by C-13 CP MAS NMR, DRIFT and-XPS spectra, and by WAXS measurements. Silica-bonded palladium(II) was reduced thermally in. vacuo or with dihydrogen at room temperature. Catalytic activity in the hydrogenation of cyclohexene was found for all samples containing the silica-supported reduced palladium; the best results, with rates independent of olefin concentration, were found for the samples treated thermally (200 degrees C) under reduced pressure.