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The preparations of the N,N-dialkylcarbamato complexes with analytical formulae [Ln(O2CNR2)3] (Ln = Pr, Nd, Eu, Gd, Ho, Er, Yb, Lu, R = iPr; Ln = Nd, Eu, Gd, R = Bu; Ln = Nd, R = Et), using [LnCl3(ether)x] (ether = THF or dimethoxyethane, DME), NHR2, and CO2 are reported. X-ray diffraction of the diisopropylcarbamato derivatives, including a reinvestigation of [Yb4(O2CNiPr2)12], showed these complexes to be tetranuclear and isotypical over a range of 12 atomic numbers. The lanthanide contraction has been evaluated based on the lengths of four different types of Ln−O bond. (© Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2004)

Chemical implantation of palladium(II) has been carried out 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 13C 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°C) under reduced pressure.