Carbon dioxide fixation by organolanthanides and thermal degradation into amorphous and higher condensed Ln/O/C/N solids

Ammine[tris(cyclopentadienyl)]-, amido[bis(cyclopentadienyl)]lanthanides, and tris[bis(trimethylsilylamido)]cerium have been studied with respect to CO2 absorption under various reaction conditions. Subsequent thermal treatment of these complexes under gaseous and supercritical CO2 yielded new higher condensed lanthanide Ln/O/C/N solids. IR spectroscopic studies of the CO2-activated species reveal the formation of various oxonitridocarbonates, in particular carbamates (O2CNH2-), imidocarbonates (O2CNH2-), isocyanates (OCN-), and carbonates (CO32-), which function as multidentate linkers between the lanthanide ions. Thereby, inorganic polymers are formed, which represent single-source precursors for application in various deposition methods and can therefore be utilized as pre-organized reagents in solid-state chemistry. In this context, we report on the structural characterization of one of the molecular precursors [Cp3YbNH3] [reticular pseudomerohedral twin, P2(1)/c, alpha = 826.8(2), b = 1103.8(2), c = 1482.0(3) pm, beta = 101.60(3)degrees, Z = 4, V = 1309.0(5)(.)10(6) pm(3)]. Crystals of [Cp3YbNH3] appear red, orange, yellow, and dark green depending on the orientation under plane-polarized light (pleochroism). ( Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2006).