in solid matrix an atomic beam of K (evaporized at 150°C) was codeposited with amixt. of CO2 and C(18)O2 in excess N2 onto a polished copper surface cooled to 15 K; period of deposition at about 1 h; identified by IR reflection spectrum;

CO2 in tetrahydrofuran Kinetics; W complex was treated with 1:1 mixt. of C- and O-labeled CO2 at -78°C; standing at 0°C; treating with excess of CO2 at -78°C; treating with aq. NEt4Br; extn. with Et2O; not isolated, determined by MS;

in neat (no solvent) C(18)O2 passing over Li salt at 500-550°C;

Irradiation (UV/VIS); 147 nm;

Irradiation (UV/VIS); 228.8 nm;