Reactions of Yttrium and Lanthanum Atoms with Nitrogen. Infrared Spectra of the Metal Nitrides and Dinitrogen Complexes in Solid Argon and Nitrogen

Abstract

Laser-ablated Y and La atoms react with nitrogen to produce metal nitrides and dinitrogen complexes, whereas thermally evaporated Y and La atoms form only dinitrogen complexes. The ligated mononitride complexes (NN)xYN and (NN)xLaN at 771.6 and 761.7 cm-1 in solid nitrogen are identified from nitrogen-15 shifts. These complexes predict gas-phase fundamentals near 800 and 790 cm-1 respectively for YN and LaN. The (YN)2 and (LaN)2 molecules and dinitrogen complexes are also identified from nitrogen-15 shifts and result from the reaction of two metal atoms with a single dinitrogen molecule involving the Y(N2) and La(N2) intermediate species. The same saturated (YN)2(NN)x and (LaN)2(NN)x dinitrogen complexes are prepared on annealing solid argon containing 2% N2 and deposition in pure nitrogen. The growth of ligated (YN)2(NN)x and (LaN)2(NN)x on annealing suggests that this nitrogen fixation reaction involves little activation energy.