Reactions of laser-ablated scandium atoms with nitrogen: Matrix infrared spectra and DFT calculations for scandium nitrides and the fixation of nitrogen by two scandium atoms

Laser-ablated Sc atoms react with nitrogen to form ScN, Sc(N-2) and (ScN)(2) and their N-2-ligated counterparts. These identifications are based on nitrogen-15 isotopic shifts and agreement with DFT vibrational frequency calculations. It is noteworthy that annealed argon matrix samples containing 2% N-2 give almost the same absorptions as nitrogen matrix samples for the ligated complexes (NN)(x)ScN and(ScN)(2)(NN)(x). The rhombic (ScN)(2) molecule is made by reaction of a second Sc atom with an intermediate ScN2 species and, thus, provides a method of nitrogen fixation with naked metal atoms.