Reactions of laser-ablated V, Cr, and Mn atoms with nitrogen atoms and molecules. Infrared spectra and density functional calculations on metal nitrides and dinitrogen complexes

Laser-ablated V, Cr, and Mn atoms mixed with Ar/N-2 and pure N-2 during condensation at 6-10 K produced and trapped the VN, CrN, and MnN molecules and their dinitrogen complexes. The M-N vibrations were characterized by nitrogen 14/15 isotopic ratios. Stepwise annealing converted the MN molecules into (NN)(x)MN complexes. The NCrN molecule was identified from nitrogen-14,15 and chromium-52,53,54 isotopic spectra. In addition to end-bonded M(NN)(x) complexes in the 2200-1900 cm(-1) region, evidence for side-bonded M(N-2) complexes was found in the 1900-1700 cm(-1) region. Density functional calculations provide support for the vibrational assignments.