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.