REACTIONS OF LASER-ABLATED CO AND NI ATOMS WITH NITROGEN-ATOMS AND MOLECULES - INFRARED-SPECTRA AND DFT CALCULATIONS OF METAL NITRIDE MOLECULAR-SPECIES AND COMPLEXES

Laser-ablated Co and Ni atoms, co-deposited with pure nitrogen at 10 K , gave a strong new 795.3 cm(-1) band with cobalt and a 838.8, 836.1 c m(-1) isotopic doubler (2.5/1.0) with nickel, which exhibited 14/15 is otopic ratios appropriate for the diatomic CoN and NiN molecules. In s olid argon, CoN absorbs at 826.5 cm(-1) and gives way on annealing to bands at 795.8 and 792.0 cm(-1), which are due to (NN)(x)CoN complexes . Density functional theory (DFT) calculations predict quintet and qua rter ground states for CoN and NiN, respectively, and frequencies in r easonable agreement with the observed values. Evidence is also present ed for the dimetal dinitrides, (CoN)(2) and (NiN)(2), with rhombus str uctures and metal-metal bonding across the ring. DFT-based calculation s and revised assignments are presented for NI-NN stretching modes in the dinitrogen complexes.