Infrared photodissociation spectroscopy of M(N2)n+ (M = Y, La, Ce; n = 7–8) in the gas phase

Abstract

M(N₂)_n⁺ (M = Y, La, Ce; n = 7–8) complexes have been studied by infrared photodissociation (IRPD) spectroscopy and density functional theory (DFT) calculations. The experimental results indicate that the N–N stretching vibrational frequencies are red-shifted from the gas-phase N₂ value. The π back-donation is found to be a main contributor in these systems. IRPD spectra and DFT calculations reveal the coexistence of two isomers in the seven-coordinate M(N₂)₇⁺ and eight-coordinate M(N₂)₈⁺ complexes, respectively. The present studies on these metal–nitrogen complexes shed light on the interactions and coordinations toward N₂ with transition and lanthanide metals.