Computations of IR spectra of some transition metal carbonyls and model clusters of nickel oxide with carbon monoxide

Abstract Using the PBE/6-31G(d), B3LYP-D3/6-31G(d), wB97XD/6-31G(d), PBE/aug-cc-pVTZ levels, DFT calculations of the structure and IR spectra of a number of transition metal carbonyls were performed. We also studied the Ni4O4..CO cluster, which was used as a model for predicting the properties of carbon monoxide chemisorbed on nickel oxide. The general correlation constructed for these species between the calculated and experimental positions of the bands in the spectrum corresponding to the CO stretching vibration allowed us to confirm an earlier assumption that the IR spectrum bands above 2000 cm–1 correspond to CO bound to the metal atom linearly, and bands below 2000 cm–1 correspond to CO forming a bridged bond with two metal atoms. The assumption by Alexeyev et al. that the 1925 cm–1 band in the experimental spectrum corresponds to a structure in which the carbon atom CO is bonded to the metal atom and the oxygen atom of the nickel oxide surface has not been confirmed.