Using Quantum Chemistry for Interpreting the IR Spectra of Chemisorbed Gases

Our paper: Computations of IR spectra of some transition metal carbonyls and model clusters of nickel oxide with carbon monoxide. Journal of Molecular Structure1241(11):130439. DOI:10.1016/j.molstruc.2021.130439

We investigated some carbonyls, compounds like this:

We computed the IR spectra of several carbonyls and built the correlation between the theoretical and experimental positions of the bands corresponding to CO-stretching mode:

The marked points are not carbonyls but a Ni4O4..CO complex which serves as a model for CO chemisorbed on nicked oxide. These correlations allow us to confirm the 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.