Elucidating the non-covalent interactions in thiazole-carbon dioxide complexes through rotational spectroscopy and theoretical computations.

The complexes formed between thiazole and carbon dioxide were studied to probe the non-covalent bonding properties between carbon dioxide and a heteroaromatic ring. The rotational spectra of the thiazole-CO complex were analyzed using a supersonic jet Fourier transform microwave spectrometer in conjunction with theoretical calculations. A rotational spectrum corresponding to the global minimum of the thiazole-CO complex was identified. The observed structure of the complex is stabilized by a C⋯N tetrel-bond, with additional stability provided by a C-H⋯O hydrogen bond. The computational analysis of the thiazole-(CO) and thiazole-(CO) complexes demonstrated the notable impact of C⋯N interactions on aggregation, with the significance of interactions between CO molecules increasing with the number of CO molecules present. NCI analysis, NBO analysis, and SAPT analysis were utilized to elucidate the properties of non-covalent interactions between thiazole and CO, as well as those among CO molecules.