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 2 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 2 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 2 ) 2 and thiazole-(CO 2 ) 3 complexes demonstrated the notable impact of C⋯N interactions on aggregation, with the significance of interactions between CO 2 molecules increasing with the number of CO 2 molecules present. NCI analysis, NBO analysis, and SAPT analysis were utilized to elucidate the properties of non-covalent interactions between thiazole and CO 2 , as well as those among CO 2 molecules.