Nature and Strength of M–H···S and M–H···Se (M = Mn, Fe, & Co) Hydrogen Bond

• Published in: The journal of physical chemistry. A, Molecules, spectroscopy, kinetics, environment, & general theory Molecules, spectroscopy, kinetics, environment, & general theory, 2019-03, Vol.123 (11), p.2227-2236
• Main Authors: Sahoo, Dipak Kumar, Jena, Subhrakant, Dutta, Juhi, Rana, Abhijit, Biswal, Himansu S
• Format: Article
• Language: English
• ISSN: 1089-5639; 1520-5215
• DOI: 10.1021/acs.jpca.8b12003

The significance of dispersion contribution in the formation of strong hydrogen bonds (H-bonds) can no more be ignored. It was illustrated that less electronegative and electropositive H-bond acceptors such as S, Se, and Te are also capable of forming strong N–H···Y H-bonds, mostly due to the high polarizabilities of H-bond acceptor atoms. Herein, for the first time, we report the evidence of formation of nonconventional M-H···Y H-bonds between metal hydrides (M-H, M = Mn, Fe, Co) and chalcogen H-bond acceptors (Y = O, S, or Se). The nature and the strength of unusual M-H···Y H-bonds were revealed by several quantum chemical calculations and H-bond descriptors. The structural parameters, electron density topology, donor–acceptor natural bond orbital (NBO) interaction energies, and spectroscopic observables such as M-H stretching frequencies and 1H chemical shifts are well-correlated to manifest the existence and strength of M-H···Y H-bonding. The M-H···Y H-bonds are dispersive in nature, and the computed H-bond energies are found to be in the range from ∼5 to 30 kJ/mol, which can be compared to those of the conventional H-bonds such as O–H···O, N–H···O, and N–H···OC H-bonds, etc.