Hydrogen bonds and other interactions as a response to protect doublet/octet electron structure.

MP2/aug-cc-pVTZ calculations were performed for complexes linked by hydrogen bonds. Three types of proton donating species were taken into account: HO, CClH, and HO. These calculations are supported by the natural bond orbital (NBO) method and the quantum theory of atoms in molecules (QTAIM) approach. Numerous correlations between parameters of H-bonded systems were found. The most important are those which show the response of the system on the H-bond formation; for example, the increase of polarization of the A-H bond correlates with the strength of the hydrogen bond. Similar relationships were found for the σ-hole bonds while the π-hole bonds do not follow the trends known for the hydrogen bonds. Graphical abstract Hydrogen bonds and other interactions as a response to protect doublet/octet electron structureᅟ.