π‐Electron delocalisation for intramolecular resonance assisted hydrogen bonds

Abstract π‐Electron delocalisation for the intramolecular resonance assisted hydrogen bonds (IRAHBs) is analysed here. The investigation is based on MP2/6‐311++G** calculations as well as on the results derived from the Bader theory. The Mulliken analysis of the change in natural population atomic charges for the IRAHB systems shows that there is a transfer of the electron charge from the R1CCR2CR3region into the OH…O hydrogen bond. The results of calculations also show that the strength of IRAHBs depends mainly on the process of the π‐electron delocalisation.