TD-DFT investigation of the potential energy surface for Excited-State Intramolecular Proton Transfer (ESIPT) reaction of 10-hydroxybenzo[h]quinoline: Topological (AIM) and population (NBO) analysis of the intramolecular hydrogen bonding interaction

► Theoretical modelling of the photophysics of an ESIPT probe 10-hydroxybenzo[h]quinoline (HBQ). ► Calculation of intramolecular hydrogen bond (IMHB) energy. ► Role of hyperconjugative charge transfer interaction in IMHB assessed by NBO perspective. ► Topological properties of IMHB analyzed from AIM view point. ► Computational results are assayed from direct comparison with experimental reports.