The (E)-2-(2-hydroxybenzylidenamino)-3-(1H-indol-3yl) propionic acid ((E)-2HBA3IPA) was synthesized. The theoretical conformational analysis was performed to identify the stable structure. Optimized molecular bond parameters were calculated by using B3LYP/6-31G(d,p) basis set. The hyperconjugative interaction energy (E-(2)) and electron densities of donor (i) and acceptor (j) bonds were calculated using NBO analysis. First order hyperpolarizability (beta(o)) was calculated. The band gap energy was analyzed by UV-Visible recorded spectra and compared with theoretical band gap TD-DFT/B3LYP/6-31G(d,p) values. The intra-molecular hydrogen bonding interaction was identified between nitrogen and hydroxyl hydrogen (N center dot center dot center dot H-O). (C) 2012 Elsevier B.V. All rights reserved.