Shahriar Ahmed

Abstract

An azo-hydrazone derivative, 4-((E)-phenyldiazenyl)-2-((E)-(2-phenylhydrazono)methyl)phenol (PDPMP), was synthesized and characterized using FT-IR, UV–Vis, NMR, and LC-MS. Its structural, electronic, and nonlinear optical (NLO) properties were examined via DFT and TD-DFT at the B3LYP/6–311++G(d,p) level with the IEFPCM solvent model. The influence of solvent polarity on electronic transitions, charge transfer, NLO response, and antagonist activity was explored systematically. Solvent polarity significantly altered UV–Vis absorption, HOMO–LUMO gap, charge-transfer behavior, and NLO efficiency. PDPMP exhibited first-order hyperpolarizability (βtotal) of 537 × 10⁻³¹ esu, which is approximately 69 times greater than the reference value for urea (βtotal = 7.803 × 10⁻³¹ esu) and 3.5 time than p-nitroaniline (βtotal = 155 × 10–31 esu) and increasing up to threefold in polar solvents with notable positive solvatochromism. NTO and TDM analyses confirmed solvent-induced intramolecular charge transfer, while NBO and RDG analyses revealed orbital delocalization and noncovalent interactions. Molecular docking against Mcl-1 (PDB IDs: 4HW3, 6GL8) suggested that PDPMP has higher binding affinity than the preclinical drug Obatoclax. These findings suggest that it may serve as a dual-function NLO material and merit additional investigation for its potential as an anticancer agent.