Substituent-Driven Modulation of Electronic Properties in Acrylonitrile Derivatives: A Combined Study on NLO Response and DNA-Binding Affinity via ECT Analysis

Özen F., Gündüz B., Turgut Cin G., Babali Özen L., Ekici Ö.

INTERNATIONAL JOURNAL OF QUANTUM CHEMISTRY, vol.126, pp.70289-70308, 2026 (SCI-Expanded, Scopus)

  • Publication Type: Article / Article
  • Volume: 126
  • Publication Date: 2026
  • Doi Number: 10.1002/qua.70289
  • Journal Name: INTERNATIONAL JOURNAL OF QUANTUM CHEMISTRY
  • Journal Indexes: Academic Search Ultimate (EBSCO), Engineering Source (EBSCO), Scopus, Materials Science & Engineering Collection (ProQuest), Technology Collection (ProQuest), Science Citation Index Expanded (SCI-EXPANDED), Chemical Abstracts Core, Chimica, Compendex, INSPEC, zbMATH
  • Page Numbers: pp.70289-70308
  • Akdeniz University Affiliated: Yes

Abstract

This study presents a systematic investigation into the substituent-driven modulation of the electronic, optical, and biological properties of two methoxy-substituted acrylonitrile derivatives, denoted as C-1 (m-CF3 substituted) and C-2 (p-CH3 substituted). While experimental data revealed a striking parity in their optical band gaps (Eg = 3.3 eV in DMSO), their distinct electronic profiles prompted a deeper theoretical probe to differentiate their microscopic performances. Density Functional Theory (DFT) calculations at the B3LYP/6–311++G(d,p) level for ground-state properties and B3LYP/6–311G(d,p) for TD-DFT calculations were employed to elucidate the underlying electronic mechanisms. Natural Bond Orbital (NBO) analysis demonstrated that both systems exhibit efficient intramolecular charge transfer (ICT) across the acrylonitrile bridge. Furthermore, range-separated hybrid DFT calculations (CAM-B3LYP/6–311++G(d,p)) were performed to accurately evaluate the non-linear optical (NLO) responses without global hybrid overpolarization artifacts. The calculations revealed comparable, robust first-order hyperpolarizabilities (mathematical equation) for both derivatives (mathematical equation for C-1 and mathematical equation for C-2 in DMSO), significantly exceeding the benchmark urea threshold. To explore the theoretical quantum-chemical reactivity profiles of these chromophores, Electrophilicity Charge Transfer (ECT) analysis was utilized to model their charge-transfer tendencies with DNA bases. The results indicate that the electron-withdrawing mathematical equation group in C-1 enhances its electrophilic character, suggesting a higher charge-accepting propensity toward nucleophilic bases. By correlating photophysical response with theoretical charge-transfer descriptors, this work provides crucial mechanistic insights into the design of multifunctional materials suitable for non-linear optical (NLO) applications and electronic structure tuning.