NLO Properties of 3-Styryl Coumarin Derivatives - A Computational Approach

Siddheshwar D. Jadhav

Abstract: Coumarin-based fluorophores are known for their tunable optical characteristics. In this work, novel coumarin derivatives containing a 4-cyano group were synthesized and investigated for their nonlinear optical (NLO) properties. The presence of the cyano group enhanced intramolecular charge transfer and caused a red shift in absorption. Both experimental techniques and theoretical calculations were employed to evaluate their optical responses. First-order hyperpolarizability values were significantly high, ranging from 494 to 794 times that of urea, depending on the substituent's position. Solvent polarity was also found to influence the NLO behavior. These results highlight the potential of these compounds in future photonic and optoelectronic applications.

Keywords: 4-Cyano coumarin, DFT, TD-DFT, NLO