Theoretical Investigation of Difluoroboron Complex of Curcuminoid Derivatives with and without Phenyl Substituent (at Meso Position): Linear and Non‐Linear Optical Study

Abstract

Two difluoroboron curcumin analogs and their phenylated versions were studied for their photophysical and non-linear optical properties based on comprehensive density functional theory approach. The ground state geometry optimization, vertical excitation, and the first excited state optimization were carried out using B3LYP and CAMÀ B3LYP functionals with 6-31G(d) basis set. The geometry of the difluoroboron curcumin analogs was found to remain planar in both the ground and excited states. The computed vertical excitation and emission values obtained with global hybrid functional are in good correlation with the observed values. The phenylated analogs show enhancement in the photophysical properties. The linear and non-linear optical properties were computed using two global hybrids functionals (B3LYP and BHHLYP) and a range separated hybrid functional (CAMÀ B3LYP) with 6-31 + G(d,p) basis set. The difluoroboron curcumin analogs without the phenyl substituent have larger polarizability and hyperpolarizabiliy parameters than the phenylated analogs. The polarizability and hyperpolarizabiliy were found to be comparable with the BHHLYP and CAMÀ B3LYP functionals.[a] M. M. Raikwar, Prof. N. Sekar

Synthesis, optical nonlinear properties, and all‐optical switching of curcumin analogues

“…From the mentioned facts about the importance of NLO properties in previous studies of curcumin and their analogues, [ 69–75 ] we have studied the NLO properties of curcumin analogues (Cur‐MeS and Cur‐MeO). The investigations of NLO characteristics on a theoretical‐level DFT/B3LYP and DFT/CAM‐B3LYP methods with 6‐311+G(2d,p) basis set have been used to generate several QCDs to investigate the NLO properties.…”

“…From the mentioned facts about the importance of NLO properties in previous studies of curcumin and their analogues, [69][70][71][72][73][74][75] we have studied the NLO properties of curcumin analogues (Cur-MeS and Cur-MeO). The investigations of NLO characteristics on a theoretical-level DFT/B3LYP and DFT/CAM-B3LYP The NLO characteristics increase as E LUMO , energy gap, ionization potential IE, and hardness decreases.…”

Polymethine Dyes Based on 2,2-Difluoro-1,3,2-dioxaborine: a Minireview

“…Generally, positive fluorochromism can be explained by higher energy requirement for the polar solvent to rearrange the solvate shell around the quadrupolar molecule during the relaxation from the Frank-Condon excited state S 1 FC to the relaxed state S 1 [102]. Since the excited state S 1 is more polar than the ground state S 0 and is characterized by the intramolecular charge transfer, enhancement of the electron donor power of the end-groups has an additional effect on the energy profile of relaxation S 1 FC → S 1 , which resulted in higher magnitudes of the Stokes shift [94,102,109].…”