Synthesis and Study of Structural and Vibrational Spectral Contributions to the Nonlinear Optical Properties of (2E)-2- (3,4-Dimethoxybenzylidene)-3,4-dihydronaphthalen-1(2H)- one

Abstract

The chalcone derivative (2E)-2-(3,4-Dimethoxybenzylidene)-3,4-dihydronaphthalen-1(2H)-one was synthesized and single crystals were grown by slow evaporation technique. Its structure was examined by X-ray diffraction analysis and investigated theoretically as well as experimentally to examine its nonlinear optical (NLO) behaviour. Density Functional Theory was used to obtain the theoretical calculations using Gaussian 09W program package. Cc-pVTZ level of theory was used to obtain the geometry optimization of the title compound. The calculated optimized parameters were tabulated. The vibrational spectral analysis of the compound have been carried out using the experimental and computational FT-IR evaluation. The theoretical and experimental cut off wavelength, corresponding to electronic transitions are obtained. The most important hyper conjugative interactions leading to the stability and intramolecular charge transfer of the compound is sort out by natural bond orbital analysis. The active frontier molecular orbitals play a part in the electronic transitions were identified. The nonlinear optical behaviour was investigated theoretically and third order nonlinearity of (2E)-2-(3,4- Dimethoxybenzylidene)-3,4-dihydronaphthalen-1(2H)-one crystal, measured from z-scan studies, conducted in continuous wave excitation regime was also done.