Structural, thermal, dielectric, nonlinear optical properties and DFT investigations of a novel material 2-(6-chloropyridin-3-yl)-N'-(2,3-dihydro-1,4-benzodioxin-6-ylmethylidene)acetohydrazide for optoelectronic applications

A new organic nonlinear optical (NLO) material 2-(6-chloropyridin-3-yl)-N'-(2,3-dihydro-1,4-benzodioxin-6-ylmethylidene)acetohydrazide (CDA) has been synthesized by reflux method. Single crystals were grown by slow evaporation technique and the crystal structure was elucidated by single crystal X-ray diffraction method. Density functional theory (DFT) calculations at B3LYP/6-31+ + G(d, p) basis set was used to predict the molecular geometry and were carried out further to comprehend the electronic structure, vibrational spectra, natural bonding orbitals (NBO), frontier molecular orbitals (FMO) and molecular electrostatic potential (MEP). An optical transparency at the cut-off wavelength of 355 nm was determined by UV-Vis-NIR spectroscopy. Thermal behavior of CDA was studied by TGA/DTA analysis. The dielectric constant (epsilon), dielectric loss (tan delta) and AC conductivity as a function of frequency and temperature was studied. Second Harmonic Generation (SHG) efficiency of the CDA was determined using Kurtz and Perry powder technique and was 0.5 times greater than that of the KDP crystal. The third-order nonlinear optical properties were investigated in solution by Z-scan technique using a continuous wave (CW) DPSS laser at the wavelength of 532 nm. The title compound exhibited significant two-photon absorption (beta = 2.228 x 10-4 cm W-1), nonlinear refraction (n(2) = 1.095 x 10-8 cm(2) W-1) and optical limiting (OL threshold = 2.511 x 103 W cm(-2)) under the CW regime. The nonlinear optical parameters were calculated using time-dependent Hartree-Fock (TDHF) method. The overall obtained results suggested that the studied CDA molecule could be a potential NLO material for frequency generator, optical limiters and optical switching applications.