Structural, spectroscopic, electronic, and nonlinear optical behavior investigations of π conjugated organic nonlinear optical chalcone derivative 3-(2,3-dichlorophenyl)-1-(pyridine-2-yl)prop-2-en-1-one using DFT

In this paper we have reported the computational studies of structural, spectroscopic and electronic behavior of a chalcone derivative: 3-(2,3- dichlorophenyl )-1-(pyridine-2- yl)prop-2-en-1-one (DCPP) nonlinear optical crystal. The geometry of DCPP molecule have been optimized using density functional theory (DFT) at B3LYP level having extended basis sets 6-311++G(d,p), 6-311+G(d,p), and 6-311G(d,p) with the help of Gaussian 09W program package. The structure parameters calculated with 6-311++G(d,p) basis set have shown best matching with experimental data having R2 value equal to 0.99. Taking this optimized geometry FTIR spectra were simulated and analyzed quantitatively with the help of calculated potential energy distribution (PED). For finding the reactivity sites and to understand electronic and optical behavior, natural bond orbital (NBO), the electrostatic potential surface map with isodensity surface, and HOMO-LUMO analysis were also presented. Finally, the nonlinear optical behavior of this calcone derivative was studied by calculating dipole moment (m), polarizability(a) and hyperpolarizability (b) values. The calculated hyperpolarizability btot of DCPP is 17.4593×10-30 esu which is about 90 times greater than urea (β= 0.1947× 10-30 esu). This higher value of hyperpolarizability btot confirms that the present molecule DCPP is a potential candidate for Nonlinear Optical applications.