First principles study for the key electronic, optical and nonlinear optical properties of novel donor-acceptor chalcones

Using first-principle methods, several key electronic, optical and nonlinear optical properties are calculated for two recently synthesized chalcone derivatives i.e. (2E)-3-(4-methylphenyl)-1-(3-nitrophenyl)prop-2-en-1-one (comp.1) and (2E)-344-(dimethylamino)pheny11-1-(3-nitrophenyl)prop2-en-1-one (comp.2). The calculation of dipole moment, polarizability , anisotropy of polarizability as well as second hyperpolarizability (usually considered as a signature for two photon absorption phenomenon) are performed using density functional theory methods at PBEO/6-311G** level of theory. The linear average polarizability for comp.1 and comp.2 are found to be 32.15 x 10(-24) and 38.76 x 10(-24) esu, respectively. Similarly, the second hyperpolarizability amplitudes of comp.1 and comp.2 are found to be reasonably larger mounting to 79.31 x 10(-36) and 181.36 x 10(-36) esu, respectively. The importance of donor end is determined by comparing p-methylphenyl group of comp.1 with that of N,N-dimethylaniline group of comp.2 that results a remarkable increase in its amplitude, which is 2 times larger as compared with that of comp.1 owing to the stronger donor-acceptor configuration of comp.2. Interestingly, a comparison of average static third-order nonlinear polarizabilities shows that amplitudes of comp.1 and comp.2 are similar to 13 times and similar to 29 times larger than that of paranitroaniline (a typical standard push-pull NLO-phore) at the same PBEO/6-311G** level of theory, which indicates a real time NLO application of our titled compounds. Time dependent density functional theory (TD-DFT) calculations along with frontier molecular orbitals, density of states (DOS), second hyperpolarizability density analysis and molecular electrostatic potential (MEP) diagrams are used to trace the origin of electro-optical as well as structure property relationships. (C) 2016 Elsevier Inc. All rights reserved.