ORIGINAL PAPER Vibrational spectra analysis, NBO, HOMO–LUMO, and nonlinear optical behavior studies on 3-(3,4- dimethoxyphenyl)-1-(pyridin-2-yl)prop-2-en-1-one Mahesh Pal Singh Yadav 1 • Anuj Kumar 1 • A. Jayarama 2 Received: 28 May 2015 / Accepted: 29 August 2015 / Published online: 29 September 2015 Ó Springer-Verlag Wien 2015 Abstract A combined experimental and theoretical study on molecular structure, vibrational spectra, HOMO– LUMO analysis, and hyperpolarizability of organic non- linear optical crystal 3-(3,4-dimethoxyphenyl)-1-(pyridin- 2-yl)prop-2-en-1-one is reported. Vibrational wavenumbers with Raman intensities and infrared absorption intensities have been calculated in the ground state by the density functional theory method using 6-31G(d,p) basis set and Becke’s three-parameter hybrid functional (B3LYP). Finally, the calculation results were applied to simulate infrared and Raman spectra of the title compound which showed good agreement with the observed spectra. The assignments of the vibrational spectra have been carried out with the aid of normal coordinate analysis. The natural bond orbital analysis was performed to study the intramolecular bonding, interactions among bonds, and delocalization of unpaired electrons. Electrostatic potential surface and HOMO–LUMO are reported along with global reactivity descriptors. First, hyperpolarizability of the molecule was also calculated and nonlinear behavior of the molecule analyzed using computed data. Graphical abstract Keywords Nonlinear optical crystal Á Hyperpolarizability Á DFT Á Natural bond orbital analysis Á HOMO–LUMO Introduction Chalcones are aromatic ketones that form the central core for a variety of important biological and nonlinear optical (NLO) compounds. Chalcones are abundant in edible plants [1], have relatively low redox potentials and have a greater probability of undergoing electron transfer reac- tions [2]. These compounds have attracted increasing attention due to numerous pharmacological applications [3–6]. These compounds exhibit good second harmonic generation (SHG) efficiency, excellent blue light trans- mittance [7, 8], good crystallizability [9–12], better optical limiting behavior with nanosecond laser pulses at 532 nm wavelength [13], and ultrafast optical nonlinearities at 780 nm [14]. Studies on chalcones suggest that the second- order molecular nonlinearity can be enhanced by large delocalized p-electron systems with strong donor and acceptor groups [15]. The basic strategy of using electron & Anuj Kumar anujkumar.jiet@gmail.com; anuj.kumar@juet.ac.in 1 Department of Physics, Jaypee University of Engineering and Technology, Raghogarh, Guna 473 226, India 2 Department of Physics, Sahyadri College of Engineering and Management, Mangalore, India 123 Monatsh Chem (2016) 147:1045–1061 DOI 10.1007/s00706-015-1567-8