Journal of Computational Science 10 (2015) 237–246 Contents lists available at ScienceDirect Journal of Computational Science journa l h om epage: www.elsevier.com/locate/jocs Synthesis, spectroscopic characterization, electronic and optical studies of (2Z)-5,6-dimethyl-2-[(4-nitrophenyl)methylidene]-2,3- dihydro-1-benzofuran-3-one Diwaker a , C.S.Chidan Kumar b,c , Ashish Kumar a , Siddegowda Chandraju d,∗ , Ching Kheng Quah b , Hoong-Kun Fun b,e,∗∗ a School of Basic Sciences, Indian Institute of Technology Mandi, Mandi, HP 175005, India b X-ray Crystallography Unit, School of Physics, Universiti Sains Malaysia (USM), 11800 Penang, Malaysia c Department of Chemistry, Alva’s Institute of Enginering & Technology, Mijar, Moodbidri 574225, Karnataka, India d Department of Sugar Technology & Chemistry, University of Mysore, Sir M.V. PG Center, Tubinakere, Mandya 571 402, Karnataka, India e Department of Pharmaceutical Chemistry, College of Pharmacy, King Saud University, Riyadh 11451, Saudi Arabia a r t i c l e i n f o Article history: Received 13 October 2014 Received in revised form 15 November 2014 Accepted 18 November 2014 Available online 16 December 2014 Keywords: Crystal structure Molecular geometry Optical properties Band structure a b s t r a c t The title compound, (2Z)-5,6-dimethyl-2-[(4-nitrophenyl) methylidene]-2,3-dihydro-1-benzo furan-3- one, has been synthesized and characterized using experimental (XRD) and theoretical methods (FTIR, NMR, electronic and optical studies). The compound crystallizes in monoclinic space group P2 1 /c with a = 7.527 (7) Å, b = 15.9397(15) Å, c = 13.5106 (10) Å, ˇ = 117.649 (4) ◦ and Z = 4. The initial coordinate geom- etry obtained by XRD is further used to obtain the optimized ground state geometry of the title compound using DFT/B3LYP/6-311++G (2d,2p) level of theory. Geometrical parameters, vibration frequencies, Gauge invariant atomic orbital (GIAO) 1 H and 13 C NMR chemical shifts of the title compound have been calculated theoretically using the optimized ground state geometry. Apart from this, density of states of different atoms, band gap studies and optical properties have also been studied successfully using theoretical models. © 2014 Elsevier B.V. All rights reserved. 1. Introduction Combining crystallography with molecular modelling has gained popularity in the recent years for characterization of molecules and to explore their physical and chemical properties. DFT, HF and MP2 along with other modelling methods are widely used in the theoretical modelling of molecules to understand the physical and chemical properties. We have explored the title com- pound by both experimental and theoretical methods to throw light on some of its properties which can be used for development of advanced applications. The title compound is an aurone type. Claisen–Schmidt reaction is one of the most important reactions for the synthesis of donor–acceptor conjugated dienes, known as chalcones [1]. Chalcones are precursors of open chain flavonoids and isoflavonoids, which are abundant in edible plants. It is ∗ Corresponding author. Tel.: +91 8232 291112; fax: +91 8232 291111. ∗∗ Corresponding author. E-mail addresses: chandraju1@yahoo.com (S. Chandraju), hfun.c@ksu.edu.sa, hkfun@usm.my (H.-K. Fun). generally synthesized by the reaction of acetophenone and benzal- dehyde in acidic [2] and basic medium [3,4]. Chalcones are the class of active compounds that have displayed a broad spectrum of phar- macological activities such as anti-oxidant [5], anti-inflammatory, antibacterial, anticancer, anti-allergic, antimalarial, antiviral and antifungal agents. In recent years, chalcones have been used in the field of material science as non-linear optical (NLO) mate- rial because chalcone derivatives are notable materials for their second harmonic generation (SHG). Researchers have reported different synthetic methods, such as, refluxing in an organic sol- vent [6], the solvent-free solid-phase reaction [7], ultra sonication [8], photosensitization [9] and microwave radiation [10]. Minor changes in their skeletal structure have offered a high degree of diversity that has proven useful for the development of new antiox- idants having improved potency and lesser toxicity. In addition, the nucleus has been found to be used as antioxidant in a wide range of formulations targeting for the anti-aging activity. Aurones, (Z)-2-benzylidenebenzofuran-3-(2H)-ones, constitute a less stud- ied subclass of flavonoids, which occur rarely in nature: to date a few aurones have been reported that were obtained from natu- ral sources, mainly flowering plants, and a few ferns, mosses and http://dx.doi.org/10.1016/j.jocs.2014.11.005 1877-7503/© 2014 Elsevier B.V. All rights reserved.