Quantum chemical computational and spectroscopic (IR, Raman, NMR, and UV) studies on the 5-(5-methoxy-benzofuran-3-ylmethyl)- 3H-[1, 3, 4] oxadiazole-2-thione Sudhir M. Hiremath a , Seema S. Khemalapure a , Chidanandayya S. Hiremath b, * , Anil S. Patil a , Mahantesha Basanagouda c, ** a Department of Physics, K.L.E. Dr. M.S. Sheshgiri College of Engineering and Technology, Belagavi, 590008, Karnataka, India b Department of Physics, S.K. Arts and H.S.K. Science Institute, Hubballi, 580031, Karnataka, India c Department of Chemistry, P.C. Jabin Science College, Hubballi, 580031, Karnataka, India article info Article history: Received 30 September 2019 Received in revised form 7 March 2020 Accepted 8 March 2020 Available online 9 March 2020 Keywords: DFT FT-IR FT-Raman Fukui function NMR UV abstract This research article describes the quantum chemical computational and spectroscopic (IR, Raman, NMR, and UV) studies on the 5-(5-methoxy-benzofuran-3-ylmethyl)-3H-[1, 3, 4] oxadiazole-2-thione (55MBOT). The research work is conducted in two levels. Initially, experimental FT-IR, FT-Raman, NMR ( 13 C, 1 H) chemical shift and UVeVis spectral data are recorded. After that, the theoretical computational analysis have been performed by DFT/B3LYP/6e311þþG (d, p) basis level. The optimization of the 55MBOT is conducted to obtain the standard molecular structure. The theoretical FT-IR and FT-Raman wavenumbers obtained from the DFT/B3LYP/6e311þþG (d, p) basis level and compared with experi- mental data. The detailed vibrational assignments are obtained with the help of potential energy dis- tribution (PED). The experimental NMR chemical shifts are compared with computed NMR data. In addition, several analyses such as NBO, NLO, FMO MEP, Fukui function and thermodynamic properties have been conducted to determine the nature of the 55MBOT. © 2020 Elsevier B.V. All rights reserved. 1. Introduction Benzofuran is an elemental, organic unit in different natural and biologically active products [1,2]. Benzofurans are formed by fusing the benzene and furan rings. Benzofuran moieties have a wide variety of pharmacological characteristics such as anti-Alzheimer’s disease, anti-viral, anti-cancer, anti-bacterial, anti-parasitic, and anti-TB activities [3]. Benzofurans are also familiar in the field of material science owing to their blue light-emitting, high quantum yields, thermal stability, and electrochemical behavior [4e6] properties. The 1,3,4-oxadiazole is a heterocyclic compound, which has vital physical properties and significant biological activity because of its involvement in hydrogen bonding interactions with different receptors [7]. The 1,3,4-oxadiazole moieties exhibit some essential biological activities such as anticancer, antiepileptic, antimicrobial, antiallergic, antitubercular, and anticonvulsant ac- tivities [8]. The various applications as mentioned above, it has created interest in the title molecule. The detailed literature review reveal that there have been no experimental and theoretical studies re- ported on the 5-(5-methoxy-benzofuran-3-ylmethyl)-3H-[1, 3, 4] oxadiazole-2-thione (55MBOT) molecule. Hence we have per- formed various experimental and theoretical spectroscopic, mo- lecular orbital, optical, electronic and thermodynamic properties analyses on the present molecule. 2. Materials and methods 2.1. Experimental details The 5-(5-methoxy-benzofuran-3-ylmethyl)-3H-[1, 3, 4] oxa- diazole-2-thione (55MBOT) molecule is synthesized according to the literature [8]. The FT-IR spectrum has been recorded in Perki- nElmer Spectrometer in the sort 4000-400 cm 1 . The FT-Raman spectrum also carried out with same instrument in the region of * Corresponding author. ** Corresponding author. E-mail addresses: hiremathc@gmail.com (C.S. Hiremath), mahanteshachem@ gmail.com (M. Basanagouda). Contents lists available at ScienceDirect Journal of Molecular Structure journal homepage: http://www.elsevier.com/locate/molstruc https://doi.org/10.1016/j.molstruc.2020.128041 0022-2860/© 2020 Elsevier B.V. All rights reserved. Journal of Molecular Structure 1210 (2020) 128041