Spectroscopic investigations, NBO, HOMO–LUMO, NLO analysis and molecular docking of 5-(adamantan-1-yl)-3-anilinomethyl-2,3-dihydro- 1,3,4-oxadiazole-2-thione, a potential bioactive agent Fatmah A.M. Al-Omary a , Y. Sheena Mary b , C. Yohannan Panicker c,⇑ , Ali A. El-Emam a , Ibrahim A. Al-Swaidan a , Abdulaziz A. Al-Saadi d , C. Van Alsenoy e a Department of Pharmaceutical Chemistry, College of Pharmacy, King Saud University, Riyadh 11451, Saudi Arabia b Department of Physics, Fatima Mata National College, Kollam, Kerala, India c Department of Physics, TKM College of Arts and Science, Kollam, Kerala, India d Department of Chemistry, King Fahd University of Petroleum and Minerals, Dhahran 31261, Saudi Arabia e Structural Chemistry Group, Department of Chemistry, University of Antwerp, Groenenborgerlaan 171, B-2020 Antwerp, Belgium highlights  Spectroscopies properties were examined by FT-IR and FT-Raman spectra.  The complete vibrational assignments are made on the basis of potential energy distribution.  NBO analysis and HOMO and LUMO energies are predicted.  Molecular docking predicts inhibitory activity against PPARa. graphical abstract article info Article history: Received 9 February 2015 Received in revised form 17 February 2015 Accepted 24 March 2015 Available online 7 April 2015 Keywords: DFT Adamantane FT-IR FT-Raman Molecular docking abstract The optimized molecular structure, vibrational frequencies, corresponding vibrational assignments of 5-(adamantan-1-yl)-3-anilinomethyl-2,3-dihydro-1,3,4-oxadiazole-2-thione have been investigated experimentally and theoretically. The geometrical parameters are in agreement with XRD data. The sta- bility of the molecule arising from hyper-conjugative interaction and charge delocalization has been ana- lyzed using NBO analysis. The frontier molecular orbital analysis is used to determine the charge transfer within the molecule. As can be seen from the MEP map of the title molecule, the negative region are mainly localized over the C@S and the CH 2 group attached to the oxadiazole ring and the maximum posi- tive region is localized near the NH group. The first and second order hyperpolarizability values are also calculated theoretically. The title compound forms a stable complex with PPARa as is evident from the binding affinity values and the results suggest that the compound might exhibit inhibitory activity against PPARa and this may result in development of new anti-diabetic (Type 2) agents. Ó 2015 Published by Elsevier B.V. Introduction Considerable attention has been devoted to adamantane deriva- tives which have long been known for their diverse biological http://dx.doi.org/10.1016/j.molstruc.2015.03.049 0022-2860/Ó 2015 Published by Elsevier B.V. ⇑ Corresponding author. Tel.: +91 9895370968. E-mail address: cyphyp@rediffmail.com (C.Y. Panicker). Journal of Molecular Structure 1096 (2015) 1–14 Contents lists available at ScienceDirect Journal of Molecular Structure journal homepage: www.elsevier.com/locate/molstruc