FT-IR, Laser-Raman spectra and quantum chemical calculations of methyl 4-(trifluoromethyl)-1H-pyrrole-3-carboxylate-A DFT approach Yusuf Sert a,b,⇑ , S. Sreenivasa c , H. Dog ˘an a , K.E. Manojkumar c , P.A. Suchetan c , Fatih Ucun d a Department of Physics, Faculty of Art & Sciences, Bozok University, Yozgat 66100, Turkey b Sorgun Vocational School, Bozok University, Yozgat 66100, Turkey c Department of Studies and Research in Chemistry, Tumkur University, Tumkur 572103, Karnataka (State), India d Department of Physics, Faculty of Art & Sciences, Süleyman Demirel University, Isparta 32100, Turkey highlights  The FT-IR and Laser-Raman spectra of the title compound were recorded in solid phase.  The optimized geometry and vibrational frequencies were calculated for the first time.  The HOMO–LUMO energies and related molecular properties were evaluated. graphical abstract article info Article history: Received 4 December 2013 Received in revised form 7 February 2014 Accepted 14 February 2014 Available online 26 February 2014 Keywords: FT-IR Laser-Raman DFT Vibration Pyrrole abstract In this study the experimental and theoretical vibrational frequencies of a newly synthesized anti-tumor and anti-inflammatory agent namely, methyl 4-(trifluoromethyl)-1H-pyrrole-3-carboxylate have been investigated. The experimental FT-IR (4000–400 cm 1 ) and Laser-Raman spectra (4000–100 cm 1 ) of the molecule in solid phase have been recorded. The theoretical vibrational frequencies and optimized geometric parameters (bond lengths, bond angles and torsion angles) have been calculated using density functional theory (DFT/B3LYP: Becke, 3-parameter, Lee–Yang–Parr and DFT/M06–2X: highly parameter- ized, empirical exchange correlation function) with 6-311++G(d,p) basis set by Gaussian 03 software, for the first time. The assignments of the vibrational frequencies have been done by potential energy distri- bution (PED) analysis using VEDA 4 software. The theoretical optimized geometric parameters and vibra- tional frequencies have been found to be in good agreement with the corresponding experimental data and results in the literature. In addition, the highest occupied molecular orbital (HOMO) energy, the low- est unoccupied molecular orbital (LUMO) energy and the other related molecular energy values of the compound have been investigated using the same theoretical calculations. Ó 2014 Elsevier B.V. All rights reserved. Introduction Pyrrole is one of the most significant heterocyclic structural scaffolds which present in a large number of biologically active http://dx.doi.org/10.1016/j.saa.2014.02.069 1386-1425/Ó 2014 Elsevier B.V. All rights reserved. ⇑ Corresponding author at: Department of Physics, Faculty of Art & Sciences, Bozok University, Yozgat 66100, Turkey. Tel.: +90 354 2421021; fax: +90 354 2421022. E-mail address: yusufsert1984@gmail.com (Y. Sert). Spectrochimica Acta Part A: Molecular and Biomolecular Spectroscopy 127 (2014) 122–130 Contents lists available at ScienceDirect Spectrochimica Acta Part A: Molecular and Biomolecular Spectroscopy journal homepage: www.elsevier.com/locate/saa