title: Spectroscopic investigation, natural bond orbital analysis, HOMO-LUMO and thermodynamic functions of 2-tert-butyl-5-methyl anisole using DFT (B3LYP) calculations.
abstract: The optimized molecular structure and corresponding vibrational assignments of 2-tert-butyl-5-methyl anisole (TBMA) have been investigated using density functional theory (DFT)/B3LYP with 6-31G(d,p) and 6-311++G(d,p) basis sets investigation of the relative orientation of the methoxy group has shown two conformers (O-cis) and (O-trans) exist. The vibrational analysis of the stable conformer of the title compound is performed by means of infrared absorption and Raman spectroscopy in combination with theoretical simultaneously. The natural bond orbital (NBO) analysis is useful to understand the intra-molecular hyper conjugative interaction lone pair and π(∗)(C-C), σ(∗)(C-H) bond orbital. HOMO and LUMO energies show that charge transfer occurs in the molecule, therefore; HOMO, LUMO and molecular electrostatic potential (MEP) were calculated and analyzed. (1)H and (13)C NMR spectra by using gauge including atomic orbital (GIAO) method of studied compound were compared with experimental data. The thermodynamic functions of TBMA were calculated by B3LYP/6-311+G(d,p) basis set.
authors.affiliation: Centre for Research, Department of Physics, AA Government Arts College, Musiri, Tiruchirappalli 621211, India. Electronic address: brsbala66@gmail.com.
authors.forename: V
authors.initials: V
authors.lastname: Balachandran
authors.affiliation: Department of Physics, Government Arts College, Karur 639005, India.
authors.forename: G
authors.initials: G
authors.lastname: Santhi
authors.affiliation: Department of Physics, Srinivasan Polytechnic College, Perambalur 621212, India.
authors.forename: V
authors.initials: V
authors.lastname: Karpagam
authors.affiliation: Centre for Research, Department of Physics, AA Government Arts College, Musiri, Tiruchirappalli 621211, India.
authors.forename: B
authors.initials: B
authors.lastname: Revathi
authors.affiliation: Department of Mechatronics Engineering, H.F.T. Technology Faculty, Celal Bayar University, 45400 Turgutlu, Manisa, Turkey.
authors.forename: M
authors.initials: M
authors.lastname: Karabacak
mesh_terms: D000840:Anisoles / Q000737:chemistry*; D066241:Carbon-13 Magnetic Resonance Spectroscopy; D004583:Electrons; D008958:Models, Molecular; D008968:Molecular Conformation; D066244:Proton Magnetic Resonance Spectroscopy; D011789:Quantum Theory; D012399:Rotation; D017550:Spectroscopy, Fourier Transform Infrared; D013059:Spectrum Analysis, Raman; D055672:Static Electricity; D013816:Thermodynamics; D014732:Vibration
chemical_list: D000840:Anisoles; C060998:anisole
keywords: 2-tert-butyl-5-methyl anisole; DFT; HOMO–LUMO; NBO; Thermodynamic functions; Vibrational spectra