title: FT-IR, FT-Raman, NMR, UV and quantum chemical studies on monomeric and dimeric conformations of 3,5-dimethyl-4-methoxybenzoic acid.
abstract: Extensive spectroscopic investigations along with theoretical quantum chemical studies on 3,5-dimethyl-4-methoxybenzoic acid (DMMBA) have been consummated. The fundamental vibrational transitions were addressed by experimental FT-IR (4000-400cm(-1)) and FT-Raman (4000-10cm(-1)) techniques and density functional calculations at B3LYP/6-311++G(d,p) and B3LYP/6-311++G(df,pd) levels of theory. The (1)H, (13)C and DEPT 135 NMR spectra of studied compound were recorded in deuterated dimethylsulfoxide (DMSO-d6), and compared with computed data obtained by using gauge including atomic orbital (GIAO) method. The electronic absorption spectra in methanol and ethanol solution were evaluated in the range of 200-400nm, and TD-DFT method was chosen for computational study. The spectroscopic and theoretical results were compared to the corresponding properties for monomer and dimer structures for the most stable conformer. Stability of the molecule arising from hyperconjugative interactions and charge delocalization has been analyzed using natural bond orbital (NBO) analysis. Moreover, the thermodynamic and nonlinear optical (NLO) properties were evaluated.
authors.affiliation: Department of Mechatronics Engineering, H.F.T. Technology Faculty, Celal Bayar University, Turgutlu, Manisa, Turkey. Electronic address: mehmet.karabacak@cbu.edu.tr.
authors.forename: Mehmet
authors.initials: M
authors.lastname: Karabacak
authors.affiliation: Department of Physics, University of Lucknow, Lucknow, India.
authors.forename: Leena
authors.initials: L
authors.lastname: Sinha
authors.affiliation: Department of Physics, University of Lucknow, Lucknow, India.
authors.forename: Onkar
authors.initials: O
authors.lastname: Prasad
authors.affiliation: Department of Chemistry, Faculty of Science, King Abdulaziz University, Jeddah, Saudi Arabia; Center of Excellence for Advanced Materials Research, King Abdulaziz University, Jeddah, Saudi Arabia.
authors.forename: Abdullah M
authors.initials: AM
authors.lastname: Asiri
authors.affiliation: Department of Science Education, Bayburt University, Bayburt, Turkey.
authors.forename: Mehmet
authors.initials: M
authors.lastname: Cinar
authors.affiliation: Department of Physics, University of Lucknow, Lucknow, India.
authors.forename: Vikas K
authors.initials: VK
authors.lastname: Shukla
mesh_terms: D019281:Dimerization; D062425:Hydroxybenzoate Ethers / Q000737:chemistry*; D009682:Magnetic Resonance Spectroscopy; D008745:Methylation; D008958:Models, Molecular; D011789:Quantum Theory; D012459:Salicylates / Q000737:chemistry*; D013056:Spectrophotometry, Ultraviolet; D017550:Spectroscopy, Fourier Transform Infrared; D013059:Spectrum Analysis, Raman
chemical_list: D062425:Hydroxybenzoate Ethers; D012459:Salicylates; C081914:2-methoxybenzoic acid
keywords: 3,5-Dimethyl-4-methoxybenzoic acid; DFT; FT-IR and FT-Raman spectra; NLO and NBO analysis; UV and NMR spectra