title: Vibrational spectroscopic studies, molecular orbital calculations and chemical reactivity of 6-nitro-m-toluic acid.
abstract: The potential energy surface scan for the selected dihedral angle of 6-nitro-m-toluic acid (NTA) has been performed to identify stable conformer. The optimized structure parameters and vibrational wavenumbers of stable conformer have been predicted by density functional B3LYP method with 6-311++G(d,p) basis set. The formation of dimer species through carboxylic acid group of the title molecule has also been discussed. The theoretical dimer geometries have been compared with that of monomer and the variations of bond lengths and bond angles upon dimerization were also discussed. Natural bond orbital (NBO) analysis has been performed on both monomer and dimer geometries. The significant changes in occupancies and the energies of bonding and anti-bonding orbitals upon dimerization have been explained in detail. The predicted frontier molecular orbital energies at B3LYP/6-311++G(d,p) method set show that charge transfer occurs within the molecule. The nucleophilic and electrophilic sites obtained from the molecular electrostatic potential (MEP) surface were compared with their derived fitting point charges. The vibrational wavenumbers of NTA affected profusely by the nitro group substitution in comparison to the toluic acid have been interpreted in this work.
authors.affiliation: Department of Physics, AA Government Arts College, Musiri, Tiruchirappalli, India. brsbala@rediffmail.com
authors.forename: V
authors.initials: V
authors.lastname: Balachandran
authors.forename: T
authors.initials: T
authors.lastname: Karthick
authors.forename: S
authors.initials: S
authors.lastname: Perumal
authors.forename: A
authors.initials: A
authors.lastname: Nataraj
mesh_terms: D001565:Benzoates / Q000737:chemistry*; D019281:Dimerization; D008958:Models, Molecular; D008968:Molecular Conformation; D009574:Nitro Compounds / Q000737:chemistry*; D017550:Spectroscopy, Fourier Transform Infrared
chemical_list: D001565:Benzoates; D009574:Nitro Compounds; C009503:3-toluic acid