title: Vibrational analysis and valence force field for nitrotoluenes, dimethylanilines and some substituted methylbenzenes.
abstract: The Fourier transform infrared (FTIR) and Raman spectra of 2-amino-4-nitrotoluene; 2-amino-5-nitrotoluene; 2,4-dimethylaniline; 2,5-dimethylaniline; 2,6-dimethylaniline; 1,2,4-trimethylbenzene; 1,3,5-trimethylbenzene and pentamethylbenzene have been recorded in the range 4000-400 cm(-1) and 4000-30 cm(-1), respectively. A normal coordinate analysis was carried out for both in-plane and out-of-plane vibrations of these molecules using an 81-parameter modified valence force field. The force constants were refined using 369 frequencies of eight molecules in the overlay least-squares technique. The reliability of the force constants was tested by making a zero-order calculation for both in-plane and out-of-plane vibrations for five related molecules. The potential energy distributions and eigen vectors calculated in the process were used to make unambiguous vibrational assignments of all the fundamentals.
authors.affiliation: Department of Physics, Government Degree & P.G. College, Mancherial 504208, A.P., India.
authors.forename: Jai Kishan
authors.initials: JK
authors.lastname: Ojha
authors.forename: B
authors.initials: B
authors.lastname: Venkatram Reddy
authors.forename: G
authors.initials: G
authors.lastname: Ramana Rao
mesh_terms: D000814:Aniline Compounds / Q000737:chemistry*; D001554:Benzene / Q000737:chemistry*; D008956:Models, Chemical; D017550:Spectroscopy, Fourier Transform Infrared; D013059:Spectrum Analysis, Raman; D014050:Toluene / Q000737:chemistry*; D014732:Vibration
chemical_list: D000814:Aniline Compounds; D014050:Toluene; D001554:Benzene; C023650:aniline