title: Synthesis, characterization and quantum chemical investigation of molecular structure and vibrational spectra of 2,5-dichloro-3,6-bis-(methylamino)1,4-benzoquinone.
abstract: 2,5-Dichloro-3,6-bis-methylamino-[1,4]benzoquinone has been synthesized by condensing methyl amine hydrochloride with chloranil in presence of condensing agent sodium acetate. FT-IR (4000-400 cm(-1)) and FT-Raman (4000-400 cm(-1)) spectral measurements of dmdb have been done. Ab initio and DFT (B3LYP/6-311+G(**)) calculations have been performed giving energies, optimized structures, harmonic vibrational frequencies, infrared intensities and Raman activities. The optimized molecular structure of the compound is found to possess C2h point group symmetry. A detailed interpretation of the observed IR and Raman spectra of dmdb is reported on the basis of the calculated potential energy distribution. Stability of the molecule arising from hyper conjugative interactions, charge delocalization has been analyzed using NBO analysis. The HOMO and LUMO energy gap reveals that the energy gap reflects the chemical activity of the molecule. The thermodynamic functions of the title compound have also been computed.
authors.affiliation: Department of Chemistry, Banaras Hindu University, Varanasi 221005, India.
authors.forename: Bhanu Pratap Singh
authors.initials: BP
authors.lastname: Gautam
authors.affiliation: Department of Physics, Banaras Hindu University, Varanasi 221005, India.
authors.forename: Mayuri
authors.initials: M
authors.lastname: Srivastava
authors.affiliation: Department of Chemistry, Banaras Hindu University, Varanasi 221005, India.
authors.forename: R L
authors.initials: RL
authors.lastname: Prasad
authors.affiliation: Department of Physics, Banaras Hindu University, Varanasi 221005, India. Electronic address: rayadav@bhu.ac.in.
authors.forename: R A
authors.initials: RA
authors.lastname: Yadav
mesh_terms: D000586:Amination; D016227:Benzoquinones / Q000737:chemistry*; D054879:Halogenation; D008745:Methylation; D008958:Models, Molecular; D017550:Spectroscopy, Fourier Transform Infrared; D013059:Spectrum Analysis, Raman
chemical_list: D016227:Benzoquinones; C004532:quinone
keywords: Ab initio calculations; DFT calculation; MESP; NBO analysis; Optimized geometry; Quinones