title: Molecular conformational analysis, vibrational spectra and normal coordinate analysis of trans-1,2-bis(3,5-dimethoxy phenyl)-ethene based on density functional theory calculations.
abstract: The conformational behavior and structural stability of trans-1,2-bis(3,5-dimethoxy phenyl)-ethene (TDBE) were investigated by using density functional theory (DFT) method with the B3LYP/6-311++G(d,p) basis set combination. The vibrational wavenumbers of TDBE were computed at DFT level and complete vibrational assignments were made on the basis of normal coordinate analysis calculations (NCA). The DFT force field transformed to natural internal coordinates was corrected by a well-established set of scale factors that were found to be transferable to the title compound. The infrared and Raman spectra were also predicted from the calculated intensities. The observed Fourier transform infrared (FTIR) and Fourier transform (FT) Raman vibrational wavenumbers were analyzed and compared with the theoretically predicted vibrational spectra. Comparison of the simulated spectra with the experimental spectra provides important information about the ability of the computational method to describe the vibrational modes. Information about the size, shape, charge density distribution and site of chemical reactivity of the molecules has been obtained by mapping electron density isosurface with electrostatic potential surfaces (ESP).
authors: Department of Physics, Bishop Moore College, Mavelikara, Alappuzha 690110, Kerala, India; Department of Physics, CMS College, Kottayam 686001, Kerala, India.
authors: Lynnette
authors: L
authors: Joseph
authors: Department of Physics, Bishop Moore College, Mavelikara, Alappuzha 690110, Kerala, India. Electronic address: dsajand@gmail.com.
authors: D
authors: D
authors: Sajan
authors: Department of Chemistry, Nanjing University of Science and Technology, Xialingwei 200, Nanjing, People's Republic of China.
authors: K
authors: K
authors: Chaitanya
authors: Department of Physics, CMS College, Kottayam 686001, Kerala, India.
authors: Jayakumary
authors: J
authors: Isac
mesh_terms: D005030:Ethylenes / Q000737:chemistry*; D008958:Models, Molecular; D008968:Molecular Conformation; D011789:Quantum Theory; D017550:Spectroscopy, Fourier Transform Infrared; D013059:Spectrum Analysis, Raman; D055672:Static Electricity; D013696:Temperature; D014732:Vibration
chemical_list: D005030:Ethylenes; C000593951:trans-1,2-bis(3,5-dimethoxy phenyl)-ethene; C036216:ethylene
keywords: Conformational analysis; DFT; ESP; NBO analysis