Terahertz spectroscopy of dicyanobenzenes: Anomalous absorption intensities and spectral calculations

Esentürk, Okan
Heilweil, E. J.
Terahertz absorption spectra of three isomeric structures of dicyanobenzene in chloroform solution and solid phase at 298 K are reported. These spectra exhibit enhanced absorption in low THz range compared to most organic systems because of strong coupling to phonon modes. Molecular vibrational spectral calculations show strong correlation with the experiment especially for solution spectra. All intramolecular modes were assigned and intermolecular modes identified. Out-of-plane intramolecular modes at low frequency exhibit similar to 75 cm(-1) blue shifts as the secondary CN group moves from the para to ortho position on the benzene ring, whereas almost no frequency shift occurs for low-frequency in-plane modes.


Dielectric Properties of Ethanol and Gasoline Mixtures by Terahertz Spectroscopy and an Effective Method for Determination of Ethanol Content of Gasoline
ARIK, Enis; Altan, Hakan; Esentürk, Okan (American Chemical Society (ACS), 2014-05-01)
Investigation of frequency dependent permittivity of mixture solutions provides information on the role of intermolecular interactions on relaxation processes of solvent and solute molecules. In this study the dielectric properties of ethanol/gasoline mixtures in the terahertz spectral region are investigated. Frequency dependent absorption coefficients, refractive indices, and complex permittivities of pure ethanol and gasoline, and their mixtures at varying ethanol volume percentages (v/v %) are reported....
Valence-shell electron energy-loss spectra of formic acid and acetic acid
Ari, T; Guven, MH (2000-01-01)
Gas phase optical absorption spectra of formic acid and acetic acid in the energy ranges 5.0-11.3 and 4.4-11.3 eV, respectively, have been previously recorded. It is generally agreed that of the four successive bands observed in the spectra of these compounds, the first corresponds to n --> pi* transition. However, various assignments have been proposed for the following three bands. In the present study, electron energy-loss spectra of formic acid and acetic acid vapours at 70 eV impact energy and 0 degree...
AB initio modelling of materials proper ties for catalytic and device applications
Şensoy, Mehmet Gökhan; Toffoli, Hande; Toffoli, Daniele; Department of Physics (2017)
The first-principles computations based on density functional theory is used to study the adsorption properties and the activation of CO, CO2 and H2O on gamma-Al2O3(100) surface. A systematic study has been conducted to identify the most stable adsorption sites for both mono- and di-atomic Pt clusters. Several stable adsorption geometries have been identified for the species as well as introduces their interaction with Pt clusters and the support. In this context, analysis of the adsorption properties allow...
Pyrolysis Studies to Investigate Effects of Polymerization Techniques on Structure and Thermal Behavior of Poly(1,2-Epoxy-4-Epoxyethylcyclohexanes)
Hacaloğlu, Jale; Önal, Ahmet Muhtar (1995-01-01)
Thermal behaviors of poly(1,2-epoxy-4-epoxyethylcyclohexanes) (poly-EECH), polymerized by electroinitiation, radiation, and catalytic action of HClO4 and BF3-etharate, have been studied by direct pyrolysis MS and evolved gas analyses by mass and FT-IR spectrometric techniques. Direct pyrolysis experiments indicated that electroinitiated and catalytic polymerization of EECH with the use of BF3-etharate produced the least stable polymers thermally. High mass peaks were related to the presence of blocks propag...
Radiative Donor-Acceptor Pair Recombination in Tl2Ga2Se3S Layered Single Crystals
Hasanlı, Nızamı (2013-07-01)
The emission band spectra of Tl2Ga2Se3S layered crystals have been studied in the temperature range of 10-50 K and in the wavelength region of 540-700 nm. A broad photoluminescence band centered at 626 nm (1.98 eV) was observed at T = 10 K. Variation of emission band has been studied as a function of excitation laser intensity in the 0.4-51.5 mW cm(-2) range. The analysis of the spectra reveals that the peak energy position changes with laser excitation intensity (blue shift). This behavior of the emission ...
Citation Formats
O. Esentürk and E. J. Heilweil, “Terahertz spectroscopy of dicyanobenzenes: Anomalous absorption intensities and spectral calculations,” CHEMICAL PHYSICS LETTERS, pp. 71–77, 2007, Accessed: 00, 2020. [Online]. Available: https://hdl.handle.net/11511/45852.