Bailey, R. T. and Dines, T. J. and Tedford, M. C. (2011) Electron-phonon coupling in the molecular charge transfer crystal 2-(alpha-methylbenzylamino)-5-nitropyridine. Journal of Molecular Structure, 992 (1-3). pp. 52-58. ISSN 0022-2860Full text not available in this repository. (Request a copy from the Strathclyde author)
Orientated single-crystal infrared, Raman and terahertz measurements have been carried out for the molecular charge transfer material 2-(α-methylbenzylamino)-5-nitropyridine. This information, together with experimental frequency doubling data and theoretical calculations of the electro-optic coefficient, was used to deduce the optical phonon contribution to the linear electro-optic coefficient. The optical phonon spectra are dominated by three intense bands attributed to vibrations of the ring, NO2 substituent and N–H bond. The most intense scattering arose from the αbb component of the polarisability tensor. This implied that the most significant contribution to the transition polarisability arises from the electronic transition near 435 nm, polarised along the b-axis of the crystal. The strongest bands in the infrared spectra are also associated with the same three bands. This implies that efficient electron-phonon coupling (or electronic delocalization) in the conjugated system. DFT calculations of optical phonon frequencies and eigenvectors were used to help assign relevant vibrational features and to derive useful information about the molecular structure. The information obtained from this study is important for assessing the suitability of this material for generating terahertz frequencies by optical rectification.
|Keywords:||Raman, density, single-crystals, electron-phonon coupling, infrared, DFT calculations, MBANP, hydrogen, hyperpolarizability, terahertz, Physical and theoretical chemistry, Organic Chemistry, Spectroscopy, Analytical Chemistry, Inorganic Chemistry|
|Subjects:||Science > Chemistry > Physical and theoretical chemistry|
|Department:||Faculty of Science > Pure and Applied Chemistry|
|Depositing user:||Pure Administrator|
|Date Deposited:||25 Jul 2012 14:02|
|Last modified:||22 Mar 2017 12:14|