Bailey, R. T. and Cruickshank, F. R. and Dines, T. J. and Sherwood, N. and Tedford, A. C. (2011) A single-crystal Raman and infrared study of the nonlinear optical crystal MBANP. Journal of Raman Spectroscopy, 42 (5). pp. 1174-1184. ISSN 0377-0486Full text not available in this repository. (Request a copy from the Strathclyde author)
Single-crystal Raman and polycrystalline thin-film infrared measurements have been obtained for the polar organic nonlinear optical material 2-(alpha-methylbenzylamino)-5-nitropyridine(MBANP). For comparison, thin-film polycrystalline infrared measurements were also made on 2-(alpha-methylbenzylamino)-3,5-dinitropyridine (MBADNP). The long wavelength electronic absorption was measured in several solvents and as a thin solid film. The Raman spectra are dominated by three intense bands attributed to vibrations of the ring, the NO(2) substituent, and the N-H bond. The most intense scattering and absorption arose from the alpha(bb) component of the polarisability tensor. This implies that the most significant contribution to the transition polarisability arises from the electronic transition near 383 nm, polarised along the b-axis of the crystal. The strongest bands in the infrared spectra are also associated with the same three bands, consistent with the predictions of the effective conjugation coordinate (ECC) theory, implying efficient electron-phonon coupling (or electronic delocalisation) in the conjugated system. DFT calculations of vibrational wavenumbers and eigenvectors were used to assign relevant vibrational features and to derive useful information about the molecular structure. This single-crystal material is also a strong candidate for an efficient laser Raman converter with a large wavenumber shift of 3404 cm(-1) and a high damage threshold.
|Keywords:||atoms, dft calculations, electron-phonon coupling, exchange, raman spectroscopy, organic nonlinear, thermal-properties, density, derivatives, molecules, mbanp, hydrogen, vibrational-spectra, single-crystal raman, infrared study, nonlinear optical crystal, study, Chemistry, Spectroscopy, Materials Science(all)|
|Subjects:||Science > Chemistry|
|Department:||Faculty of Science > Pure and Applied Chemistry|
|Depositing user:||Pure Administrator|
|Date Deposited:||03 Aug 2012 12:54|
|Last modified:||27 Apr 2016 18:53|