Raman scattering studies of monohydrated L-asparagine

Abstract

Polarized rst-order Raman scattering studies at 300 K were carried out in L -asparagine monohydrate crystal in order to obtain the general assignment of its phonon spectra. A careful analysis of the vibrational spectra shows that the assignment of the fundamental vibrational modes can be done on the basis of amino, carboxilic and water groups vibrations, and correlations with previous data reported for other amino acids. However, some vibrations were correctly assigned from the study of its temperature -dependence behavior performed in the range 10 -300 K. The assignment proposed con rm the zwitterionic structure of L-asparagine monohydrate crystal.

Raman study of L-Asparagine and L-Glutamine molecules adsorbed on aluminum films in a wide frequency range

“…The mode at 131 cm -1 in Asparagine as well as modes at 125 and 135 cm -1 in Glutamine can be assigned to molecular associated vibrations in amino acid in the solid state [3]. These bands belong to Bsymmetry modes and should be both Raman and IR active [7]. The medium intensity Raman band of L-Gln located at about 185 cm and stretching vibrations of the CO 2 and C=O groups, symmetric and antisymmetric vibrations of molecular backbone and side-groups.…”

“…3 and enlisted in Table 1 include the bands attributed to lattice vibrations and molecular vibrations involving the COO -torsion, NH 3 torsion and CC α N deformation ones [6][7][8][9][14][15][16]. They are specific for each type of molecules.…”

“…Vibrational frequencies obtained from the measured micro-Raman spectra and proposed assignments for the observed bands are summarized in Table 2. Most assignments are based on the works [3,7], while other sources were usually indicated in text.…”

“…Implementation of Raman spectroscopy for the solid Glutamine analysis was investigated only in few previous studies [3,5,6]. А detailed Raman study of Asparagine monohydrate crystal was carried out by Moreno et al in [7,8]. By use of IR, Raman, inelastic neutron scattering measurements and DFT calculation, the normal modes of vibrational spectra of pure L-glutamine in the solid state were determined and described [9].…”

Vibrational and thermal properties of crystalline topiramate

“…Modes with wavenumber lower than 150 cm -1 are generally assigned as lattice modes. 9 The tentative assignments of bands observed in the Raman and in the IR spectra of topiramate, based on published vibrational studies on other sulfamates [10][11][12][13][14][15][16][17] and studies on other correlated materials, [18][19][20][21][22][23] as well as DFT calculations, are given in Table 2. In each case, the most intense band was given a value of 100, and relative intensities are shown in parentheses.…”