Infrared and Raman spectroscopic studies of L-valine L-valinium perchlorate monohydrate

FNR and FT-Raman spectra were recorded and analyzed for L-valine L-valinium perchlorate monohydrate crystals. The wave number assignments have been made for the functional groups, viz. COOH, COO-, -[NH3](+), C-(CH3)(2), C-C-N and C-H. One of the two amino acid residues remains in the zwitterionic form while the other residue exists in the cationic form. The symmetry of the ClO4- anion has been found to be lowered corresponding to ClO2 group. The hydrogen bonds that prevail between amino acid residues, perchlorate anion and water molecule influence the wave numbers of several stretching and deformation modes to deviate from the expected values. (c) 2005 Elsevier B.V. All rights reserved.