Vibrational and structural behavior of L- cysteine ethyl ester.HCl in the solid state and in aqueous solution

M. E. DEFONSI LESTARD; S. B. DÍAZ; M. PUIATTI; G. A. ECHEVERRÍA; O. E. PIRO; A. PIERINI; A. BEN ALTABEF; M. E. TUTTOLOMONDO

JOURNAL OF PHYSICAL CHEMISTRY A

AMER CHEMICAL SOC

Lugar: Washington; Año: 2013 vol. 117 p. 14243 - 14252

1089-5639

The aim of this work is to evaluate the vibrational and structural properties of L-cysteine ethyl ester.HCl (CE), and its electronic behavior mainly in relation to the action of the thiol and amine groups at different degrees of solvation. The crystal structure of CE was determined at room temperature by X-ray diffraction methods. Its Raman, infrared, UV and circular dichroism spectra were measured in aqueous solution. The influence of an aqueous environment on the CE spectra was simulated by means of implicit (polarizable continuum model) and explicit (molecular dynamics, solute-solvent clusters) methods. Calculations in explicit and continuous solvent are of interest to explain the behavior of bioavailable sites in this medium. Infrared and Raman spectra were collected to compare the behavior of different functional groups in the molecule, both in the solid phase and in aqueous solution. The study was completed by natural bond orbital analysis to determine the presence of hyper-conjugative interactions.