Vibrational and structural study of solid state and aqueous solution of L cysteine ethyl ester. HCl

M. E. TUTTOLOMONDO ; S. B. DÍAZ; M. E. DEFONSI LESTARD; C. D. CONTRERAS; O. E. PIRO ; A. BEN ALTABEF

Bangalore

Congreso; 23rd International Conference on Raman Spectroscopy; 2012

The goal of this work was to evaluate the conformation and reactivity of L cysteine ethyl ester. HCl. An experimental study was carried out by Rx measurements and vibrational properties. For the vibrational properties, FTIR and solid state Raman spectra were measured. The structure of this substance was measured by X-Ray diffraction at room temperature (298K). Additionally, quantum mechanical calculations were carried out of its molecular structure which was optimized. The stretching band of the S-H mode may be seen to experience an important displacement towards higher frequencies in the aqueous solution of the Raman spectrum, as compared to the Raman spectrum of the solid. This is due to the molecular interaction of water over Cl- that shortens the S-H bond. In solid state, the H of tiol is found in a weak H bond with Cl-. Hence, the aqueous solution of the tiol site, highly required in biological reactions, would remain open to a possible electrophilic attack.