l-lysine monohydrochloride dihydrate as novel elasto- and electrooptical materials

We have studied optical parametrical effects (electrooptical and elastooptical ones) at wavelength 1150 nm generated by continuous He-Ne laser. We have found that the maximal value of the effective electrooptics coefficient is equal to about 12.6 pm/V and of the elastooptical coefficient was 12 · 1014 m2/N and was achieved at temperature about 300 K. l-lysine monohydrochloride dihydrate (C6H14N2O2, HCl·2H2O, LLMHCl), a semiorganic potential nonlinear optically active crystal belongs to noncentrosymmetry class P21. FTIR and FT Raman of this crystal have been studied at room temperature. The vibrational spectral characterization has been carried out for different Raman configurations and has been interpreted following existed crystal structural data and factor group analysis. Following the performed analysis it was discovered that the principal role in the observed electrooptics group plays the vibrational bands originating of the functional groups such as [NH3]+, C=O, O-H, C-H, C-N, O-C=O, C-N-C-C ring, C-OH. For elastooptical effects the principal role belongs to the modes situated at 3500-1500 cm− 1 originating from stretching vibrations of [NH3]+, CH2, C=O, COO− and C-N groups.