A dual approach to study the electro-optical properties of a noncentrosymmetric l-asparagine monohydrate

• A new design has been made for growth of LAM single crystals.
• Experimental and theoretical spectroscopy has been studied.
• The grown crystals are highly transparent i.e. ∼80%.
• Theoretically obtained results are found in semi-quantitative agreement with experimental.
• First hyperpolarizability has been found to be 0.883 × 10−30 esu which is twice than urea.

In this work we reports the experimental and theoretical investigation on an organic noncentrosymmetric monohydrated l-asparagine (LAM) molecule. LAM single crystals were grown in specially designed beaker for the first time. Structural confirmation was done by identifying the vibrational modes using IR and FT-Raman spectroscopic studies. The ultra violet–visible–near infrared absorbance, diffuse reflectance spectra were recorded in the spectral range 190–2500 nm. The optical transparency was calculated and found to be ∼80%. Its optical band gap was calculated found to be ∼5.100 eV. Density functional theory (DFT) was employed to optimize the molecular geometry of LAM using B3LYP/6-31G∗ basis set of theory. The HOMO–LUMO energy gap of 6.047 eV and transition energy of 176 nm (f0 = 0.024) have been found in semi-quantitative agreement with our experimental results. The dipole moment, polarizability and first hyperpolarizability were calculated at the same level of theory. The obtained results reveals that the titled compound can be a decent contender for nonlinear applications.

Cut and polished specimens of LAM crystal and its molecular geometry.Figure optionsDownload as PowerPoint slide