Eur. Phys. J. Plus (2016) 131: 375
https://doi.org/10.1140/epjp/i2016-16375-0

Regular Article

Synthesis, growth, optical and anisotropic mechanical behaviour of organic nonlinear optical imidazolium 2-chloro-4-nitrobenzoate single crystals

Department of Physics, Periyar University, Salem-636011, Tamil Nadu, India

^* e-mail: vkrishna_kumar@yahoo.com

Received: 27 June 2016
Accepted: 23 September 2016
Published online: 25 October 2016

Abstract

The title compound, imidazolium 2-chloro-4-nitrobenzoate (I2C4NB), has been synthesized and optical quality single crystals were grown with a dimension of mm³ using an ethanol and acetone (1:1) mixed solvent by slow evaporation solution growth technique. The powder XRD analysis confirmed the crystal structure and found that it is crystallized in the non-centrosymmetric space group P2₁ with the monoclinic system. The symmetries of molecular vibrations were confirmed by FT-IR spectrum. The CHN(S) analysis confirmed the stoichiometric composition of the grown crystal. It also exhibits a good transparency in the entire visible region (300-800nm) and it was thermally stable up to 131.1 ^°C. The microhardness measurement shows the anisotropic nature of I2C4NB and also that it belongs to a soft material category. Photoconductivity studies reveal a linear increase of the photocurrent with respect to the applied electric field. HOMO LUMO studies were carried out for the crystal. The second harmonic generation test by the Kurtz powder method shows that the crystal exhibits phase matching and a conversion efficiency which is 2 times that of KDP.