Synthesis, growth, structural modeling and physio-chemical properties of a charge transfer molecule: Guanidinium tosylate. (May 2018)

• Record Type: Journal Article
• Authors: Era, Paavai; Jauhar, RO. MU.; Vinitha, G.; Murugakoothan, P.
• Is Part Of: Optics & laser technology. Volume 101(2018)
• Page Start: 127
• Page End: 137
• Publication Date: 2018-05
• Subjects: A1. Bulk crystal -- A2. Optical transmittance -- B1. Z-scan -- B2. Anisotropic behavior; Optics -- Periodicals; Lasers -- Periodicals; Electronic journals; 621.366
• DOI: 10.1016/j.optlastec.2017.11.005
• Languages: English
• ISSNs: 0030-3992

Abstract

Highlights: Bulk crystal of GT has been grown by slow evaporation technique. Anisotropy in the mechanical behavior was observed while measuring for individual planes. Third order nonlinear optical properties have been reported. Optical limiting behavior of GT crystal was found to be 0.23 mW/cm 2 . Abstract: An organic nonlinear optical material, guanidinium tosylate was synthesized adopting slow evaporation method and the crystals were harvested from aqueous methanolic medium with dimensions 13 × 9 × 3 mm 3 . Constitution of crystalline material was confirmed by single crystal X-ray diffraction study. The title compound crystallizes in the monoclinic crystal system with space group P 21 / c . The UV–vis–NIR spectral study of the grown crystal exhibits high transparency of 80% in the entire visible region with lower cut-off wavelength at 282 nm. Optimized molecular geometry of the grown crystal was obtained using density functional theory (DFT) and the frontier energy gaps calculated from the DFT aids to understand the charge transfer taking place in the molecule. The dielectric properties were studied as a function of temperature and frequency to find the charge distribution within the crystal. The titular compound is thermally stable up to 230 °C assessed by thermogravimetric and differential thermal analysis. Anisotropy in the mechanical behavior was observed while measuring for individual planes. The laser induced surface damage threshold of the grown crystal was measured to be 0.344 GW/cm 2 for 1064 nm Nd:YAG laser radiation. Z-scan technique confirms the third-order nonlinear optical property with the ascertained nonlinear refractive index (n2 ), nonlinear absorption coefficient (β) and third order nonlinear susceptibility (χ (3) ). Optical limiting study divulges that the transmitted output power step-up linearly with the increase of the input power at lower power realms and saturates from the threshold 24.95 mW/cm 2 and amplitude 0.23 mW/cm 2 .