Preparation, crystal structure, spectrographic characterization, thermal and third order nonlinear optical properties of benzyltriethylamine bis(2-thioxo-1,3-dithiole-4,5-dithiolato)nickel(III)

The preparation and crystal structure of a novel nonlinear optical organometallic crystal, benzyltriethylamine bis(2-thioxo-1,3-dithiole-4,5-dithiolato)nickel(III) (BTEANDT), are described. The crystal was characterized by elemental analyses, infrared and X-ray powder diffraction spectroscopy, thermal analysis and optical absorption. The third order nonlinear optical properties of crystal were investigated by using the Z-scan technique at 1064 nm with 20 ps. A self-focusing effect and a saturable absorption were observed. The nonlinear refraction coefficient (n2) and the nonlinear absorption coefficient (β) have been found to be 7.311×10−18 m2/W and −6.064×10−11 m/W when the on-axis irradiance at focus (I0) is 3.025 GW/cm2. The relationship between β and I0 was studied, which has revealed that the former is proportional to the latter. The result has been explained with the theory of absorption cross-section.