Growth, Structure And Properties Of Benzothiazole Crystalline DOBT And Its Derivative

Benzothiazolium organic second-order NLO crystals have important application potential in the field of terahertz(THz)generation and detection due to their excellent second-order nonlinear optical properties and other advantages.In this paper,on the basis of DAST crystals,a novel benzothiazolium organic nonlinear optical crystal2-(3,4-dimethoxystyryl)-3-methylbenzothiazolium-4-methylbenzenesulfonate(DOBT)was synthesized by introducing a benzothiazolium ring with stronger electron withdrawing ability,and the growth of bulk single crystal by slow cooling method.Single crystal X-ray diffraction was used to determine the composition and structure of the crystal.Through the analysis of the corrosion morphology of the crystal surface,the crystal growth mechanism was explored.Through the HOMO-LUMO orbital analysis,surface electrostatic potential analysis and Hieshfelef surface analysis of the crystal,it is clear that there are various forces and charge transfer within the crystal molecules and on the surface.The PL spectrum,UV-Vis-NIR spectrum,dielectric properties and thermal stability of the crystal were analyzed.Based on the structure of DOBT and without changing the structure of D-π-A,a new benzothiazolium organic second-order nonlinear optical crystal DOBS was synthesized by changing the anionic functional group.The molecular structure and arrangement of the crystal were determined by single crystal XRD diffraction experiment,and analyzed and compared with the DOBT crystal.Measureed and calculated molecular surface electrostatic potential,molecular orbital energy gap,and drawed Hirshfeld surface analysis diagram,so as to analyze various forces and interactions existing in crystals.The second harmonic generation efficiency of DOBS crystal was tested and analyzed.At the same time,the optical,thermal and electrical properties of the crystal were tested,and compared with those of DOBT crystal.