Structural, DFT and nonlinear optical studies of hemihydrate thiadiazole derivative

A new organic nonlinear optical material 7-(4-bromobenzyl)-3-(tert-butyl)-4H-[1,3,4]thiadiazolo[2,3-c][1,2,4]triazin-4-onehemihydrate (TDTZ) single crystal was grown by slow evaporation solution technique. The lattice parameters of the grown crystal were elucidated by single crystal X-ray diffraction method. The crystal structure revealed the crystallization of the compound in the monoclinic system withthe C2/c space group. UV-Vis NIR spectrum analysis deciphered TDTZ’s optical transmittance, cutoff wavelength, and bandgap. Hirshfeld surface studies were performed to understand the intermolecular interactions of the title compound. The density functional theory (DFT) using B3LYP functional with 6-311G (d,p) basis set was carried out forFrontier Molecular Orbital (FMO) analysis to estimate the transition barrier and chemical reactivity. Nonlinear optical activity wasdetermined from TDHF methods with 6-31G(d) basis sets using the GAMESS program.