Synthesis, Crystal Structure, DFT Studies and Antifungal Activity of 5-(4-Cyclopropyl-5-((3-fluorobenzyl)sulfonyl)-4H-1,2,4-triazol-3-yl)-4-methyl-1,2,3-thiadiazole

5-(4-Cyclopropy1-5-((3-fluorobenzypsulfonyl)-4H-1,2,4-triazol-3-yl)-4-methyl-1,2,3-thiadiazole was synthesized and recrystallized from EtOH. The compound was characterized by H-1 NMR, MS, elemental analysis and X-ray diffraction. The structure-active relationship and the antifungal activity based on density functional theory calculation (DFT) and antifungal activities were investigated. The compound crystallizes in the monoclinic space group P121/n1 with a = 8.929(3), b = 12.715(4), c = 15.161(5) angstrom, beta = 106.142(3)degrees, V = 1653.3(9) angstrom(3), Z = 4 and R = 0.0393 for 3930 observed reflections with I > 2 sigma(I). Theoretical calculation of the title compound was carried out with B3LYP/6-31G(d,p). The full geometry optimization was carried out using the 6-31G(d,p) basis set. The frontier orbital energy and atomic net charges were discussed. The observed results of the compound have been compared with theoretical results and the experimental data show good agreement with the calculated values. The compound exhibits good antifungal activity.