The crystal and molecular structure of the N-(2-flurobenzoyl)-N'-4-tolylthiourea (FBTT) (C₁₅H₁₃-N₂OFS, M_r=288.34) was determined by X-ray diffraction.The crystal structure is of triclinic, space group: P1, a=0.8413(5) nm, b=0.9532(5) nm, c=0.9927(6) nm, α=66.24(2)°, β=85.40(2)°, γ=72.27(2)°, V=0.6932(7) nm³ and Z=2.The intramolecular hydrogen bonds of N-(2-flurobenzoyl)-N'-4-tolylthiourea were discussed.Minimum energy conformations from DFT (B3LYP) method were calculated as a function of the torsion angle θ[C(13)—N(1)—C(14)—N(2)] varied every 30°.The theoretical calculations are carried out to compare with experimental results of the molecular conformations.The optimized geometry corresponding to crystal structure is the most stable conformation in all theoretical calculations.The energies of hydrogen bonds are estimated.

Key words: benzoylthiourea, crystal structure,DFT, conformation, intramolecular H-bond