The structure and conformation analysis of N-2-fluorobenzoyl-N′-2-methoxyphenylthiourea

The structure of the N-2-fluorobenzoyl-N′-2-methoxyphenyl thiourea (C15H13FN2O2S, Mr=304.34) derived from X-ray diffraction on single crystal has been presented. The crystal is triclinic, space group: P−1 (#2), a=7.058(4), b=9.067(5), c=11.907(8) Å, α=89.00(2), β=86.59(2), γ=69.02(1)°, V=710.2(8) Å3, Z=2. FTIR, NMR and X-ray diffraction determination give the existence of hydrogen bond interactions. Density functional theory (DFT) using Becke's three-parameter hybrid method with the Lee, Yang, and Parr correlation functional (B3LYP) methods have been used to determine the structure and energies of stable conformers. The optimized geometry corresponding to crystal structure is the most stable conformation. This has partly been attributed to multi six-tempered and five-tempered ring formation resulting from the N(2)-H(2)⋯(1), N-(1) H(1)⋯F(1), N(2)-H(2)⋯O(2) and C(6)-H(6)⋯O(2) intra-molecular hydrogen bonds, respectively. With the basis sets of the 6-311G** quality, the DFT calculated bond parameters, harmonic vibrations and nuclear magnetic resonance values are in a very good agreement with experimental results.