Crystal structure and Hirshfeld surface analysis of N-(2-chlorophenylcarbamothioyl)-4-fluorobenzamide and N-(4-bromophenylcarbamothioyl)-4-fluorobenzamide

The title compounds, C14H10ClFN2OS (1) and C14H10BrFN2OS (2), were synthesized by two-step reactions·In the crystal of 1, inversion dimers linked by pairs of N—H⋯S hydrogen bonds generate (8) loops. The extended structure of 2 features the same motif but an additional weak C—H⋯S interaction links the inversion dimers into [100] double columns


Figure 2
The molecular structure of 2 showing 50% displacement ellipsoids; the blue lines represent the intramolecular interactions.

Figure 4
Partial packing diagram for 2.

Synthesis and Crystallization
Compounds 1 and 2 were synthesized by adopting a literature procedure  with slight modification: we refluxed the reactants in distilled solvents for 20 min. instead of refluxing them in anhydrous solvents for 4 h. In the first step, 4-fluorobenzoyle chloride (1 mmol) and potassium thiocyanate (1 mmol) were dissolved in acetone (10 ml) at room temperature with constant stirring for 20 minutes to obtain a white precipitate of 4-fluorophenyl isothiocyanate. In the second step, 1 mmol of 2-chloro phenyl aniline (for 1) or 4bromophenyl aniline (for 2) were added to the mixture and refluxed at 343 K. Hydrochloric acid (0.5 N, 10 ml) was added and the solution was filtered to obtain the desired products: 1 in 69% yield and 2 in 80% yield. For recrystallization, compound 1 was dissolved in a mixture of dichloromethane The Hirshfeld surfaces of 1 and 2.

Figure 6
Two dimensional fingerprint plots for 1.

Figure 7
Two dimensional fingerprint plots for 2. and methanol (1:1) while compound 2 was dissolved in dichloromethane and left for slow evaporation at room temperature to obtain colourless prisms of 1 and colourless plates of 2

Data collection and Refinement
Crystal data, data collection and structure refinement details are summarized in Table 3. The C-bound H atoms atoms were positioned with idealized geometry (C-H = 0.93-0.97 Å ) and refined as riding atoms. In 1, the N-bound H atoms were located in difference-Fourier maps and their positions were freely refined; in 2, the N-bound H atoms were located in difference-Fourier maps and refined as riding atoms in their as-found relative positions. The constraint U iso (H) = 1.2U eq (carrier) was applied in all cases. Table 3 Experimental details. Computer programs: APEX2 and SAINT (Bruker, 2000), SHELXT2014 (Sheldrick, 2015a), SHELXL2016 (Sheldrick, 2015b) and SHELXTL (Sheldrick, 2008). For both structures, data collection: APEX2 (Bruker, 2000); cell refinement: SAINT (Bruker, 2000); data reduction:

N-(2-Chlorophenylcarbamothioyl)-4-fluorobenzamide (1)
Crystal data Special details Geometry. All esds (except the esd in the dihedral angle between two l.s. planes) are estimated using the full covariance matrix. The cell esds are taken into account individually in the estimation of esds in distances, angles and torsion angles; correlations between esds in cell parameters are only used when they are defined by crystal symmetry. An approximate (isotropic) treatment of cell esds is used for estimating esds involving l.s. planes.

N-(4-Bromophenylcarbamothioyl)-4-fluorobenzamide (2)
Crystal data where P = (F o 2 + 2F c 2 )/3 (Δ/σ) max = 0.001 Δρ max = 0.45 e Å −3 Δρ min = −1.46 e Å −3 Special details Geometry. All esds (except the esd in the dihedral angle between two l.s. planes) are estimated using the full covariance matrix. The cell esds are taken into account individually in the estimation of esds in distances, angles and torsion angles; correlations between esds in cell parameters are only used when they are defined by crystal symmetry. An approximate (isotropic) treatment of cell esds is used for estimating esds involving l.s. planes.