In the title compound, C
8H
8N
2OS, strong intramolecular N—H
O hydrogen bonds [N
O = 2.669 (3) and 2.618 (3) Å] form almost planar six-membered rings and enforce the conformation of the molecule. Two kinds of intermolecular N—H
S hydrogen bonds [N
S = 3.309 (3)–3.456 (2) Å] between two symmetry-independent molecules form consecutive dimers that expand in ribbons along the [100] direction.
Supporting information
CCDC reference: 205313
N-benzoylthiourea was prepared by a modification of the method previously described by Klayman et al. (1972). Benzoyl chloride was added to a solution of potassium thiocyanate in warm anhydrous acetone, and the resulting mixture was refluxed. Potassium chloride, which precipitated as a fine powder, was removed by filtration and a concentrated aqueous ammonia solution was added to the filtrate. The resulting mixture was evaporated to dryness using a rotatory evaporator and the residue was extracted with ethanol. Colourless crystals of (I) were obtained by slow evaporation from a methanol solution.
Data collection: KM-4 Software (Kuma Diffraction, 1992); cell refinement: KM-4 Software; data reduction: KM-4 Software; program(s) used to solve structure: SHELXS97 (Sheldrick, 1990); program(s) used to refine structure: SHELXL97 (Sheldrick, 1997); molecular graphics: Stereochemical Workstation Operation Manual (Siemens, 1989).
Crystal data top
C8H8N2OS | Z = 4 |
Mr = 180.22 | F(000) = 376 |
Triclinic, P1 | Dx = 1.365 Mg m−3 |
Hall symbol: -p-1 | Mo Kα radiation, λ = 0.71073 Å |
a = 8.2300 (16) Å | Cell parameters from 25 reflections |
b = 9.3410 (18) Å | θ = 5–26° |
c = 12.594 (3) Å | µ = 0.32 mm−1 |
α = 73.91 (3)° | T = 293 K |
β = 88.14 (3)° | Plate, colourless |
γ = 70.80 (3)° | 0.30 × 0.15 × 0.10 mm |
V = 876.7 (4) Å3 | |
Data collection top
Kuma KM-4 four-circle diffractometer | Rint = 0.025 |
Radiation source: fine-focus sealed tube | θmax = 25.1°, θmin = 2.5° |
Graphite monochromator | h = −9→9 |
ω/2θ scans | k = 0→10 |
3276 measured reflections | l = −14→14 |
3067 independent reflections | 3 standard reflections every 100 reflections |
1929 reflections with I > 2σ(I) | intensity decay: 3% |
Refinement top
Refinement on F2 | Secondary atom site location: difference Fourier map |
Least-squares matrix: full | Hydrogen site location: inferred from neighbouring sites |
R[F2 > 2σ(F2)] = 0.034 | All H-atom parameters refined |
wR(F2) = 0.071 | w = 1/[σ2(Fo2) + (0.01P)2 + 0.3P] where P = (Fo2 + 2Fc2)/3 |
S = 1.00 | (Δ/σ)max = 0.009 |
3067 reflections | Δρmax = 0.15 e Å−3 |
282 parameters | Δρmin = −0.21 e Å−3 |
0 restraints | Extinction correction: SHELXL97 (Sheldrick, 1997), Fc*=kFc[1+0.001xFc2λ3/sin(2θ)]-1/4 |
Primary atom site location: structure-invariant direct methods | Extinction coefficient: 0.024 (2) |
Crystal data top
C8H8N2OS | γ = 70.80 (3)° |
Mr = 180.22 | V = 876.7 (4) Å3 |
Triclinic, P1 | Z = 4 |
a = 8.2300 (16) Å | Mo Kα radiation |
b = 9.3410 (18) Å | µ = 0.32 mm−1 |
c = 12.594 (3) Å | T = 293 K |
α = 73.91 (3)° | 0.30 × 0.15 × 0.10 mm |
β = 88.14 (3)° | |
Data collection top
Kuma KM-4 four-circle diffractometer | Rint = 0.025 |
3276 measured reflections | 3 standard reflections every 100 reflections |
3067 independent reflections | intensity decay: 3% |
1929 reflections with I > 2σ(I) | |
Refinement top
R[F2 > 2σ(F2)] = 0.034 | 0 restraints |
wR(F2) = 0.071 | All H-atom parameters refined |
S = 1.00 | Δρmax = 0.15 e Å−3 |
3067 reflections | Δρmin = −0.21 e Å−3 |
282 parameters | |
Special details top
Geometry. All e.s.d.'s (except the e.s.d. in the dihedral angle between two l.s. planes) are estimated using the full covariance matrix. The cell e.s.d.'s are taken into account individually in the estimation of e.s.d.'s in distances, angles and torsion angles; correlations between e.s.d.'s in cell parameters are only used when they are defined by crystal symmetry. An approximate (isotropic) treatment of cell e.s.d.'s is used for estimating e.s.d.'s involving l.s. planes. |
Refinement. Refinement of F2 against ALL reflections. The weighted R-factor wR and goodness of fit S are based on F2, conventional R-factors R are based on F, with F set to zero for negative F2. The threshold expression of F2 > σ(F2) is used only for calculating R-factors(gt) etc. and is not relevant to the choice of reflections for refinement. R-factors based on F2 are statistically about twice as large as those based on F, and R- factors based on ALL data will be even larger. |
Fractional atomic coordinates and isotropic or equivalent isotropic displacement parameters (Å2) top | x | y | z | Uiso*/Ueq | |
C1A | 0.7198 (3) | 0.8666 (3) | 0.79040 (16) | 0.0461 (5) | |
C2A | 0.7341 (4) | 0.9887 (3) | 0.8263 (2) | 0.0648 (7) | |
H2A | 0.643 (4) | 1.084 (3) | 0.814 (2) | 0.096 (10)* | |
C3A | 0.8884 (4) | 0.9755 (4) | 0.8743 (2) | 0.0774 (8) | |
H3A | 0.901 (3) | 1.057 (3) | 0.895 (2) | 0.083 (9)* | |
C4A | 1.0266 (4) | 0.8403 (4) | 0.8887 (2) | 0.0782 (9) | |
H4A | 1.130 (4) | 0.834 (3) | 0.928 (2) | 0.094 (9)* | |
C5A | 1.0118 (4) | 0.7171 (4) | 0.8566 (2) | 0.0792 (9) | |
H5A | 1.100 (3) | 0.623 (3) | 0.8720 (19) | 0.076 (8)* | |
C6A | 0.8586 (3) | 0.7293 (3) | 0.80687 (19) | 0.0614 (7) | |
H6A | 0.847 (3) | 0.649 (3) | 0.7871 (18) | 0.065 (8)* | |
C11A | 0.5498 (3) | 0.8855 (3) | 0.74004 (17) | 0.0484 (5) | |
O11A | 0.4140 (2) | 0.9440 (2) | 0.77829 (13) | 0.0666 (5) | |
N11A | 0.5567 (2) | 0.8304 (2) | 0.64877 (15) | 0.0463 (5) | |
H11A | 0.646 (3) | 0.813 (2) | 0.6214 (16) | 0.038 (6)* | |
C12A | 0.4222 (3) | 0.8226 (2) | 0.59098 (16) | 0.0456 (5) | |
S12A | 0.46386 (8) | 0.75591 (9) | 0.47884 (5) | 0.0619 (2) | |
S12B | 0.95337 (7) | 0.73710 (9) | 0.54810 (5) | 0.0612 (2) | |
N12A | 0.2691 (3) | 0.8617 (3) | 0.62850 (19) | 0.0597 (6) | |
H121 | 0.258 (3) | 0.894 (3) | 0.6792 (18) | 0.053 (8)* | |
H122 | 0.180 (4) | 0.843 (3) | 0.598 (2) | 0.087 (9)* | |
C1B | 0.7081 (3) | 0.6561 (3) | 0.21436 (17) | 0.0461 (5) | |
C2B | 0.6660 (3) | 0.7133 (3) | 0.10126 (19) | 0.0634 (7) | |
H2B | 0.730 (3) | 0.772 (3) | 0.0563 (19) | 0.077 (8)* | |
C3B | 0.5285 (4) | 0.6890 (4) | 0.0574 (2) | 0.0719 (8) | |
H3B | 0.498 (3) | 0.732 (3) | −0.016 (2) | 0.077 (8)* | |
C4B | 0.4341 (3) | 0.6103 (3) | 0.1238 (2) | 0.0654 (7) | |
H4B | 0.339 (3) | 0.595 (3) | 0.094 (2) | 0.083 (8)* | |
C5B | 0.4767 (3) | 0.5513 (3) | 0.2361 (2) | 0.0558 (6) | |
H5B | 0.417 (3) | 0.496 (3) | 0.2832 (18) | 0.064 (7)* | |
C6B | 0.6134 (3) | 0.5743 (3) | 0.28104 (19) | 0.0483 (6) | |
H6B | 0.639 (3) | 0.534 (2) | 0.3554 (17) | 0.054 (6)* | |
C11B | 0.8600 (3) | 0.6803 (3) | 0.25664 (18) | 0.0521 (6) | |
O11B | 0.9836 (2) | 0.6829 (3) | 0.20079 (13) | 0.0811 (6) | |
N11B | 0.8552 (2) | 0.7006 (2) | 0.36139 (14) | 0.0473 (5) | |
H11B | 0.760 (2) | 0.700 (2) | 0.3895 (15) | 0.036 (5)* | |
C12B | 0.9821 (3) | 0.7191 (3) | 0.41926 (17) | 0.0504 (6) | |
N12B | 1.1223 (3) | 0.7217 (4) | 0.3704 (2) | 0.0963 (10) | |
H123 | 1.205 (3) | 0.723 (3) | 0.405 (2) | 0.082 (9)* | |
H124 | 1.127 (4) | 0.706 (3) | 0.308 (2) | 0.095 (10)* | |
Atomic displacement parameters (Å2) top | U11 | U22 | U33 | U12 | U13 | U23 |
C1A | 0.0489 (13) | 0.0522 (14) | 0.0391 (11) | −0.0170 (11) | 0.0017 (9) | −0.0158 (10) |
C2A | 0.0671 (18) | 0.0581 (17) | 0.0679 (16) | −0.0155 (15) | −0.0178 (13) | −0.0198 (14) |
C3A | 0.087 (2) | 0.078 (2) | 0.0769 (19) | −0.0354 (19) | −0.0205 (15) | −0.0250 (16) |
C4A | 0.0593 (18) | 0.116 (3) | 0.0621 (17) | −0.0257 (19) | −0.0109 (13) | −0.0328 (17) |
C5A | 0.0577 (18) | 0.100 (2) | 0.0688 (18) | 0.0055 (17) | −0.0132 (14) | −0.0423 (18) |
C6A | 0.0634 (16) | 0.0638 (18) | 0.0548 (15) | −0.0070 (14) | −0.0070 (12) | −0.0291 (13) |
C11A | 0.0514 (14) | 0.0481 (14) | 0.0472 (13) | −0.0170 (11) | 0.0008 (10) | −0.0149 (11) |
O11A | 0.0513 (10) | 0.0865 (13) | 0.0694 (11) | −0.0167 (9) | 0.0060 (8) | −0.0414 (10) |
N11A | 0.0410 (11) | 0.0580 (13) | 0.0478 (11) | −0.0210 (10) | 0.0038 (9) | −0.0221 (9) |
C12A | 0.0438 (13) | 0.0469 (14) | 0.0456 (12) | −0.0186 (11) | −0.0003 (10) | −0.0079 (10) |
S12A | 0.0506 (4) | 0.1030 (6) | 0.0498 (4) | −0.0390 (4) | 0.0057 (3) | −0.0332 (4) |
S12B | 0.0452 (4) | 0.0976 (5) | 0.0504 (4) | −0.0282 (3) | 0.0009 (3) | −0.0307 (3) |
N12A | 0.0433 (13) | 0.0795 (16) | 0.0637 (14) | −0.0184 (11) | 0.0015 (11) | −0.0341 (13) |
C1B | 0.0442 (12) | 0.0514 (14) | 0.0446 (12) | −0.0129 (11) | 0.0013 (10) | −0.0201 (11) |
C2B | 0.0644 (16) | 0.089 (2) | 0.0448 (13) | −0.0339 (15) | 0.0059 (12) | −0.0214 (13) |
C3B | 0.0717 (18) | 0.105 (2) | 0.0434 (15) | −0.0340 (17) | −0.0079 (13) | −0.0211 (15) |
C4B | 0.0605 (17) | 0.0751 (19) | 0.0693 (18) | −0.0247 (15) | −0.0120 (14) | −0.0295 (15) |
C5B | 0.0579 (15) | 0.0496 (15) | 0.0632 (16) | −0.0222 (13) | −0.0021 (12) | −0.0152 (13) |
C6B | 0.0515 (14) | 0.0466 (14) | 0.0465 (13) | −0.0136 (11) | −0.0032 (11) | −0.0152 (11) |
C11B | 0.0475 (13) | 0.0654 (16) | 0.0487 (13) | −0.0207 (12) | 0.0034 (11) | −0.0219 (12) |
O11B | 0.0612 (11) | 0.1485 (18) | 0.0625 (11) | −0.0562 (12) | 0.0212 (9) | −0.0515 (11) |
N11B | 0.0353 (10) | 0.0659 (13) | 0.0459 (11) | −0.0186 (9) | 0.0042 (8) | −0.0220 (9) |
C12B | 0.0386 (13) | 0.0667 (16) | 0.0487 (13) | −0.0191 (11) | 0.0004 (10) | −0.0187 (12) |
N12B | 0.0617 (16) | 0.200 (3) | 0.0664 (16) | −0.0758 (18) | 0.0179 (13) | −0.0619 (19) |
Geometric parameters (Å, º) top
S12A—C12A | 1.678 (2) | C5A—H5A | 0.91 (2) |
O11A—C11A | 1.220 (2) | C6A—H6A | 0.89 (2) |
N11A—C11A | 1.376 (3) | N11A—H11A | 0.791 (19) |
N11A—C12A | 1.377 (3) | N12A—H121 | 0.77 (2) |
N12A—C12A | 1.303 (3) | N12A—H122 | 0.93 (3) |
S12B—C12B | 1.679 (2) | C1B—C6B | 1.375 (3) |
O11B—C11B | 1.220 (3) | C1B—C2B | 1.387 (3) |
N11B—C11B | 1.382 (3) | C1B—C11B | 1.481 (3) |
N11B—C12B | 1.374 (3) | C2B—C3B | 1.384 (3) |
N12B—C12B | 1.295 (3) | C2B—H2B | 0.95 (2) |
C1A—C6A | 1.377 (3) | C3B—C4B | 1.356 (4) |
C1A—C2A | 1.378 (3) | C3B—H3B | 0.91 (2) |
C1A—C11A | 1.491 (3) | C4B—C5B | 1.379 (3) |
C2A—C3A | 1.377 (4) | C4B—H4B | 0.95 (3) |
C2A—H2A | 0.94 (3) | C5B—C6B | 1.378 (3) |
C3A—C4A | 1.365 (4) | C5B—H5B | 0.92 (2) |
C3A—H3A | 0.90 (3) | C6B—H6B | 0.91 (2) |
C4A—C5A | 1.362 (4) | N11B—H11B | 0.850 (19) |
C4A—H4A | 0.98 (3) | N12B—H123 | 0.83 (3) |
C5A—C6A | 1.383 (4) | N12B—H124 | 0.84 (3) |
| | | |
S12A—C12A—N11A | 118.70 (17) | C12A—N11A—H11A | 116.0 (15) |
S12A—C12A—N12A | 122.97 (18) | C12A—N12A—H121 | 118.0 (17) |
N11A—C12A—N12A | 118.3 (2) | C12A—N12A—H122 | 120.2 (16) |
C11A—N11A—C12A | 128.0 (2) | H121—N12A—H122 | 122 (2) |
S12B—C12B—N11B | 120.50 (16) | C6B—C1B—C2B | 119.2 (2) |
S12B—C12B—N12B | 122.19 (18) | C6B—C1B—C11B | 123.09 (19) |
N11B—C12B—N12B | 117.3 (2) | C2B—C1B—C11B | 117.6 (2) |
C11B—N11B—C12B | 127.72 (19) | C3B—C2B—C1B | 119.8 (3) |
C6A—C1A—C2A | 119.5 (2) | C3B—C2B—H2B | 121.7 (15) |
C6A—C1A—C11A | 122.3 (2) | C1B—C2B—H2B | 118.5 (15) |
C2A—C1A—C11A | 118.2 (2) | C4B—C3B—C2B | 120.7 (2) |
C3A—C2A—C1A | 120.0 (3) | C4B—C3B—H3B | 119.9 (16) |
C3A—C2A—H2A | 118.8 (17) | C2B—C3B—H3B | 119.3 (16) |
C1A—C2A—H2A | 121.0 (17) | C3B—C4B—C5B | 119.8 (2) |
C4A—C3A—C2A | 120.3 (3) | C3B—C4B—H4B | 120.5 (15) |
C4A—C3A—H3A | 118.9 (17) | C5B—C4B—H4B | 119.7 (15) |
C2A—C3A—H3A | 120.8 (17) | C6B—C5B—C4B | 120.1 (3) |
C3A—C4A—C5A | 120.0 (3) | C6B—C5B—H5B | 117.9 (14) |
C3A—C4A—H4A | 116.8 (16) | C4B—C5B—H5B | 122.0 (14) |
C5A—C4A—H4A | 123.0 (16) | C1B—C6B—C5B | 120.4 (2) |
C4A—C5A—C6A | 120.4 (3) | C1B—C6B—H6B | 121.1 (13) |
C4A—C5A—H5A | 120.7 (16) | C5B—C6B—H6B | 118.6 (13) |
C6A—C5A—H5A | 118.7 (16) | O11B—C11B—N11B | 121.6 (2) |
C1A—C6A—C5A | 119.7 (3) | O11B—C11B—C1B | 121.20 (19) |
C1A—C6A—H6A | 119.1 (15) | N11B—C11B—C1B | 117.18 (19) |
C5A—C6A—H6A | 121.2 (15) | C12B—N11B—H11B | 120.7 (13) |
O11A—C11A—N11A | 122.4 (2) | C11B—N11B—H11B | 111.5 (13) |
O11A—C11A—C1A | 122.10 (19) | C12B—N12B—H123 | 119.5 (18) |
N11A—C11A—C1A | 115.54 (19) | C12B—N12B—H124 | 115 (2) |
C11A—N11A—H11A | 115.4 (15) | H123—N12B—H124 | 124 (3) |
| | | |
C6A—C1A—C11A—O11A | 135.1 (2) | C11B—C1B—C2B—C3B | 177.9 (2) |
C6B—C1B—C11B—O11B | 145.3 (2) | C1B—C2B—C3B—C4B | 0.2 (4) |
C6A—C1A—C2A—C3A | 2.6 (4) | C2B—C3B—C4B—C5B | −1.0 (4) |
C11A—C1A—C2A—C3A | 179.4 (2) | C3B—C4B—C5B—C6B | 0.9 (4) |
C1A—C2A—C3A—C4A | −1.5 (4) | C2B—C1B—C6B—C5B | −0.9 (3) |
C2A—C3A—C4A—C5A | −0.6 (5) | C11B—C1B—C6B—C5B | −177.8 (2) |
C3A—C4A—C5A—C6A | 1.6 (5) | C4B—C5B—C6B—C1B | 0.0 (4) |
C2A—C1A—C6A—C5A | −1.7 (4) | C2B—C1B—C11B—O11B | −31.7 (4) |
C11A—C1A—C6A—C5A | −178.3 (2) | C6B—C1B—C11B—N11B | −35.1 (3) |
C4A—C5A—C6A—C1A | −0.4 (4) | C2B—C1B—C11B—N11B | 147.9 (2) |
C2A—C1A—C11A—O11A | −41.6 (3) | O11B—C11B—N11B—C12B | −2.9 (4) |
C6A—C1A—C11A—N11A | −43.9 (3) | C1B—C11B—N11B—C12B | 177.4 (2) |
C2A—C1A—C11A—N11A | 139.4 (2) | C11B—N11B—C12B—N12B | 1.8 (4) |
O11A—C11A—N11A—C12A | −4.0 (4) | C11B—N11B—C12B—S12B | −178.20 (19) |
C1A—C11A—N11A—C12A | 175.1 (2) | O11A—C11A—C12A—S12A | 173.4 (2) |
C11A—N11A—C12A—N12A | −4.7 (3) | O11A—C11A—C12A—N12A | −7.5 (2) |
C11A—N11A—C12A—S12A | 177.85 (18) | O11B—C11B—C12B—S12B | −179.7 (2) |
C6B—C1B—C2B—C3B | 0.8 (4) | O11B—C11B—C12B—N12B | −0.9 (2) |
Hydrogen-bond geometry (Å, º) top
D—H···A | D—H | H···A | D···A | D—H···A |
N11A—H11A···S12B | 0.791 (19) | 2.60 (2) | 3.391 (2) | 175.0 (19) |
N12A—H121···O11A | 0.77 (2) | 2.06 (2) | 2.669 (3) | 136 (2) |
N11B—H11B···S12A | 0.850 (19) | 2.606 (19) | 3.442 (2) | 168.2 (17) |
N12B—H124···O11B | 0.84 (3) | 1.92 (3) | 2.618 (3) | 140 (3) |
N12B—H123···S12Ai | 0.83 (3) | 2.49 (3) | 3.309 (3) | 170 (2) |
N12A—H122···S12Bii | 0.93 (3) | 2.55 (3) | 3.456 (2) | 167 (2) |
Symmetry codes: (i) x+1, y, z; (ii) x−1, y, z. |
Experimental details
Crystal data |
Chemical formula | C8H8N2OS |
Mr | 180.22 |
Crystal system, space group | Triclinic, P1 |
Temperature (K) | 293 |
a, b, c (Å) | 8.2300 (16), 9.3410 (18), 12.594 (3) |
α, β, γ (°) | 73.91 (3), 88.14 (3), 70.80 (3) |
V (Å3) | 876.7 (4) |
Z | 4 |
Radiation type | Mo Kα |
µ (mm−1) | 0.32 |
Crystal size (mm) | 0.30 × 0.15 × 0.10 |
|
Data collection |
Diffractometer | Kuma KM-4 four-circle diffractometer |
Absorption correction | – |
No. of measured, independent and observed [I > 2σ(I)] reflections | 3276, 3067, 1929 |
Rint | 0.025 |
(sin θ/λ)max (Å−1) | 0.596 |
|
Refinement |
R[F2 > 2σ(F2)], wR(F2), S | 0.034, 0.071, 1.00 |
No. of reflections | 3067 |
No. of parameters | 282 |
H-atom treatment | All H-atom parameters refined |
Δρmax, Δρmin (e Å−3) | 0.15, −0.21 |
Selected geometric parameters (Å, º) topS12A—C12A | 1.678 (2) | S12B—C12B | 1.679 (2) |
O11A—C11A | 1.220 (2) | O11B—C11B | 1.220 (3) |
N11A—C11A | 1.376 (3) | N11B—C11B | 1.382 (3) |
N11A—C12A | 1.377 (3) | N11B—C12B | 1.374 (3) |
N12A—C12A | 1.303 (3) | N12B—C12B | 1.295 (3) |
| | | |
S12A—C12A—N11A | 118.70 (17) | S12B—C12B—N11B | 120.50 (16) |
S12A—C12A—N12A | 122.97 (18) | S12B—C12B—N12B | 122.19 (18) |
N11A—C12A—N12A | 118.3 (2) | N11B—C12B—N12B | 117.3 (2) |
C11A—N11A—C12A | 128.0 (2) | C11B—N11B—C12B | 127.72 (19) |
| | | |
C6A—C1A—C11A—O11A | 135.1 (2) | C6B—C1B—C11B—O11B | 145.3 (2) |
Hydrogen-bond geometry (Å, º) top
D—H···A | D—H | H···A | D···A | D—H···A |
N11A—H11A···S12B | 0.791 (19) | 2.60 (2) | 3.391 (2) | 175.0 (19) |
N12A—H121···O11A | 0.77 (2) | 2.06 (2) | 2.669 (3) | 136 (2) |
N11B—H11B···S12A | 0.850 (19) | 2.606 (19) | 3.442 (2) | 168.2 (17) |
N12B—H124···O11B | 0.84 (3) | 1.92 (3) | 2.618 (3) | 140 (3) |
N12B—H123···S12Ai | 0.83 (3) | 2.49 (3) | 3.309 (3) | 170 (2) |
N12A—H122···S12Bii | 0.93 (3) | 2.55 (3) | 3.456 (2) | 167 (2) |
Symmetry codes: (i) x+1, y, z; (ii) x−1, y, z. |
Thiourea derivatives can be regarded as model compounds for different intra- and intermolecular interactions involving S atoms. In the literature, there are only a few structural reports describing these compounds, perhaps due to the reported difficulties in preparing crystals for X-ray diffraction studies (Shanmuga Sundara Raj et al., 1999). Therefore, we have carried out the X-ray structural study of a simple thiourea derivative, N-benzoyl-thiourea, (I). Our main goal of this study was to identify the patterns created by the intermolecular N—H···S interactions. \sch
The asymmetric part of the unit cell of (I) contains two molecules, hereinafter referred to as molecules A and B. The bond lengths and angles of these symmetry-independent molecules are quite similar. The normal probability plot analysis (Abrahams & Keve, 1971; International Tables for X-ray Crystallography, 1974, Vol. IV, pp. 293–309) shows that the differences are of a statistical rather than systematic nature; the correlation coefficients between experimental and theoretical distributions are 0.97 for bond lengths and 0.94 for bond angles. In fact, there is an approximate pseudo centre of symmetry between molecules A and B. Taking into account only C—CO-thiourea fragments, the coordinates of this pseudo centre are 0.704 (6), 0.78 (2), 0.502 (7). The phenyl rings deviate considerably from this approximate symmetry, the dihedral angle between the least-squares plane of the ring and the plane through the three atoms C11, O11, N11 being 42.9 (1)° in molecule A and 33.0 (1)° in B.
The C1/C11/O11/N11 and thiourea fragments are almost ideally planar, with the maximum deviations from the least-squares planes not exceeding 0.012 (2) Å. The dihedral angles between these planes are also small: 7.3 (1)° in A and 2.1 (2)° in B. This almost coplanar conformation is enforced by a strong intramolecular N12—H···O11 hydrogen bond that closes an almost planar six-membered ring [maximum deviations of 0.051 (6) and 0.015 (8) Å for molecules A and B, respectively]. The significantly more folded conformation of molecule A correlates well with the lengths of the intramolecular hydrogen bonds (Table 2). A similar conformation was found in a closely related compound, N-(4-methylbenzoyl)thiourea, (II) (Reinke, 2001). In that compound, the dihedral angle between two planar fragments is 5.8°, and the hydrogen bonds also have an intermediate length, with an N···O distance of 2.640 Å. Additional arguments for the decisive role of this hydrogen bond in the determination of molecular conformation can be obtained by an examination of the May 2002 release of the Cambridge Structural Database (Allen, 2002). For 28 fragments with primary and secondary N12 groups, the mean value of the improper OC···CN torsion angle is 3(2)° [for (I), this angle is 7.0 (2)° in molecule A and 1.0 (2)° in molecule B, while for (II), it is 3.5°], while for 26 compounds with tertiary groups, the mean value of this angle is 51 (7)° (after removal of two outliers).
The pattern of bond lengths and angles in (I) is quite typical. Both C═O and C═S bonds have double-bond character, and the C—N bonds in the thiourea fragment are significantly different. The C—NH2 bond is remarkably short, and it is one of the shortest C—N bonds found in thiourea derivatives.
The crystal packing in (I) is governed by two kinds of strong N—H···S hydrogen bonds (Table 2, Fig. 1) which form pseudo-centrosymmetric dimers of molecules A and B. These hydrogen bonds connect the molecules into ribbons along the [100] direction. These hydrophilic hydrogen-bonded channels are surrounded by the hydrophobic surface of the phenyl rings. Interestingly, the true centre of symmetry is not utilized in creating of the main structural pattern; instead, the structure uses two different molecules connected by approximate centres of symmetry. The molecule of (II) also crystallizes in the triclinic space group P1, but with Z = 2, and a similar packing is created by means of exact centres of symmetry. However, in this case, one of the N—H···S intermolecular hydrogen bonds is much longer than the other (3.711 Å).