organic compounds
2,3-Dihydrobenz[4,5]imidazo[2,1-b]thiazole
aNational Center of Energy Sciences and Nuclear Techniques, Rabat, Morocco, bLaboratory of Medicinal Chemistry, Faculty of Medicine and Pharmacy, Mohammed V University, Rabat, Morocco, cLaboratoire de Chimie Organique Heterocyclique URAC 21, Av. Ibn Battouta, BP 1014, Faculte des Sciences, Universite Mohammed V, Rabat, Morocco, and dDepartment of Chemistry, Tulane University, New Orleans, LA 70118, USA
*Correspondence e-mail: ahmed_moussaif@yahoo.com
The 9H8N2S, consists of two independent molecules (A and B) differing in the conformation of the thiazole ring: twisted for molecule A and planar for molecule B. In the crystal, molecules stack along the c axis in alternating A and B layers. Within the layers, molecules are linked by C—H⋯π interactions, and inversion-related B molecules are linked by offset π–π interactions [inter-centroid distance = 3.716 (1) Å]. The two molecules are also linked by a C—H⋯N hydrogen bond, which results finally in the formation of a three-dimensional structure.
of the title compound, CKeywords: crystal structure; thiazole; benzoimidazole; hydrogen bonding; π–π stacking; C—H⋯π interactions.
CCDC reference: 1520873
Structure description
An enormous variety of thiazolo[3,2-a]benzimidazoles, with unique pharmaceutical and medicinal applications, have been reported (Piskin et al., 2009; Le Sann et al., 2006). As a continuation of our research devoted to the development of benzimidazole derivatives (El Bakri et al. 2016), the title compound was prepared and characterized by single-crystal X-ray diffraction.
The , consists of two independent molecules (A and B), differing in the conformation of the five-membered thiazole ring. In molecule A, the ring (S1/N2/C7–C9) has a twisted conformation on the C8—C9 bond, while in molecule B the ring (S2/N4/C16–C18) is planar (r.m.s. deviation = 0.035 Å).
of the title compound, Fig. 1In the crystal, molecules stack along the c axis in alternating A and B layers (Fig. 2). Within the layers, molecules are linked by C—H⋯π interactions (Fig. 2 and Table 1), and inversion-related B molecules are linked by offset π–π interactions [Cg7⋯Cg9i = 3.716 (1) Å; Cg7 and Cg9 are the centroids of the S2/N4/C16–C18 and C10–C15 rings, respectively; interplanar distance = 3.638 (1) Å, slippage = 0.763 Å; symmetry code: (i) −x, −y + 1, −z + 1]. The two molecules are also linked by a C—H⋯N hydrogen bond (Table 1), which results finally in the formation of a three-dimensional structure (Fig. 2).
Synthesis and crystallization
To a solution of benzimidazole-2-thione (1 g, 7 mmol) in 20 ml of dimethylformamide, were added potassium bicarbonate (1.93 g, 14 mmol), bromotetrabutylammonium (0.1 mmol) and 1,2-dibromoethane (3.5 mmol). The reaction mixture was stirred at room temperature for 4 h. After evaporation of the solvent under reduced pressure, the residue was chromatographed on silica gel (hexane/ethyl acetate: 80/20), giving a solid product. Colourless plate-like crystals were obtained by recrystallization from ethanol solution to afford the title compound in 80% yield.
Refinement
Crystal data, data collection and structure .
details are summarized in Table 2
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Structural data
CCDC reference: 1520873
https://doi.org/10.1107/S2414314616019489/su4107sup1.cif
contains datablocks global, I. DOI:Structure factors: contains datablock I. DOI: https://doi.org/10.1107/S2414314616019489/su4107Isup2.hkl
Supporting information file. DOI: https://doi.org/10.1107/S2414314616019489/su4107Isup3.cml
Data collection: APEX3 (Bruker, 2016); cell
SAINT (Bruker, 2016); data reduction: SAINT (Bruker, 2016); program(s) used to solve structure: SHELXT (Sheldrick, 2015a); program(s) used to refine structure: SHELXL2014 (Sheldrick, 2015b); molecular graphics: DIAMOND (Brandenburg & Putz, 2012 and Mercury (Macrae et al., 2008); software used to prepare material for publication: SHELXTL (Sheldrick, 2008).C9H8N2S | F(000) = 736 |
Mr = 176.23 | Dx = 1.411 Mg m−3 |
Monoclinic, P21/c | Mo Kα radiation, λ = 0.71073 Å |
a = 12.7440 (8) Å | Cell parameters from 4421 reflections |
b = 11.4820 (7) Å | θ = 2.5–25.4° |
c = 12.8707 (8) Å | µ = 0.33 mm−1 |
β = 118.234 (1)° | T = 298 K |
V = 1659.25 (18) Å3 | Plate, colourless |
Z = 8 | 0.38 × 0.22 × 0.06 mm |
Bruker SMART APEX CCD diffractometer | 4244 independent reflections |
Radiation source: fine-focus sealed tube | 2702 reflections with I > 2σ(I) |
Graphite monochromator | Rint = 0.036 |
Detector resolution: 8.3333 pixels mm-1 | θmax = 29.1°, θmin = 1.8° |
φ and ω scans | h = −17→17 |
Absorption correction: multi-scan (SADABS; Bruker, 2016) | k = −15→15 |
Tmin = 0.87, Tmax = 0.98 | l = −16→17 |
15538 measured reflections |
Refinement on F2 | Primary atom site location: structure-invariant direct methods |
Least-squares matrix: full | Secondary atom site location: difference Fourier map |
R[F2 > 2σ(F2)] = 0.046 | Hydrogen site location: difference Fourier map |
wR(F2) = 0.134 | All H-atom parameters refined |
S = 1.02 | w = 1/[σ2(Fo2) + (0.0762P)2] where P = (Fo2 + 2Fc2)/3 |
4244 reflections | (Δ/σ)max = 0.001 |
281 parameters | Δρmax = 0.27 e Å−3 |
0 restraints | Δρmin = −0.25 e Å−3 |
Experimental. The diffraction data were collected in three sets of 363 frames (0.5° width in ω) at φ = 0, 120 and 240°. A scan time of 40 sec/frame was used. |
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. |
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 > 2sigma(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. |
x | y | z | Uiso*/Ueq | ||
S1 | 0.60928 (5) | 0.83270 (4) | 0.50755 (5) | 0.06186 (19) | |
N1 | 0.67791 (13) | 0.67804 (12) | 0.69522 (13) | 0.0494 (4) | |
N2 | 0.48777 (12) | 0.67647 (11) | 0.55018 (12) | 0.0423 (3) | |
C1 | 0.61392 (15) | 0.59028 (14) | 0.71572 (15) | 0.0433 (4) | |
C2 | 0.65137 (19) | 0.51054 (16) | 0.80769 (17) | 0.0530 (5) | |
H2 | 0.7323 (17) | 0.5100 (17) | 0.8657 (17) | 0.067 (6)* | |
C3 | 0.5701 (2) | 0.43030 (17) | 0.80575 (18) | 0.0571 (5) | |
H3 | 0.5961 (19) | 0.375 (2) | 0.8645 (19) | 0.076 (6)* | |
C4 | 0.4535 (2) | 0.42874 (17) | 0.71608 (19) | 0.0585 (5) | |
H4 | 0.3984 (17) | 0.3748 (19) | 0.7162 (17) | 0.067 (6)* | |
C5 | 0.41276 (17) | 0.50738 (16) | 0.62405 (17) | 0.0503 (4) | |
H5 | 0.3330 (18) | 0.5108 (18) | 0.5642 (16) | 0.064 (6)* | |
C6 | 0.49469 (14) | 0.58756 (13) | 0.62549 (14) | 0.0408 (4) | |
C7 | 0.59884 (15) | 0.72369 (15) | 0.59596 (15) | 0.0442 (4) | |
C8 | 0.40008 (17) | 0.71382 (17) | 0.43372 (16) | 0.0489 (4) | |
H8A | 0.3903 (15) | 0.6550 (16) | 0.3759 (15) | 0.047 (5)* | |
H8B | 0.3277 (17) | 0.7257 (16) | 0.4307 (15) | 0.054 (5)* | |
C9 | 0.4497 (2) | 0.8251 (2) | 0.4088 (2) | 0.0637 (6) | |
H9A | 0.435 (2) | 0.8278 (18) | 0.330 (2) | 0.080 (7)* | |
H9B | 0.4210 (19) | 0.895 (2) | 0.4243 (19) | 0.084 (8)* | |
S2 | 0.09273 (5) | 0.81657 (5) | 0.59932 (5) | 0.06511 (19) | |
N3 | 0.14754 (13) | 0.66410 (13) | 0.46357 (14) | 0.0531 (4) | |
N4 | −0.03893 (13) | 0.66826 (12) | 0.43993 (13) | 0.0447 (3) | |
C10 | 0.07636 (16) | 0.58368 (15) | 0.37754 (16) | 0.0480 (4) | |
C11 | 0.1060 (2) | 0.50724 (18) | 0.31224 (19) | 0.0605 (5) | |
H11 | 0.1862 (18) | 0.5015 (17) | 0.3240 (16) | 0.066 (6)* | |
C12 | 0.0190 (2) | 0.43527 (18) | 0.2334 (2) | 0.0686 (6) | |
H12 | 0.0374 (18) | 0.384 (2) | 0.1871 (18) | 0.073 (6)* | |
C13 | −0.0963 (2) | 0.43830 (19) | 0.2175 (2) | 0.0716 (6) | |
H13 | −0.152 (2) | 0.389 (2) | 0.166 (2) | 0.091 (8)* | |
C14 | −0.12870 (19) | 0.51306 (18) | 0.28185 (18) | 0.0591 (5) | |
H14 | −0.203 (2) | 0.512 (2) | 0.2730 (19) | 0.084 (7)* | |
C15 | −0.04071 (15) | 0.58468 (14) | 0.36185 (15) | 0.0442 (4) | |
C16 | 0.07387 (15) | 0.71029 (15) | 0.49625 (15) | 0.0469 (4) | |
C17 | −0.12433 (18) | 0.71370 (19) | 0.47270 (19) | 0.0520 (5) | |
H17A | −0.1465 (16) | 0.6577 (16) | 0.5092 (16) | 0.053 (5)* | |
H17B | −0.1870 (19) | 0.740 (2) | 0.4091 (19) | 0.075 (7)* | |
C18 | −0.0634 (2) | 0.8086 (3) | 0.5617 (3) | 0.0783 (7) | |
H18A | −0.070 (3) | 0.805 (3) | 0.625 (3) | 0.131 (13)* | |
H18B | −0.094 (3) | 0.885 (3) | 0.530 (3) | 0.140 (13)* |
U11 | U22 | U33 | U12 | U13 | U23 | |
S1 | 0.0674 (4) | 0.0543 (3) | 0.0757 (4) | −0.0089 (2) | 0.0435 (3) | 0.0056 (2) |
N1 | 0.0439 (8) | 0.0468 (8) | 0.0566 (9) | −0.0006 (6) | 0.0230 (8) | −0.0052 (7) |
N2 | 0.0413 (8) | 0.0416 (8) | 0.0472 (8) | −0.0001 (6) | 0.0235 (7) | 0.0012 (6) |
C1 | 0.0447 (10) | 0.0410 (8) | 0.0463 (9) | 0.0037 (7) | 0.0234 (8) | −0.0053 (7) |
C2 | 0.0562 (12) | 0.0519 (11) | 0.0466 (10) | 0.0112 (9) | 0.0208 (9) | −0.0023 (8) |
C3 | 0.0768 (15) | 0.0488 (11) | 0.0510 (11) | 0.0088 (10) | 0.0347 (11) | 0.0075 (9) |
C4 | 0.0698 (14) | 0.0514 (11) | 0.0667 (13) | −0.0033 (10) | 0.0425 (12) | 0.0069 (9) |
C5 | 0.0467 (11) | 0.0521 (10) | 0.0566 (11) | −0.0026 (8) | 0.0282 (9) | 0.0031 (9) |
C6 | 0.0442 (9) | 0.0388 (8) | 0.0444 (9) | 0.0026 (7) | 0.0250 (8) | −0.0015 (7) |
C7 | 0.0458 (10) | 0.0389 (9) | 0.0549 (11) | −0.0022 (7) | 0.0295 (9) | −0.0065 (7) |
C8 | 0.0495 (11) | 0.0529 (11) | 0.0459 (10) | 0.0042 (9) | 0.0238 (9) | 0.0050 (9) |
C9 | 0.0703 (15) | 0.0566 (13) | 0.0652 (14) | 0.0022 (10) | 0.0329 (12) | 0.0119 (10) |
S2 | 0.0623 (4) | 0.0667 (4) | 0.0651 (4) | −0.0156 (2) | 0.0291 (3) | −0.0188 (2) |
N3 | 0.0410 (9) | 0.0622 (10) | 0.0572 (9) | −0.0010 (7) | 0.0242 (8) | −0.0005 (7) |
N4 | 0.0386 (8) | 0.0468 (8) | 0.0481 (8) | 0.0000 (6) | 0.0200 (7) | −0.0020 (6) |
C10 | 0.0489 (10) | 0.0487 (10) | 0.0493 (10) | 0.0088 (8) | 0.0255 (9) | 0.0107 (8) |
C11 | 0.0673 (14) | 0.0630 (12) | 0.0626 (13) | 0.0156 (11) | 0.0400 (12) | 0.0100 (10) |
C12 | 0.0960 (18) | 0.0571 (12) | 0.0657 (14) | 0.0089 (12) | 0.0487 (14) | −0.0015 (11) |
C13 | 0.0914 (18) | 0.0595 (13) | 0.0663 (14) | −0.0141 (12) | 0.0393 (14) | −0.0150 (11) |
C14 | 0.0571 (13) | 0.0608 (12) | 0.0614 (12) | −0.0111 (10) | 0.0297 (11) | −0.0076 (10) |
C15 | 0.0477 (10) | 0.0408 (8) | 0.0465 (9) | 0.0007 (7) | 0.0242 (8) | 0.0027 (7) |
C16 | 0.0427 (10) | 0.0480 (9) | 0.0467 (10) | −0.0032 (8) | 0.0184 (8) | 0.0017 (8) |
C17 | 0.0496 (11) | 0.0583 (11) | 0.0543 (12) | 0.0018 (9) | 0.0298 (10) | 0.0017 (10) |
C18 | 0.0618 (14) | 0.0847 (18) | 0.0860 (18) | 0.0015 (13) | 0.0330 (14) | −0.0303 (15) |
S1—C7 | 1.7385 (18) | S2—C16 | 1.7336 (18) |
S1—C9 | 1.821 (3) | S2—C18 | 1.813 (3) |
N1—C7 | 1.305 (2) | N3—C16 | 1.309 (2) |
N1—C1 | 1.398 (2) | N3—C10 | 1.397 (2) |
N2—C7 | 1.362 (2) | N4—C16 | 1.356 (2) |
N2—C6 | 1.381 (2) | N4—C15 | 1.382 (2) |
N2—C8 | 1.447 (2) | N4—C17 | 1.438 (2) |
C1—C2 | 1.390 (3) | C10—C11 | 1.385 (3) |
C1—C6 | 1.410 (2) | C10—C15 | 1.408 (2) |
C2—C3 | 1.378 (3) | C11—C12 | 1.370 (3) |
C2—H2 | 0.945 (19) | C11—H11 | 0.961 (19) |
C3—C4 | 1.384 (3) | C12—C13 | 1.385 (3) |
C3—H3 | 0.92 (2) | C12—H12 | 0.94 (2) |
C4—C5 | 1.381 (3) | C13—C14 | 1.385 (3) |
C4—H4 | 0.94 (2) | C13—H13 | 0.90 (2) |
C5—C6 | 1.386 (2) | C14—C15 | 1.379 (3) |
C5—H5 | 0.942 (19) | C14—H14 | 0.90 (2) |
C8—C9 | 1.525 (3) | C17—C18 | 1.503 (3) |
C8—H8A | 0.968 (18) | C17—H17A | 0.917 (19) |
C8—H8B | 0.915 (19) | C17—H17B | 0.88 (2) |
C9—H9A | 0.94 (2) | C18—H18A | 0.85 (3) |
C9—H9B | 0.94 (2) | C18—H18B | 0.97 (3) |
C7—S1—C9 | 90.94 (9) | C16—S2—C18 | 91.29 (10) |
C7—N1—C1 | 103.00 (14) | C16—N3—C10 | 103.12 (14) |
C7—N2—C6 | 106.40 (14) | C16—N4—C15 | 106.52 (14) |
C7—N2—C8 | 117.73 (14) | C16—N4—C17 | 118.16 (15) |
C6—N2—C8 | 135.01 (15) | C15—N4—C17 | 135.30 (15) |
C2—C1—N1 | 129.76 (17) | C11—C10—N3 | 129.68 (18) |
C2—C1—C6 | 119.26 (17) | C11—C10—C15 | 119.51 (18) |
N1—C1—C6 | 110.98 (15) | N3—C10—C15 | 110.80 (15) |
C3—C2—C1 | 118.20 (19) | C12—C11—C10 | 118.3 (2) |
C3—C2—H2 | 122.7 (12) | C12—C11—H11 | 120.2 (12) |
C1—C2—H2 | 119.0 (12) | C10—C11—H11 | 121.5 (12) |
C2—C3—C4 | 121.65 (19) | C11—C12—C13 | 121.7 (2) |
C2—C3—H3 | 118.0 (14) | C11—C12—H12 | 119.2 (13) |
C4—C3—H3 | 120.3 (14) | C13—C12—H12 | 119.1 (13) |
C5—C4—C3 | 121.78 (19) | C12—C13—C14 | 121.5 (2) |
C5—C4—H4 | 117.1 (13) | C12—C13—H13 | 119.9 (17) |
C3—C4—H4 | 121.1 (13) | C14—C13—H13 | 118.5 (17) |
C4—C5—C6 | 116.60 (18) | C15—C14—C13 | 116.7 (2) |
C4—C5—H5 | 123.5 (12) | C15—C14—H14 | 122.5 (15) |
C6—C5—H5 | 119.8 (12) | C13—C14—H14 | 120.7 (15) |
N2—C6—C5 | 133.16 (16) | C14—C15—N4 | 133.23 (17) |
N2—C6—C1 | 104.34 (14) | C14—C15—C10 | 122.31 (17) |
C5—C6—C1 | 122.50 (16) | N4—C15—C10 | 104.46 (15) |
N1—C7—N2 | 115.25 (15) | N3—C16—N4 | 115.10 (16) |
N1—C7—S1 | 131.83 (14) | N3—C16—S2 | 132.09 (14) |
N2—C7—S1 | 112.90 (13) | N4—C16—S2 | 112.81 (13) |
N2—C8—C9 | 105.81 (16) | N4—C17—C18 | 107.23 (17) |
N2—C8—H8A | 110.2 (11) | N4—C17—H17A | 110.8 (12) |
C9—C8—H8A | 109.8 (10) | C18—C17—H17A | 107.0 (12) |
N2—C8—H8B | 110.9 (11) | N4—C17—H17B | 109.3 (14) |
C9—C8—H8B | 112.1 (12) | C18—C17—H17B | 111.7 (15) |
H8A—C8—H8B | 108.1 (15) | H17A—C17—H17B | 110.8 (18) |
C8—C9—S1 | 109.29 (15) | C17—C18—S2 | 110.27 (16) |
C8—C9—H9A | 111.2 (14) | C17—C18—H18A | 116 (2) |
S1—C9—H9A | 109.9 (14) | S2—C18—H18A | 109 (2) |
C8—C9—H9B | 115.4 (14) | C17—C18—H18B | 112 (2) |
S1—C9—H9B | 103.2 (13) | S2—C18—H18B | 104.2 (19) |
H9A—C9—H9B | 107.5 (19) | H18A—C18—H18B | 104 (3) |
C7—N1—C1—C2 | 179.00 (17) | C16—N3—C10—C11 | −178.96 (19) |
C7—N1—C1—C6 | −0.63 (17) | C16—N3—C10—C15 | −0.18 (19) |
N1—C1—C2—C3 | −178.60 (17) | N3—C10—C11—C12 | 179.12 (18) |
C6—C1—C2—C3 | 1.0 (2) | C15—C10—C11—C12 | 0.4 (3) |
C1—C2—C3—C4 | −0.8 (3) | C10—C11—C12—C13 | 0.5 (3) |
C2—C3—C4—C5 | 0.0 (3) | C11—C12—C13—C14 | −1.0 (4) |
C3—C4—C5—C6 | 0.4 (3) | C12—C13—C14—C15 | 0.4 (3) |
C7—N2—C6—C5 | −178.18 (18) | C13—C14—C15—N4 | −179.87 (19) |
C8—N2—C6—C5 | −9.5 (3) | C13—C14—C15—C10 | 0.6 (3) |
C7—N2—C6—C1 | 1.27 (16) | C16—N4—C15—C14 | 180.0 (2) |
C8—N2—C6—C1 | 169.95 (17) | C17—N4—C15—C14 | 1.7 (3) |
C4—C5—C6—N2 | 179.21 (17) | C16—N4—C15—C10 | −0.44 (18) |
C4—C5—C6—C1 | −0.2 (3) | C17—N4—C15—C10 | −178.74 (19) |
C2—C1—C6—N2 | 179.90 (14) | C11—C10—C15—C14 | −1.0 (3) |
N1—C1—C6—N2 | −0.42 (17) | N3—C10—C15—C14 | −179.95 (17) |
C2—C1—C6—C5 | −0.6 (2) | C11—C10—C15—N4 | 179.32 (16) |
N1—C1—C6—C5 | 179.10 (15) | N3—C10—C15—N4 | 0.40 (18) |
C1—N1—C7—N2 | 1.54 (18) | C10—N3—C16—N4 | −0.1 (2) |
C1—N1—C7—S1 | −176.53 (14) | C10—N3—C16—S2 | 179.86 (15) |
C6—N2—C7—N1 | −1.88 (19) | C15—N4—C16—N3 | 0.4 (2) |
C8—N2—C7—N1 | −172.86 (15) | C17—N4—C16—N3 | 179.02 (16) |
C6—N2—C7—S1 | 176.57 (11) | C15—N4—C16—S2 | −179.61 (11) |
C8—N2—C7—S1 | 5.59 (19) | C17—N4—C16—S2 | −1.0 (2) |
C9—S1—C7—N1 | −176.19 (18) | C18—S2—C16—N3 | 178.1 (2) |
C9—S1—C7—N2 | 5.70 (14) | C18—S2—C16—N4 | −1.92 (17) |
C7—N2—C8—C9 | −16.1 (2) | C16—N4—C17—C18 | 4.0 (3) |
C6—N2—C8—C9 | 176.18 (18) | C15—N4—C17—C18 | −177.8 (2) |
N2—C8—C9—S1 | 18.9 (2) | N4—C17—C18—S2 | −5.1 (3) |
C7—S1—C9—C8 | −14.46 (17) | C16—S2—C18—C17 | 4.1 (2) |
Cg3, Cg7 and Cg9 are the centroids of the C1–C6, S2/N4/C16–C18 and C10–C15 rings, respectively. |
D—H···A | D—H | H···A | D···A | D—H···A |
C8—H8B···N3 | 0.92 (2) | 2.62 (2) | 3.464 (2) | 154 (2) |
C8—H8A···Cg3i | 0.97 (2) | 2.65 (2) | 3.543 (2) | 154 (2) |
C9—H9A···Cg3ii | 0.94 (2) | 2.99 (2) | 3.661 (3) | 129 (2) |
C12—H12···Cg7iii | 0.94 (2) | 2.94 (2) | 3.838 (2) | 161 (2) |
C18—H18A···Cg9iv | 0.85 (3) | 2.90 (3) | 3.471 (4) | 126 (3) |
Symmetry codes: (i) −x+1, −y+1, −z+1; (ii) x, −y+3/2, z−1/2; (iii) −x, y−1/2, −z+1/2; (iv) x, −y+3/2, z+1/2. |
Acknowledgements
JTM thanks Tulane University for support of the Tulane Crystallography Laboratory.
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