research communications
E)-2-(5-bromo-2-hydroxybenzylidene)hydrazinecarbothioamide dimethyl sulfoxide monosolvate
and Hirshfeld surface analysis of (aDepartment of Chemistry, Government Arts College (Autonomous), Thanthonimalai, Karur- 639 005, Tamil Nadu, India
*Correspondence e-mail: manavaibala@gmail.com
The molecule of the title Schiff base, C8H8BrN3OS·C2H6OS, which crystallizes as a dimethyl sulfoxide (DMSO) monosolvate, displays an E configuration with respect to the C=N bond, with a dihedral angle of 14.54 (11)° between the benzene ring and the mean plane of the N—N—C(N)=S unit. In the crystal, molecules are linked by N—H⋯O hydrogen bonds, forming chains propagating along the b-axis direction. Within the chains there are R23(11) ring motifs, which are reinforced by C—H⋯ODMSO hydrogen bonds enclosing secondary R12(6) and R23(9) loops. The chains are linked by O—Hhydroxyl⋯S hydrogen bonds, forming layers parallel to (011). Inversion-related layers are linked by short Br⋯Br interactions [3.5585 (5) Å], forming slabs parallel to (011). The intermolecular interactions have been investigated using Hirshfeld surface studies and two-dimensional fingerprint plots. The of the unsolvated form of the title compound has been reported previously [Kargar et al. (2010). Acta Cryst. E66, o2999], and its solid-state structure is compared with that of the title solvated form.
Keywords: crystal structure; Schiff base; hydrazinecarbothioamide; hydrogen bonding; Hirshfeld surface analysis.
CCDC reference: 1587285
1. Chemical context
). Thiosemicarbazones exhibit interesting pharmacological properties and biological activities. Thiosemicarbazone derivatives have gained special importance because of their role in drug development; for example they are used as antiviral, antitubercular, anti-bacterial infection, analgesic and antiallergic agents and in the treatment of central nervous system disorders and as sodium channel blockers and show antitumorous activity. The pharmacological versatility of thiosemicarbazones and their metal complexes have been reviewed by Beraldo & Gambino (2004).
are nitrogen-containing active organic compounds that play a vital role in enzymatic reactions involving interaction of an enzyme with a carbonyl group of a substrate (Tidwell, 2008Thiosemicarbazones are formed by the condensation of thiosemicarbazides with et al., 2006; Scovill et al., 1982). They are also used in most branches of chemistry, for example, as dyes, photographic films, plastics and in the textile industry. These types of compounds also act as ligands for a variety of transition metals, often as high propensity multi-dentate chelating agents (Al-Karawi et al., 2009). Herein, we report on the of the title thiosemicarbazone that crystallizes as a dimethyl sulfoxide monosolvate. The of the unsolvated form of the title Schiff base has been reported previously (Kargar et al., 2010a), and its solid-state structure is compared with that of the title solvated form.
or (Sriram2. Structural commentary
The molecular structure of the title compound is shown in Fig. 1. The thiosemicarbazone molecule has an E configurationabout the C7=N1 bond. The molecule is twisted with a dihedral angle of 14.54 (11)° between the benzene ring and the mean plane of the N1/N2/C8/N3/S1 unit. The C8—-S1 bond distance of 1.698 (2) Å is close to that expected for a C=S bond (Cambridge Structural Database; Groom et al., 2016). This confirms the existence of the compound in the thioamido form in the solid state, similar to the situation observed in some related compounds, viz. (E)-2-(2,4-dihydroxybenzylidene)thiosemicarbazone and (E)-2-[(1H-indol-3-yl)methylene]thiosemicarbazone (Yıldız et al., 2009). The C1—N7 bond distance is 1.278 (3) Å, close to that of a C=N double bond, confirming the azomethine bond formation, again similar to the situation observed in related compounds, viz. (E)-1-[4-(dimethylamino)benzylidene]thiosemicarbazide (Sun et al. 2009) and 2-[(2-hydroxynaphthalen-1-yl)methylene]hydrazinecarbothioamide (Sivajeyanthi et al. 2017).
In the molecular structure of the unsolvated form of the title compound (Kargar et al., 2010a), an intramolecular O—H⋯N hydrogen bond is present enclosing an S(6) ring motif. Comparing the two molecules, as shown in the structural overlay of Fig. 2, it can be seen that the benzene ring of the title solvated compound is rotated by ca. 180° with respect to that in the unsolvated form of the molecule. The bond lengths and bond angles of the two molecules are similar. In the title compound, the dihedral angle between the benzene ring and the mean plane of the N—N—C(N)=S hydrazinecarbothioamide unit is 14.54 (11)° compared to ca 7.05° in the unsolvated phase. Kargar et al. (2010b) have also reported the of the unsolvated chloro-substituted analogue. This molecule has the same conformation as the unsolvated bromo-substituted analogue (Kargar et al., 2010a), but in contrast it crystallizes in the monoclinic P21/c, while the unsolvated bromo compound crystallizes in the chiral orthorhombic P212121.
3. Supramolecular features
In the crystal, the Schiff base hydrazone is hydrogen bonded (see Table 1) to the dimethyl sulfoxide solvate molecule, forming a chain propagating along the b-axis direction, as shown in Fig. 3. Within the chains there are R32(11) ring motifs, which are reinforced by C—H⋯ODMSO hydrogen bonds enclosing secondary R21(6) and R32(9) ring motifs (Table 1). The R32(11) ring motif is formed by N2—H2⋯O2ii, N3—H3A⋯O1iii and N3—H3B⋯O2iv hydrogen-bonding interactions, and the R21(6) ring motif is formed via C7—H7⋯O2ii and N2—H2⋯O2ii hydrogen-bonding interactions. Hence, atom O2 of the dimethyl sulfoxide acts as a trifurcated acceptor (Fig. 3, Table 1). The chains are linked by O1—H1⋯Si hydrogen bonds, forming layers parallel to plane (011); see Fig. 4 and Table 1. Inversion-related layers are linked by short Br⋯Br(−x, −y + 1, −z + 1) interactions of 3.5585 (5) Å, forming slabs parallel to (011), as illustrated in Fig. 5.
4. Hirshfeld surface analysis
The three-dimensional dnorm surface is a useful tool to analyse and visualize the inter-molecular interactions. dnorm takes negative or positive values depending on whether the intermolecular contact is shorter or longer than the van der Waals radii (Spackman & Jayatilaka, 2009; McKinnon et al., 2007). The three-dimensional dnorm surface of the title compound is shown in Fig. 6. The red points, which represent closer contacts and negative dnorm values on the surface, correspond to the N—H⋯O, O—H⋯S and C—H⋯O interactions. The percentage contributions of various contacts to the total Hirshfeld surface are as follows: H⋯H (32.9%), S⋯H/H⋯S (18.8%), O⋯H/H⋯O (13.3%), Br⋯H/H⋯Br (11.6), C⋯H/H⋯C (8.8%), N⋯H/H⋯N (3.4%), C⋯C (2.8%), Br⋯N/N⋯Br (2.0%), Br⋯Br (1.5%), Br⋯O/O⋯Br (1.1%), Br⋯C/C⋯Br (1.1%), C⋯N/N⋯C (1.0%), S⋯S (0.7%), S⋯N/N⋯S (0.6%) and S⋯C/C⋯S (0.2%), as shown in the two-dimensional fingerprint plots in Fig. 7.
5. Database survey
A search of the Cambridge Structural Database (Version 5.38, update May 2017; Groom et al., 2016) for the 2-hydroxybenzaldehyde thiosemicarbazone skeleton (or salicylaldehyde thiosemicarbazone) yielded 25 hits. These include the unsolvated bromo- and chloro-substituted analogues of the title compound mentioned above, viz. 5-bromo-2-hydroxybenzaldehyde thiosemicarbazone (CEDPAE; Kargar et al., 2010a) and 2-(5-chloro-2-hydroxybenzylidene)hydrazinecarbothioamide (VACGUD; Kargar et al., 2010b). The of salicylaldehyde thiosemicarbazone has also been reported at 295 K (GEXKID; Chattopadhyay et al., 1988) and at 100 K (GEXKID01; Novaković et al., 2007). The crystal structures of various hydrated forms of salicylaldehydethiosemicarbazone [(E)-2-(2-hydroxybenzylidene)hydrazinecarbothioamide hydrate] have been reported at 100 K (UJIPIN) and 203 K (UJIPOT and UJIPUZ) by Monfared et al. (2010). In the majority of the hits, the 2-hydroxy group forms an intramolecular O—H⋯N hydrogen bond, as shown for CEDPAE in Fig. 2. Consequently, in the compounds mentioned above, the dihedral angle between the benzene ring and the mean plane of the N—N—C(N)=S hydrazinecarbothioamide unit is relatively small, varying from ca 5.62 to 10.10°, compared to 14.54 (11)° in the title compound.
6. Synthesis and crystallization
The title compound was synthesized by refluxing for 8 h a 1:1 molar ratio of a hot ethanolic solution (20 ml) of thiosemicarbazide (0.091 mg, Aldrich) and a hot ethanolic solution of 5-bromosalicylaldehyde (0.196 mg, Aldrich). The solution was then cooled and kept at room temperature. The precipitate that formed was filtered off and recrystallized from dimethyl sulfoxide. Colourless block-like crystals, suitable for the X-ray analysis, were obtained in a few days on slow evaporation of the solvent.
7. Refinement
Crystal data, data collection and structure . The hydrogen atoms were fixed geometrically (O—H = 0.82, N—H = 0.86, C—H = 0.93–0.96 Å) and allowed to ride on their parent atoms with Uiso(H) = 1.5Ueq(O-hydroxyl, C-methyl) and 1.2Ueq(N,C) for other H atoms.
details are summarized in Table 2Supporting information
CCDC reference: 1587285
https://doi.org/10.1107/S2056989018000233/su5414sup1.cif
contains datablocks global, I, 1. DOI:Structure factors: contains datablock I. DOI: https://doi.org/10.1107/S2056989018000233/su5414Isup2.hkl
Supporting information file. DOI: https://doi.org/10.1107/S2056989018000233/su5414Isup3.cml
Data collection: APEX2 (Bruker, 2004); cell
APEX2 and SAINT (Bruker, 2004); data reduction: SAINT and XPREP (Bruker, 2004); program(s) used to solve structure: SIR92 (Altomare et al., 1993); program(s) used to refine structure: SHELXL2017/1 (Sheldrick, 2015); molecular graphics: PLATON (Spek 2009) and Mercury (Macrae et al., 2008); software used to prepare material for publication: SHELXL2017/1 (Sheldrick, 2015), PLATON (Spek 2009) and publCIF (Westrip, 2010).C8H8BrN3OS·C2H6OS | Z = 2 |
Mr = 352.26 | F(000) = 356 |
Triclinic, P1 | Dx = 1.637 Mg m−3 |
a = 6.5411 (4) Å | Mo Kα radiation, λ = 0.71073 Å |
b = 7.3889 (6) Å | Cell parameters from 2934 reflections |
c = 15.0662 (12) Å | θ = 5.5–55.9° |
α = 78.772 (3)° | µ = 3.17 mm−1 |
β = 86.872 (3)° | T = 296 K |
γ = 87.376 (3)° | Block, colourless |
V = 712.71 (9) Å3 | 0.30 × 0.20 × 0.20 mm |
Bruker Kappa APEXII CCD diffractometer | 2661 reflections with I > 2σ(I) |
Radiation source: fine-focus sealed tube | Rint = 0.018 |
ω and φ scan | θmax = 28.3°, θmin = 3.4° |
Absorption correction: multi-scan (SADABS; Bruker, 2004) | h = −8→6 |
Tmin = 0.449, Tmax = 0.569 | k = −9→9 |
6030 measured reflections | l = −17→19 |
3299 independent 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)] = 0.030 | Hydrogen site location: inferred from neighbouring sites |
wR(F2) = 0.106 | H-atom parameters constrained |
S = 0.79 | w = 1/[σ2(Fo2) + (0.1P)2] where P = (Fo2 + 2Fc2)/3 |
3299 reflections | (Δ/σ)max = 0.001 |
165 parameters | Δρmax = 0.27 e Å−3 |
0 restraints | Δρmin = −0.34 e Å−3 |
Geometry. Bond distances, angles etc. have been calculated using the rounded fractional coordinates. All su's are estimated from the variances of the (full) variance-covariance matrix. The cell esds are taken into account in the estimation of distances, angles and torsion angles |
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 | ||
Br1 | 0.20262 (4) | 0.63938 (4) | 0.51812 (2) | 0.0512 (1) | |
S1 | 1.36501 (8) | 0.37819 (8) | 0.83370 (4) | 0.0359 (2) | |
S2 | 0.24643 (10) | 0.89596 (8) | 0.93448 (4) | 0.0421 (2) | |
O1 | 0.6312 (2) | 1.1359 (2) | 0.71559 (12) | 0.0382 (5) | |
N1 | 0.8705 (3) | 0.6223 (3) | 0.72520 (13) | 0.0300 (5) | |
N2 | 1.0553 (3) | 0.5884 (2) | 0.76701 (13) | 0.0305 (5) | |
N3 | 1.0303 (3) | 0.2820 (3) | 0.76421 (15) | 0.0389 (6) | |
C1 | 0.6169 (3) | 0.8495 (3) | 0.66806 (14) | 0.0267 (6) | |
O2 | 0.1487 (3) | 0.9012 (2) | 0.84564 (14) | 0.0512 (6) | |
C2 | 0.5325 (3) | 1.0274 (3) | 0.66902 (15) | 0.0287 (6) | |
C3 | 0.3559 (3) | 1.0884 (3) | 0.62389 (16) | 0.0346 (7) | |
C4 | 0.2574 (4) | 0.9727 (3) | 0.57957 (17) | 0.0385 (7) | |
C5 | 0.3383 (3) | 0.7961 (3) | 0.58003 (15) | 0.0325 (6) | |
C6 | 0.5159 (3) | 0.7339 (3) | 0.62232 (15) | 0.0309 (6) | |
C7 | 0.8054 (3) | 0.7906 (3) | 0.71317 (15) | 0.0300 (6) | |
C8 | 1.1348 (3) | 0.4159 (3) | 0.78513 (14) | 0.0274 (6) | |
C9 | 0.5074 (4) | 0.8287 (4) | 0.9172 (2) | 0.0493 (9) | |
C10 | 0.1671 (5) | 0.6884 (4) | 1.0067 (2) | 0.0578 (10) | |
H1 | 0.54961 | 1.21258 | 0.73121 | 0.0570* | |
H2 | 1.11849 | 0.67747 | 0.78122 | 0.0360* | |
H3 | 0.30338 | 1.20764 | 0.62341 | 0.0410* | |
H3A | 0.91417 | 0.30700 | 0.73958 | 0.0470* | |
H3B | 1.07844 | 0.17008 | 0.77525 | 0.0470* | |
H4 | 0.13811 | 1.01311 | 0.54976 | 0.0460* | |
H6 | 0.56908 | 0.61567 | 0.62069 | 0.0370* | |
H7 | 0.88039 | 0.87680 | 0.73376 | 0.0360* | |
H9A | 0.51533 | 0.72024 | 0.89072 | 0.0740* | |
H9B | 0.57191 | 0.80243 | 0.97422 | 0.0740* | |
H9C | 0.57610 | 0.92693 | 0.87721 | 0.0740* | |
H10A | 0.02145 | 0.69522 | 1.01827 | 0.0870* | |
H10B | 0.23443 | 0.67244 | 1.06288 | 0.0870* | |
H10C | 0.20263 | 0.58551 | 0.97788 | 0.0870* |
U11 | U22 | U33 | U12 | U13 | U23 | |
Br1 | 0.0489 (2) | 0.0567 (2) | 0.0538 (2) | −0.0095 (1) | −0.0172 (1) | −0.0193 (1) |
S1 | 0.0323 (3) | 0.0315 (3) | 0.0469 (4) | 0.0088 (2) | −0.0164 (2) | −0.0132 (2) |
S2 | 0.0571 (4) | 0.0295 (3) | 0.0432 (4) | −0.0032 (3) | −0.0125 (3) | −0.0124 (3) |
O1 | 0.0344 (8) | 0.0356 (8) | 0.0498 (10) | 0.0071 (7) | −0.0122 (7) | −0.0203 (7) |
N1 | 0.0244 (8) | 0.0301 (9) | 0.0365 (10) | 0.0043 (7) | −0.0081 (7) | −0.0086 (7) |
N2 | 0.0273 (9) | 0.0241 (8) | 0.0417 (11) | 0.0023 (7) | −0.0132 (7) | −0.0082 (7) |
N3 | 0.0374 (10) | 0.0260 (9) | 0.0566 (14) | 0.0019 (8) | −0.0182 (9) | −0.0123 (9) |
C1 | 0.0254 (10) | 0.0273 (10) | 0.0267 (10) | 0.0031 (8) | −0.0038 (7) | −0.0040 (8) |
O2 | 0.0724 (13) | 0.0296 (8) | 0.0554 (12) | 0.0027 (8) | −0.0339 (10) | −0.0099 (8) |
C2 | 0.0294 (10) | 0.0280 (10) | 0.0288 (11) | 0.0017 (8) | −0.0032 (8) | −0.0057 (8) |
C3 | 0.0341 (11) | 0.0302 (11) | 0.0390 (13) | 0.0091 (9) | −0.0089 (9) | −0.0059 (9) |
C4 | 0.0303 (11) | 0.0460 (13) | 0.0373 (13) | 0.0063 (10) | −0.0115 (9) | −0.0024 (10) |
C5 | 0.0314 (10) | 0.0377 (11) | 0.0289 (11) | −0.0033 (9) | −0.0054 (8) | −0.0063 (9) |
C6 | 0.0328 (11) | 0.0306 (10) | 0.0297 (11) | 0.0012 (8) | −0.0047 (8) | −0.0063 (9) |
C7 | 0.0306 (11) | 0.0290 (10) | 0.0314 (11) | 0.0008 (8) | −0.0039 (8) | −0.0084 (8) |
C8 | 0.0283 (10) | 0.0249 (10) | 0.0301 (11) | 0.0030 (8) | −0.0031 (8) | −0.0083 (8) |
C9 | 0.0524 (16) | 0.0504 (15) | 0.0462 (16) | −0.0097 (12) | −0.0098 (12) | −0.0079 (12) |
C10 | 0.0619 (18) | 0.0567 (17) | 0.0521 (18) | −0.0143 (14) | 0.0035 (13) | −0.0025 (14) |
Br1—C5 | 1.898 (2) | N3—H3B | 0.8600 |
S1—C8 | 1.698 (2) | C3—C4 | 1.383 (3) |
S2—C10 | 1.780 (3) | N3—H3A | 0.8600 |
S2—O2 | 1.508 (2) | C4—C5 | 1.384 (3) |
S2—C9 | 1.776 (3) | C5—C6 | 1.373 (3) |
O1—C2 | 1.367 (3) | C3—H3 | 0.9300 |
N1—N2 | 1.384 (3) | C4—H4 | 0.9300 |
N1—C7 | 1.278 (3) | C6—H6 | 0.9300 |
O1—H1 | 0.8200 | C7—H7 | 0.9300 |
N2—C8 | 1.338 (3) | C9—H9A | 0.9600 |
N3—C8 | 1.324 (3) | C9—H9B | 0.9600 |
C1—C7 | 1.449 (3) | C9—H9C | 0.9600 |
C1—C2 | 1.405 (3) | C10—H10A | 0.9600 |
C1—C6 | 1.404 (3) | C10—H10B | 0.9600 |
C2—C3 | 1.385 (3) | C10—H10C | 0.9600 |
N2—H2 | 0.8600 | ||
C9—S2—C10 | 97.89 (14) | S1—C8—N2 | 118.69 (16) |
O2—S2—C9 | 105.88 (12) | N2—C8—N3 | 118.41 (19) |
O2—S2—C10 | 105.84 (12) | S1—C8—N3 | 122.90 (18) |
N2—N1—C7 | 114.45 (19) | C2—C3—H3 | 120.00 |
C2—O1—H1 | 110.00 | C4—C3—H3 | 120.00 |
N1—N2—C8 | 119.44 (18) | C5—C4—H4 | 120.00 |
C2—C1—C7 | 119.58 (19) | C3—C4—H4 | 120.00 |
C2—C1—C6 | 118.62 (19) | C1—C6—H6 | 120.00 |
C6—C1—C7 | 121.8 (2) | C5—C6—H6 | 120.00 |
O1—C2—C3 | 122.0 (2) | N1—C7—H7 | 119.00 |
C1—C2—C3 | 120.5 (2) | C1—C7—H7 | 119.00 |
N1—N2—H2 | 120.00 | S2—C9—H9A | 109.00 |
C8—N2—H2 | 120.00 | S2—C9—H9B | 110.00 |
O1—C2—C1 | 117.53 (18) | S2—C9—H9C | 109.00 |
H3A—N3—H3B | 120.00 | H9A—C9—H9B | 109.00 |
C2—C3—C4 | 120.3 (2) | H9A—C9—H9C | 109.00 |
C8—N3—H3B | 120.00 | H9B—C9—H9C | 109.00 |
C8—N3—H3A | 120.00 | S2—C10—H10A | 109.00 |
C3—C4—C5 | 119.3 (2) | S2—C10—H10B | 109.00 |
Br1—C5—C6 | 119.57 (17) | S2—C10—H10C | 109.00 |
Br1—C5—C4 | 118.85 (17) | H10A—C10—H10B | 109.00 |
C4—C5—C6 | 121.6 (2) | H10A—C10—H10C | 109.00 |
C1—C6—C5 | 119.8 (2) | H10B—C10—H10C | 109.00 |
N1—C7—C1 | 121.2 (2) | ||
C7—N1—N2—C8 | 178.2 (2) | C2—C1—C7—N1 | 169.6 (2) |
N2—N1—C7—C1 | 178.29 (19) | C6—C1—C7—N1 | −10.9 (3) |
N1—N2—C8—S1 | 178.26 (15) | O1—C2—C3—C4 | −178.3 (2) |
N1—N2—C8—N3 | −1.7 (3) | C1—C2—C3—C4 | 1.9 (3) |
C6—C1—C2—O1 | 178.65 (19) | C2—C3—C4—C5 | −0.7 (4) |
C6—C1—C2—C3 | −1.5 (3) | C3—C4—C5—Br1 | −179.52 (18) |
C7—C1—C2—O1 | −1.9 (3) | C3—C4—C5—C6 | −1.0 (4) |
C7—C1—C2—C3 | 178.0 (2) | Br1—C5—C6—C1 | 179.90 (16) |
C2—C1—C6—C5 | −0.1 (3) | C4—C5—C6—C1 | 1.4 (3) |
C7—C1—C6—C5 | −179.6 (2) |
D—H···A | D—H | H···A | D···A | D—H···A |
O1—H1···S1i | 0.82 | 2.40 | 3.1655 (17) | 157 |
N2—H2···O2ii | 0.86 | 2.10 | 2.897 (2) | 155 |
N3—H3A···O1iii | 0.86 | 2.37 | 3.048 (2) | 136 |
N3—H3A···N1 | 0.86 | 2.30 | 2.648 (3) | 104 |
N3—H3B···O2iv | 0.86 | 2.11 | 2.930 (3) | 160 |
C7—H7···O1 | 0.93 | 2.44 | 2.752 (3) | 100 |
C7—H7···O2ii | 0.93 | 2.53 | 3.315 (3) | 142 |
Symmetry codes: (i) x−1, y+1, z; (ii) x+1, y, z; (iii) x, y−1, z; (iv) x+1, y−1, z. |
Funding information
KB and PS thank the Department of Science and Technology (DST–SERB), grant No. SB/FT/CS-058/2013, New Delhi, India, for financial support.
References
Al-Karawi, A. J. M., Clegg, W., Harrington, R. S. & Henderson, R. A. (2009). Dalton Trans. pp. 564–570. Google Scholar
Altomare, A., Cascarano, G., Giacovazzo, C. & Guagliardi, A. (1993). J. Appl. Cryst. 26, 343–350. CrossRef Web of Science IUCr Journals Google Scholar
Beraldo, H. & Gambino, D. (2004). Mini Rev. Med. Chem. 4, 31–39. Web of Science CrossRef PubMed CAS Google Scholar
Bruker (2004). SAINT, APEX2, XPREP and SADABS. Bruker AXS Inc., Madison, Wisconsin, USA. Google Scholar
Chattopadhyay, D., Mazumdar, S. K., Banerjee, T., Ghosh, S. & Mak, T. C. W. (1988). Acta Cryst. C44, 1025–1028. CSD CrossRef CAS Web of Science IUCr Journals Google Scholar
Groom, C. R., Bruno, I. J., Lightfoot, M. P. & Ward, S. C. (2016). Acta Cryst. B72, 171–179. Web of Science CSD CrossRef IUCr Journals Google Scholar
Kargar, H., Kia, R., Akkurt, M. & Büyükgüngör, O. (2010a). Acta Cryst. E66, o2999. Web of Science CSD CrossRef IUCr Journals Google Scholar
Kargar, H., Kia, R., Akkurt, M. & Büyükgüngör, O. (2010b). Acta Cryst. E66, o2981. Web of Science CSD CrossRef IUCr Journals Google Scholar
Macrae, C. F., Bruno, I. J., Chisholm, J. A., Edgington, P. R., McCabe, P., Pidcock, E., Rodriguez-Monge, L., Taylor, R., van de Streek, J. & Wood, P. A. (2008). J. Appl. Cryst. 41, 466–470. Web of Science CSD CrossRef CAS IUCr Journals Google Scholar
McKinnon, J. J., Jayatilaka, D. & Spackman, M. A. (2007). Chem. Commun. pp. 3814–3816. Web of Science CrossRef Google Scholar
Monfared, H. H., Chamayou, A.-C., Khajeh, S. & Janiak, C. (2010). CrystEngComm, 12, 3526–2530. Web of Science CSD CrossRef CAS Google Scholar
Novaković, S. B., Fraisse, B., Bogdanović, G. A. & Spasojević-de Biré, A. (2007). Cryst. Growth Des. 7, 191–195. Google Scholar
Scovill, J. P., Klayman, D. L. & Franchino, D. G. (1982). J. Med. Chem. 25, 1261–1264. CrossRef CAS PubMed Web of Science Google Scholar
Sheldrick, G. M. (2015). Acta Cryst. C71, 3–8. Web of Science CrossRef IUCr Journals Google Scholar
Sivajeyanthi, P., Jeevaraj, M., Balasubramani, K., Viswanathan, V. & Velmurugan, D. (2017). Chemical Data Collections, 11–12, 220-231. CSD CrossRef Google Scholar
Spackman, M. A. & Jayatilaka, D. (2009). CrystEngComm, 11, 19–32. Web of Science CrossRef CAS Google Scholar
Spek, A. L. (2009). Acta Cryst. D65, 148–155. Web of Science CrossRef CAS IUCr Journals Google Scholar
Sriram, D., Yogeeswari, P., Thirumurugan, R. & Pavana, R. K. (2006). J. Med. Chem. 49, 3448–3450. Web of Science CrossRef PubMed CAS Google Scholar
Sun, Y., Fu, S., Zhang, J., Wang, X. & Wang, D. (2009). Acta Cryst. E65, o237. Web of Science CSD CrossRef IUCr Journals Google Scholar
Tidwell, T. T. (2008). Angew. Chem. Int. Ed. 47, 1016–1020. Web of Science CrossRef CAS Google Scholar
Westrip, S. P. (2010). J. Appl. Cryst. 43, 920–925. Web of Science CrossRef CAS IUCr Journals Google Scholar
Yıldız, M., Ünver, H., Erdener, D., Kiraz, A. & İskeleli, N. O. (2009). J. Mol. Struct. 919, 227–234. Google Scholar
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