organic compounds\(\def\hfill{\hskip 5em}\def\hfil{\hskip 3em}\def\eqno#1{\hfil {#1}}\)

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ISSN: 2056-9890

1-(5-Chloro-6-fluoro-1,3-benzo­thia­zol-2-yl)hydrazine

aX-ray Crystallography Unit, School of Physics, Universiti Sains Malaysia, 11800 USM, Penang, Malaysia, bDepartment of Chemistry, P. A. College of Engineering, Nadupadavu, Mangalore 574 153, India, and cDepartment of Chemistry, Mangalore University, Mangalagangotri 574 199, Mangalore, India
*Correspondence e-mail: hkfun@usm.my

(Received 4 July 2012; accepted 11 July 2012; online 18 July 2012)

In the title compound, C7H5ClFN3S, the 1,3-benzothia­zole ring system is nearly planar (r.m.s. deviation = 0.023 Å). In the crystal, mol­ecules are linked via inter­molecular N—H⋯N hydrogen bonds into a two-dimensional network parallel to (100).

Related literature

For general background to and the biological activities of benzothia­zole derivatives, see: Yaseen et al. (2006[Yaseen, A., Haitham, A. S., Houssain, A. S. & Najim, A. (2006). Z. Naturforsch. Teil B, 62 523-528.]); Kini et al. (2007[Kini, S., Swain, S. P. & Gandhi, A. M. (2007). Indian J. Pharm. Sci. 69, 46-50.]); Munirajasekhar et al. (2011[Munirajasekhar, D., Himaja, M. & Sunil, V. M. (2011). Int. Res. J. Pharm. 2, 114-117.]); Gurupadayya et al. (2008[Gurupadayya, B. M., Gopal, M., Padmashali, B. & Manohara, Y. N. (2008). Indian J. Pharm. Sci. 70, 572-577.]); Bowyer et al. (2007[Bowyer, P. W., Ruwani, S. & Gunaratne (2007). Biochem J. 2, 173-180.]); Mittal et al. (2007[Mittal, S., Samottra, M. K., Kaur & Gita, S. (2007). Phosphorus Sulfur Silicon Relat. Elem. 9, 2105-2113.]); Pozas et al. (2005[Pozas, R., Carballo, J., Castro, C. & Rubio, J. (2005). Bioorg. Med. Chem. Lett. 15, 1417-1421.]); Rana et al. (2008[Rana, A., Siddiqui, N. & Khan, S. (2008). Eur. J. Med. Chem. 43, 1114-1122.]). For a related structure, see: Fun et al. (2012[Fun, H.-K., Quah, C. K., Munirajasekhar, D., Himaja, M. & Sarojini, B. K. (2012). Acta Cryst. E68, o2438-o2439.]). For standard bond-length data, see: Allen et al. (1987[Allen, F. H., Kennard, O., Watson, D. G., Brammer, L., Orpen, A. G. & Taylor, R. (1987). J. Chem. Soc. Perkin Trans. 2, pp. S1-19.]). For the stability of the temperature controller used for the data collection, see: Cosier & Glazer (1986[Cosier, J. & Glazer, A. M. (1986). J. Appl. Cryst. 19, 105-107.]).

[Scheme 1]

Experimental

Crystal data
  • C7H5ClFN3S

  • Mr = 217.65

  • Monoclinic, P 21 /c

  • a = 11.1287 (6) Å

  • b = 5.6641 (3) Å

  • c = 13.3419 (7) Å

  • β = 108.552 (1)°

  • V = 797.29 (7) Å3

  • Z = 4

  • Mo Kα radiation

  • μ = 0.70 mm−1

  • T = 100 K

  • 0.31 × 0.16 × 0.14 mm

Data collection
  • Bruker SMART APEXII DUO CCD area-detector diffractometer

  • Absorption correction: multi-scan (SADABS; Bruker, 2009[Bruker (2009). APEX2, SAINT and SADABS. Bruker AXS Inc., Madison, Wisconsin, USA.]) Tmin = 0.813, Tmax = 0.908

  • 9459 measured reflections

  • 2899 independent reflections

  • 2638 reflections with I > 2σ(I)

  • Rint = 0.017

Refinement
  • R[F2 > 2σ(F2)] = 0.024

  • wR(F2) = 0.066

  • S = 1.07

  • 2899 reflections

  • 138 parameters

  • All H-atom parameters refined

  • Δρmax = 0.53 e Å−3

  • Δρmin = −0.20 e Å−3

Table 1
Hydrogen-bond geometry (Å, °)

D—H⋯A D—H H⋯A DA D—H⋯A
N2—H1N2⋯N1i 0.816 (16) 2.132 (16) 2.9478 (12) 176.9 (16)
N3—H2N3⋯N3ii 0.850 (16) 2.443 (17) 3.1382 (12) 139.5 (14)
Symmetry codes: (i) -x, -y, -z; (ii) [-x, y-{\script{1\over 2}}, -z+{\script{1\over 2}}].

Data collection: APEX2 (Bruker, 2009[Bruker (2009). APEX2, SAINT and SADABS. Bruker AXS Inc., Madison, Wisconsin, USA.]); cell refinement: SAINT (Bruker, 2009[Bruker (2009). APEX2, SAINT and SADABS. Bruker AXS Inc., Madison, Wisconsin, USA.]); data reduction: SAINT; program(s) used to solve structure: SHELXTL (Sheldrick, 2008[Sheldrick, G. M. (2008). Acta Cryst. A64, 112-122.]); program(s) used to refine structure: SHELXTL; molecular graphics: SHELXTL; software used to prepare material for publication: SHELXTL and PLATON (Spek, 2009[Spek, A. L. (2009). Acta Cryst. D65, 148-155.]).

Supporting information


Comment top

Benzothiazoles are very important bicyclic ring compounds which are of great interest because of their biological activities. The substituted benzothiazole derivatives have emerged as significant components in various diversified therapeutic applications. A literature review reveals that benzothiazoles and their derivatives show considerable activity, including potent inhibition of human immunodeficiency virus type 1 (HIV-1) replication by HIV-1 protease inhibition (Yaseen et al., 2006), antitumor (Kini et al., 2007), anthelmintic (Munirajasekhar et al., 2011), analgesic and anti-inflammatory (Gurupadayya et al., 2008), antimalarial (Bowyer et al., 2007), antifungal (Mittal et al., 2007), anticandidal activities (Pozas et al., 2005) and various activities relating to the central nervous system (Rana et al., 2008).

In the title molecule (Fig. 1), the benzo[d]thiazol-2-yl ring system (S1/N1/C1–C7) is nearly planar (r.m.s. deviation = 0.023). Bond lengths (Allen et al., 1987) and angles are within normal ranges and are comparable with a related structure (Fun et al., 2012).

In the crystal structure, Fig. 2, molecules are linked via intermolecular N2—H1N2···N1 and N3—H2N3···N3 hydrogen bonds (Table 1) into two-dimensional networks parallel to (100).

Related literature top

For general background to and the biological activities of benzothiazole derivatives, see: Yaseen et al., 2006; Kini et al., 2007; Munirajasekhar et al., 2011; Gurupadayya et al., 2008; Bowyer et al., 2007; Mittal et al., 2007; Pozas et al., 2005; Rana et al., 2008. For a related structure, see: Fun et al. (2012). For standard bond-length data, see: Allen et al. (1987). For the stability of the temperature controller used for the data collection, see: Cosier & Glazer (1986).

Experimental top

Concentrated HCl (6 ml) was added drop-wise to hydrazine hydrate [6 ml, 0.12 mol] at 273–283 K followed by ethylene glycol (50 ml). To the above solution, 5-chloro-6-fluoro benzothiazol-2-amine [6.079 g, 0.03 mol] was added in portions. It was then refluxed for 3–4 h. A colourless solid was precipitated at the end of the reflux period. The mixture was cooled and the product was filtered and then washed with water several times. It was air dried and recrystallized using ethanol. The single crystals were grown by slow evaporation from solvent methanol (m.p. = 483–485 K).

Refinement top

All hydrogen atoms were located in a difference Fourier map and refined freely with N—H = 0.815 (16)–0.905 (15) Å and C—H = 0.951 (14) or 0.966 (15) Å.

Structure description top

Benzothiazoles are very important bicyclic ring compounds which are of great interest because of their biological activities. The substituted benzothiazole derivatives have emerged as significant components in various diversified therapeutic applications. A literature review reveals that benzothiazoles and their derivatives show considerable activity, including potent inhibition of human immunodeficiency virus type 1 (HIV-1) replication by HIV-1 protease inhibition (Yaseen et al., 2006), antitumor (Kini et al., 2007), anthelmintic (Munirajasekhar et al., 2011), analgesic and anti-inflammatory (Gurupadayya et al., 2008), antimalarial (Bowyer et al., 2007), antifungal (Mittal et al., 2007), anticandidal activities (Pozas et al., 2005) and various activities relating to the central nervous system (Rana et al., 2008).

In the title molecule (Fig. 1), the benzo[d]thiazol-2-yl ring system (S1/N1/C1–C7) is nearly planar (r.m.s. deviation = 0.023). Bond lengths (Allen et al., 1987) and angles are within normal ranges and are comparable with a related structure (Fun et al., 2012).

In the crystal structure, Fig. 2, molecules are linked via intermolecular N2—H1N2···N1 and N3—H2N3···N3 hydrogen bonds (Table 1) into two-dimensional networks parallel to (100).

For general background to and the biological activities of benzothiazole derivatives, see: Yaseen et al., 2006; Kini et al., 2007; Munirajasekhar et al., 2011; Gurupadayya et al., 2008; Bowyer et al., 2007; Mittal et al., 2007; Pozas et al., 2005; Rana et al., 2008. For a related structure, see: Fun et al. (2012). For standard bond-length data, see: Allen et al. (1987). For the stability of the temperature controller used for the data collection, see: Cosier & Glazer (1986).

Computing details top

Data collection: APEX2 (Bruker, 2009); cell refinement: SAINT (Bruker, 2009); data reduction: SAINT (Bruker, 2009); program(s) used to solve structure: SHELXTL (Sheldrick, 2008); program(s) used to refine structure: SHELXTL (Sheldrick, 2008); molecular graphics: SHELXTL (Sheldrick, 2008); software used to prepare material for publication: SHELXTL (Sheldrick, 2008) and PLATON (Spek, 2009).

Figures top
[Figure 1] Fig. 1. The molecular structure of the title compound showing 50% probability displacement ellipsoids for non-H atoms.
[Figure 2] Fig. 2. The crystal structure of the title compound, viewed along the b axis. H atoms not involved in hydrogen bonds (dashed lines) have been omitted for clarity.
1-(5-Chloro-6-fluoro-1,3-benzothiazol-2-yl)hydrazine top
Crystal data top
C7H5ClFN3SF(000) = 440
Mr = 217.65Dx = 1.813 Mg m3
Monoclinic, P21/cMo Kα radiation, λ = 0.71073 Å
Hall symbol: -P 2ybcCell parameters from 5638 reflections
a = 11.1287 (6) Åθ = 3.9–32.6°
b = 5.6641 (3) ŵ = 0.70 mm1
c = 13.3419 (7) ÅT = 100 K
β = 108.552 (1)°Block, colourless
V = 797.29 (7) Å30.31 × 0.16 × 0.14 mm
Z = 4
Data collection top
Bruker SMART APEXII DUO CCD area-detector
diffractometer
2899 independent reflections
Radiation source: fine-focus sealed tube2638 reflections with I > 2σ(I)
Graphite monochromatorRint = 0.017
φ and ω scansθmax = 32.7°, θmin = 1.9°
Absorption correction: multi-scan
(SADABS; Bruker, 2009)
h = 1616
Tmin = 0.813, Tmax = 0.908k = 88
9459 measured reflectionsl = 2020
Refinement top
Refinement on F2Primary atom site location: structure-invariant direct methods
Least-squares matrix: fullSecondary atom site location: difference Fourier map
R[F2 > 2σ(F2)] = 0.024Hydrogen site location: inferred from neighbouring sites
wR(F2) = 0.066All H-atom parameters refined
S = 1.07 w = 1/[σ2(Fo2) + (0.0319P)2 + 0.296P]
where P = (Fo2 + 2Fc2)/3
2899 reflections(Δ/σ)max = 0.001
138 parametersΔρmax = 0.53 e Å3
0 restraintsΔρmin = 0.20 e Å3
Crystal data top
C7H5ClFN3SV = 797.29 (7) Å3
Mr = 217.65Z = 4
Monoclinic, P21/cMo Kα radiation
a = 11.1287 (6) ŵ = 0.70 mm1
b = 5.6641 (3) ÅT = 100 K
c = 13.3419 (7) Å0.31 × 0.16 × 0.14 mm
β = 108.552 (1)°
Data collection top
Bruker SMART APEXII DUO CCD area-detector
diffractometer
2899 independent reflections
Absorption correction: multi-scan
(SADABS; Bruker, 2009)
2638 reflections with I > 2σ(I)
Tmin = 0.813, Tmax = 0.908Rint = 0.017
9459 measured reflections
Refinement top
R[F2 > 2σ(F2)] = 0.0240 restraints
wR(F2) = 0.066All H-atom parameters refined
S = 1.07Δρmax = 0.53 e Å3
2899 reflectionsΔρmin = 0.20 e Å3
138 parameters
Special details top

Experimental. The crystal was placed in the cold stream of an Oxford Cryosystems Cobra open-flow nitrogen cryostat (Cosier & Glazer, 1986) operating at 100.0 (1) K.

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.

Fractional atomic coordinates and isotropic or equivalent isotropic displacement parameters (Å2) top
xyzUiso*/Ueq
S10.17661 (2)0.55946 (4)0.127235 (17)0.01252 (6)
F10.45495 (6)0.83076 (11)0.09724 (5)0.01932 (13)
Cl10.40693 (2)0.42019 (4)0.236217 (18)0.01702 (6)
N10.13780 (7)0.19036 (15)0.00140 (6)0.01316 (14)
N20.02947 (8)0.17861 (16)0.12535 (6)0.01531 (15)
N30.01178 (8)0.31566 (15)0.19707 (6)0.01435 (15)
C10.25396 (8)0.54873 (16)0.03242 (7)0.01196 (15)
C20.33315 (8)0.71802 (17)0.01037 (7)0.01342 (15)
C30.37807 (8)0.67098 (17)0.07310 (7)0.01365 (16)
C40.34704 (8)0.46473 (17)0.13335 (7)0.01302 (15)
C50.26897 (8)0.29589 (17)0.11025 (7)0.01283 (15)
C60.22136 (8)0.33884 (16)0.02676 (7)0.01158 (15)
C70.10783 (8)0.28418 (17)0.08008 (7)0.01228 (15)
H2A0.3595 (12)0.862 (3)0.0500 (11)0.014 (3)*
H5A0.2461 (12)0.158 (3)0.1530 (11)0.015 (3)*
H1N20.0159 (14)0.073 (3)0.0922 (12)0.023 (4)*
H1N30.0937 (14)0.360 (3)0.1679 (12)0.023 (4)*
H2N30.0068 (14)0.231 (3)0.2508 (12)0.025 (4)*
Atomic displacement parameters (Å2) top
U11U22U33U12U13U23
S10.01537 (10)0.01201 (11)0.01173 (10)0.00092 (7)0.00648 (7)0.00130 (7)
F10.0220 (3)0.0177 (3)0.0227 (3)0.0073 (2)0.0133 (2)0.0019 (2)
Cl10.01930 (11)0.01979 (12)0.01571 (10)0.00142 (8)0.01083 (8)0.00148 (8)
N10.0149 (3)0.0130 (3)0.0136 (3)0.0015 (3)0.0075 (3)0.0013 (3)
N20.0196 (4)0.0146 (4)0.0155 (3)0.0048 (3)0.0108 (3)0.0036 (3)
N30.0165 (3)0.0160 (4)0.0128 (3)0.0018 (3)0.0079 (3)0.0001 (3)
C10.0131 (3)0.0121 (4)0.0113 (3)0.0002 (3)0.0048 (3)0.0004 (3)
C20.0149 (4)0.0121 (4)0.0142 (4)0.0013 (3)0.0060 (3)0.0008 (3)
C30.0133 (3)0.0136 (4)0.0153 (4)0.0018 (3)0.0062 (3)0.0007 (3)
C40.0134 (3)0.0150 (4)0.0122 (3)0.0010 (3)0.0063 (3)0.0002 (3)
C50.0134 (3)0.0136 (4)0.0124 (3)0.0004 (3)0.0054 (3)0.0007 (3)
C60.0124 (3)0.0112 (4)0.0118 (3)0.0003 (3)0.0047 (3)0.0002 (3)
C70.0133 (3)0.0120 (4)0.0121 (3)0.0004 (3)0.0050 (3)0.0003 (3)
Geometric parameters (Å, º) top
S1—C11.7429 (9)N3—H2N30.849 (17)
S1—C71.7625 (10)C1—C21.3957 (13)
F1—C31.3529 (11)C1—C61.4093 (13)
Cl1—C41.7243 (9)C2—C31.3839 (12)
N1—C71.3109 (11)C2—H2A0.966 (15)
N1—C61.3912 (11)C3—C41.3977 (13)
N2—C71.3483 (11)C4—C51.3910 (13)
N2—N31.4172 (11)C5—C61.3986 (12)
N2—H1N20.815 (16)C5—H5A0.951 (14)
N3—H1N30.905 (15)
C1—S1—C788.21 (4)F1—C3—C4118.78 (8)
C7—N1—C6109.48 (8)C2—C3—C4122.51 (9)
C7—N2—N3117.01 (8)C5—C4—C3120.30 (8)
C7—N2—H1N2117.3 (11)C5—C4—Cl1120.18 (7)
N3—N2—H1N2119.3 (11)C3—C4—Cl1119.52 (7)
N2—N3—H1N3111.1 (10)C4—C5—C6118.59 (8)
N2—N3—H2N3108.3 (11)C4—C5—H5A119.8 (8)
H1N3—N3—H2N3107.7 (14)C6—C5—H5A121.5 (8)
C2—C1—C6121.92 (8)N1—C6—C5124.41 (8)
C2—C1—S1128.31 (7)N1—C6—C1115.70 (8)
C6—C1—S1109.73 (7)C5—C6—C1119.85 (8)
C3—C2—C1116.83 (9)N1—C7—N2122.99 (9)
C3—C2—H2A118.6 (8)N1—C7—S1116.89 (7)
C1—C2—H2A124.6 (8)N2—C7—S1120.11 (7)
F1—C3—C2118.72 (8)
C7—S1—C1—C2177.55 (9)C7—N1—C6—C10.18 (11)
C7—S1—C1—C60.05 (7)C4—C5—C6—N1176.84 (8)
C6—C1—C2—C30.32 (13)C4—C5—C6—C10.63 (13)
S1—C1—C2—C3176.91 (7)C2—C1—C6—N1177.63 (8)
C1—C2—C3—F1179.88 (8)S1—C1—C6—N10.06 (10)
C1—C2—C3—C40.13 (14)C2—C1—C6—C50.06 (14)
F1—C3—C4—C5179.54 (8)S1—C1—C6—C5177.75 (7)
C2—C3—C4—C50.45 (14)C6—N1—C7—N2179.09 (8)
F1—C3—C4—Cl10.12 (12)C6—N1—C7—S10.22 (10)
C2—C3—C4—Cl1179.89 (7)N3—N2—C7—N1169.63 (8)
C3—C4—C5—C60.82 (13)N3—N2—C7—S111.09 (11)
Cl1—C4—C5—C6179.52 (7)C1—S1—C7—N10.16 (8)
C7—N1—C6—C5177.75 (8)C1—S1—C7—N2179.17 (8)
Hydrogen-bond geometry (Å, º) top
D—H···AD—HH···AD···AD—H···A
N2—H1N2···N1i0.816 (16)2.132 (16)2.9478 (12)176.9 (16)
N3—H2N3···N3ii0.850 (16)2.443 (17)3.1382 (12)139.5 (14)
Symmetry codes: (i) x, y, z; (ii) x, y1/2, z+1/2.

Experimental details

Crystal data
Chemical formulaC7H5ClFN3S
Mr217.65
Crystal system, space groupMonoclinic, P21/c
Temperature (K)100
a, b, c (Å)11.1287 (6), 5.6641 (3), 13.3419 (7)
β (°) 108.552 (1)
V3)797.29 (7)
Z4
Radiation typeMo Kα
µ (mm1)0.70
Crystal size (mm)0.31 × 0.16 × 0.14
Data collection
DiffractometerBruker SMART APEXII DUO CCD area-detector
Absorption correctionMulti-scan
(SADABS; Bruker, 2009)
Tmin, Tmax0.813, 0.908
No. of measured, independent and
observed [I > 2σ(I)] reflections
9459, 2899, 2638
Rint0.017
(sin θ/λ)max1)0.759
Refinement
R[F2 > 2σ(F2)], wR(F2), S 0.024, 0.066, 1.07
No. of reflections2899
No. of parameters138
H-atom treatmentAll H-atom parameters refined
Δρmax, Δρmin (e Å3)0.53, 0.20

Computer programs: APEX2 (Bruker, 2009), SAINT (Bruker, 2009), SHELXTL (Sheldrick, 2008) and PLATON (Spek, 2009).

Hydrogen-bond geometry (Å, º) top
D—H···AD—HH···AD···AD—H···A
N2—H1N2···N1i0.816 (16)2.132 (16)2.9478 (12)176.9 (16)
N3—H2N3···N3ii0.850 (16)2.443 (17)3.1382 (12)139.5 (14)
Symmetry codes: (i) x, y, z; (ii) x, y1/2, z+1/2.
 

Footnotes

Thomson Reuters ResearcherID: A-3561-2009.

§Thomson Reuters ResearcherID: A-5525-2009.

Acknowledgements

The authors thank Universiti Sains Malaysia (USM) for a Research University Grant (No. 1001/PFIZIK/811160). BKS gratefully acknowledges the Department of Atomic Energy (DAE)/BRNS, Government of India, for providing financial assistance in the BRNS Project (No. 2011/34/20-BRNS/0846).

References

First citationAllen, F. H., Kennard, O., Watson, D. G., Brammer, L., Orpen, A. G. & Taylor, R. (1987). J. Chem. Soc. Perkin Trans. 2, pp. S1–19.  CSD CrossRef Web of Science Google Scholar
First citationBowyer, P. W., Ruwani, S. & Gunaratne (2007). Biochem J. 2, 173–180.  Google Scholar
First citationBruker (2009). APEX2, SAINT and SADABS. Bruker AXS Inc., Madison, Wisconsin, USA.  Google Scholar
First citationCosier, J. & Glazer, A. M. (1986). J. Appl. Cryst. 19, 105–107.  CrossRef CAS Web of Science IUCr Journals Google Scholar
First citationFun, H.-K., Quah, C. K., Munirajasekhar, D., Himaja, M. & Sarojini, B. K. (2012). Acta Cryst. E68, o2438–o2439.  CSD CrossRef IUCr Journals Google Scholar
First citationGurupadayya, B. M., Gopal, M., Padmashali, B. & Manohara, Y. N. (2008). Indian J. Pharm. Sci. 70, 572–577.  Web of Science CAS PubMed Google Scholar
First citationKini, S., Swain, S. P. & Gandhi, A. M. (2007). Indian J. Pharm. Sci. 69, 46–50.  CrossRef CAS Google Scholar
First citationMittal, S., Samottra, M. K., Kaur & Gita, S. (2007). Phosphorus Sulfur Silicon Relat. Elem. 9, 2105–2113.  Google Scholar
First citationMunirajasekhar, D., Himaja, M. & Sunil, V. M. (2011). Int. Res. J. Pharm. 2, 114–117.  CAS Google Scholar
First citationPozas, R., Carballo, J., Castro, C. & Rubio, J. (2005). Bioorg. Med. Chem. Lett. 15, 1417–1421.  Web of Science CrossRef PubMed CAS Google Scholar
First citationRana, A., Siddiqui, N. & Khan, S. (2008). Eur. J. Med. Chem. 43, 1114–1122.  Web of Science CrossRef PubMed CAS Google Scholar
First citationSheldrick, G. M. (2008). Acta Cryst. A64, 112–122.  Web of Science CrossRef CAS IUCr Journals Google Scholar
First citationSpek, A. L. (2009). Acta Cryst. D65, 148–155.  Web of Science CrossRef CAS IUCr Journals Google Scholar
First citationYaseen, A., Haitham, A. S., Houssain, A. S. & Najim, A. (2006). Z. Naturforsch. Teil B, 62 523–528.  Google Scholar

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