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

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ISSN: 2056-9890

N-(4-Chloro­benzyl­­idene)-3,4-di­methyl­isoxazol-5-amine

aThe Center of Excellence for Advanced Materials Research, King Abdul Aziz University, Jeddah 21589, PO Box 80203, Saudi Arabia, bDepartment of Chemistry, Faculty of Science, King Abdul Aziz University, Jeddah 21589, PO Box 80203, Saudi Arabia, and cDepartment of Physics, University of Sargodha, Sargodha, Pakistan
*Correspondence e-mail: dmntahir_uos@yahoo.com

(Received 18 July 2010; accepted 22 July 2010; online 31 July 2010)

The mol­ecule of the title compound, C12H11ClN2O, has E configuration at the azomethine double bond and is virtually planar with a dihedral angle of 1.25 (13)° between the benzene and isoxazole rings. C—H⋯π inter­actions stabilize the crystal structure.

Related literature

For related structures, see: Asiri et al. (2010a[Asiri, A. M., Khan, S. A. & Tahir, M. N. (2010a). Acta Cryst. E66, o2077.],b[Asiri, A. M., Khan, S. A., Tan, K. W. & Ng, S. W. (2010b). Acta Cryst. E66, o1783.]); Fun et al. (2010a[Fun, H.-K., Hemamalini, M., Asiri, A. M. & Khan, S. A. (2010a). Acta Cryst. E66, o1037-o1038.],b[Fun, H.-K., Hemamalini, M., Asiri, A. M., Khan, S. A. & Khan, K. A. (2010b). Acta Cryst. E66, o773-o774.]); Shad et al. (2008[Shad, H. A., Chohan, Z. H., Tahir, M. N. & Khan, I. U. (2008). Acta Cryst. E64, o635.]); Tahir et al. (2008[Tahir, M. N., Chohan, Z. H., Shad, H. A. & Khan, I. U. (2008). Acta Cryst. E64, o720.]). For graph-set notation, see: Bernstein et al. (1995[Bernstein, J., Davis, R. E., Shimoni, L. & Chang, N.-L. (1995). Angew. Chem. Int. Ed. Engl. 34, 1555-1573.]).

[Scheme 1]

Experimental

Crystal data
  • C12H11ClN2O

  • Mr = 234.68

  • Monoclinic, P 21 /n

  • a = 5.0877 (2) Å

  • b = 24.5197 (9) Å

  • c = 9.4673 (4) Å

  • β = 94.871 (2)°

  • V = 1176.77 (8) Å3

  • Z = 4

  • Mo Kα radiation

  • μ = 0.30 mm−1

  • T = 296 K

  • 0.30 × 0.16 × 0.14 mm

Data collection
  • Bruker Kappa APEXII CCD diffractometer

  • Absorption correction: multi-scan (SADABS; Bruker, 2005[Bruker (2005). SADABS. Bruker AXS Inc., Madison, Wisconsin, USA.]) Tmin = 0.868, Tmax = 0.965

  • 9016 measured reflections

  • 2112 independent reflections

  • 1539 reflections with I > 2σ(I)

  • Rint = 0.030

Refinement
  • R[F2 > 2σ(F2)] = 0.044

  • wR(F2) = 0.120

  • S = 1.07

  • 2112 reflections

  • 147 parameters

  • H-atom parameters constrained

  • Δρmax = 0.15 e Å−3

  • Δρmin = −0.14 e Å−3

Table 1
Hydrogen-bond geometry (Å, °)

Cg1 is the centroid of the O1/N2/C10/C9/C8 ring.

D—H⋯A D—H H⋯A DA D—H⋯A
C11—H11CCg1i 0.96 2.91 3.644 (2) 134
Symmetry code: (i) x+1, y, z.

Data collection: APEX2 (Bruker, 2009[Bruker (2009). APEX2 and SAINT. Bruker AXS Inc., Madison, Wisconsin, USA.]); cell refinement: SAINT (Bruker, 2009[Bruker (2009). APEX2 and SAINT. Bruker AXS Inc., Madison, Wisconsin, USA.]); data reduction: SAINT; program(s) used to solve structure: SHELXS97 (Sheldrick, 2008[Sheldrick, G. M. (2008). Acta Cryst. A64, 112-122.]); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008[Sheldrick, G. M. (2008). Acta Cryst. A64, 112-122.]); molecular graphics: ORTEP-3 for Windows (Farrugia, 1997[Farrugia, L. J. (1997). J. Appl. Cryst. 30, 565.]) and PLATON (Spek, 2009[Spek, A. L. (2009). Acta Cryst. D65, 148-155.]); software used to prepare material for publication: WinGX (Farrugia, 1999[Farrugia, L. J. (1999). J. Appl. Cryst. 32, 837-838.]) and PLATON.

Supporting information


Comment top

The title compound (Fig. 1) has been prepared in continuation of our work on the synthesis of Schiff bases of 3,4-dimethyisoxazol-5-amine. We have recently reported the crystal structure of N-(4-bromobenzylidene)-3,4-dimethylisoxazol-5-amine (Asiri et al., 2010a), which is isostructural with the title compound.

The crystal structures of 4-chloro-2- [(E)-({4-[N-(3,4-dimethylisoxazol-5-yl)sulfamoyl]phenyl}iminio) methyl]phenolate (Shad et al., 2008), 4-bromo-2-((E)-{4-[(3,4-dimethylisoxazol-5-yl)sulfamoyl]phenyl} iminiomethyl)phenolate (Tahir et al., 2008), 2-[(E)-(3,4-dimethylisoxazol-5-yl)iminomethyl]phenol (Fun et al., 2010a), 1-[(E)-(3,4-dimethylisoxazol-5-yl)iminomethyl]-2-naphthol (Fun et al., 2010b) and N-[4-(dimethylamino)benzylidene]-3,4-dimethylisoxazol-5-amine (Asiri et al., 2010b) have also been published previously, which contain the 5-amino-3,4-dimethylisoxazole moiety.

In the title compound, the 4-chlorobenzylidene moiety A (C1—C7/CL1) and 5-amino-3,4-dimethylisoxazole moiety B (N1/C8—C12/N2/O1) are planar with r. m. s. deviation of 0.0042 and 0.0076 Å, respectively. The dihedral angle between A/B is 1.10 (11)°. R. m. s. deviation from the plane of all non-hydrogen atoms in the molecule is 0.0200 Å, with the largest deviation of the CL1 atom [0.0534 (11) Å]. Weak intramolecular H-bonding of C—H···O type (Table 1, Fig. 1) exists and complete an S(5) ring motif (Bernstein et al., 1995). There exists no π···π interaction. The C—H···π interaction (Table 1) play an important role in stabilizing the molecules.

Related literature top

For related structures, see: Asiri et al. (2010a,b); Fun et al. (2010a,b); Shad et al. (2008); Tahir et al. (2008). For graph-set notation, see: Bernstein et al. (1995).

Experimental top

A mixture of 4-chlorobenzaldehyde (0.30 g, 2.2 mmol) and 5-amino-3,4-dimethylisoxazole (0.24 g, 2.2 mmol) in ethanol (15 ml) was refluxed for 5 h with stirring to give a light brown precipitate. This material was filtered off and washed with ethanol to give the pure Schiff base (m.p. 397 K; yield: 78.5%)

1H-NMR (CDCl3) δ: 9.97 (s, 1H, CHolefinic), 7.79 (d, H3, CHaromatic J = 5.4 Hz), 7.75 (dd, H4, CHaromatic, J = 8.4 Hz), 7.69 (dd, H5, CHaromatic J = 8.4 Hz), 7.61 (d, H6 CHaromatic, J = 4.8 Hz), 2.25 (s, N—CH3), 1.76 (s,-CH3).

Refinement top

The H-atoms were positioned geometrically (C–H = 0.93–0.96 Å) and refined as riding with Uiso(H) = xUeq(C), where x = 1.5 for methyl and x = 1.2 for other H-atoms.

Structure description top

The title compound (Fig. 1) has been prepared in continuation of our work on the synthesis of Schiff bases of 3,4-dimethyisoxazol-5-amine. We have recently reported the crystal structure of N-(4-bromobenzylidene)-3,4-dimethylisoxazol-5-amine (Asiri et al., 2010a), which is isostructural with the title compound.

The crystal structures of 4-chloro-2- [(E)-({4-[N-(3,4-dimethylisoxazol-5-yl)sulfamoyl]phenyl}iminio) methyl]phenolate (Shad et al., 2008), 4-bromo-2-((E)-{4-[(3,4-dimethylisoxazol-5-yl)sulfamoyl]phenyl} iminiomethyl)phenolate (Tahir et al., 2008), 2-[(E)-(3,4-dimethylisoxazol-5-yl)iminomethyl]phenol (Fun et al., 2010a), 1-[(E)-(3,4-dimethylisoxazol-5-yl)iminomethyl]-2-naphthol (Fun et al., 2010b) and N-[4-(dimethylamino)benzylidene]-3,4-dimethylisoxazol-5-amine (Asiri et al., 2010b) have also been published previously, which contain the 5-amino-3,4-dimethylisoxazole moiety.

In the title compound, the 4-chlorobenzylidene moiety A (C1—C7/CL1) and 5-amino-3,4-dimethylisoxazole moiety B (N1/C8—C12/N2/O1) are planar with r. m. s. deviation of 0.0042 and 0.0076 Å, respectively. The dihedral angle between A/B is 1.10 (11)°. R. m. s. deviation from the plane of all non-hydrogen atoms in the molecule is 0.0200 Å, with the largest deviation of the CL1 atom [0.0534 (11) Å]. Weak intramolecular H-bonding of C—H···O type (Table 1, Fig. 1) exists and complete an S(5) ring motif (Bernstein et al., 1995). There exists no π···π interaction. The C—H···π interaction (Table 1) play an important role in stabilizing the molecules.

For related structures, see: Asiri et al. (2010a,b); Fun et al. (2010a,b); Shad et al. (2008); Tahir et al. (2008). For graph-set notation, see: Bernstein et al. (1995).

Computing details top

Data collection: APEX2 (Bruker, 2009); cell refinement: SAINT (Bruker, 2009); data reduction: SAINT (Bruker, 2009); program(s) used to solve structure: SHELXS97 (Sheldrick, 2008); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008); molecular graphics: ORTEP-3 for Windows (Farrugia, 1997) and PLATON (Spek, 2009); software used to prepare material for publication: WinGX (Farrugia, 1999) and PLATON (Spek, 2009).

Figures top
[Figure 1] Fig. 1. View of the title compound with the atom numbering scheme. The displacement ellipsoids are drawn at the 50% probability level. H-atoms are shown as small spheres of arbitrary radii. The dotted line indicates the intramolecular hydrogen H-bond.
N-(4-Chlorobenzylidene)-3,4-dimethylisoxazol-5-amine top
Crystal data top
C12H11ClN2OF(000) = 488
Mr = 234.68Dx = 1.325 Mg m3
Monoclinic, P21/nMo Kα radiation, λ = 0.71073 Å
Hall symbol: -P 2ynCell parameters from 1539 reflections
a = 5.0877 (2) Åθ = 2.3–25.3°
b = 24.5197 (9) ŵ = 0.30 mm1
c = 9.4673 (4) ÅT = 296 K
β = 94.871 (2)°Needle, light brown
V = 1176.77 (8) Å30.30 × 0.16 × 0.14 mm
Z = 4
Data collection top
Bruker KAPPA APEXII CCD
diffractometer
2112 independent reflections
Radiation source: fine-focus sealed tube1539 reflections with I > 2σ(I)
Graphite monochromatorRint = 0.030
Detector resolution: 8.10 pixels mm-1θmax = 25.3°, θmin = 2.3°
ω scansh = 66
Absorption correction: multi-scan
(SADABS; Bruker, 2005)
k = 2929
Tmin = 0.868, Tmax = 0.965l = 1111
9016 measured reflections
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)] = 0.044Hydrogen site location: inferred from neighbouring sites
wR(F2) = 0.120H-atom parameters constrained
S = 1.07 w = 1/[σ2(Fo2) + (0.0521P)2 + 0.2476P]
where P = (Fo2 + 2Fc2)/3
2112 reflections(Δ/σ)max < 0.001
147 parametersΔρmax = 0.15 e Å3
0 restraintsΔρmin = 0.14 e Å3
Crystal data top
C12H11ClN2OV = 1176.77 (8) Å3
Mr = 234.68Z = 4
Monoclinic, P21/nMo Kα radiation
a = 5.0877 (2) ŵ = 0.30 mm1
b = 24.5197 (9) ÅT = 296 K
c = 9.4673 (4) Å0.30 × 0.16 × 0.14 mm
β = 94.871 (2)°
Data collection top
Bruker KAPPA APEXII CCD
diffractometer
2112 independent reflections
Absorption correction: multi-scan
(SADABS; Bruker, 2005)
1539 reflections with I > 2σ(I)
Tmin = 0.868, Tmax = 0.965Rint = 0.030
9016 measured reflections
Refinement top
R[F2 > 2σ(F2)] = 0.0440 restraints
wR(F2) = 0.120H-atom parameters constrained
S = 1.07Δρmax = 0.15 e Å3
2112 reflectionsΔρmin = 0.14 e Å3
147 parameters
Special details top

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 e.s.d.'s 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 > 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
xyzUiso*/Ueq
Cl10.59118 (13)0.19483 (3)0.44471 (7)0.0894 (3)
O10.5343 (3)0.03641 (6)0.15781 (16)0.0736 (6)
N10.3653 (3)0.11804 (7)0.05045 (17)0.0608 (6)
N20.7399 (4)0.02071 (8)0.2600 (2)0.0763 (7)
C10.0022 (4)0.11701 (8)0.1255 (2)0.0576 (7)
C20.1918 (4)0.08576 (9)0.2009 (2)0.0676 (8)
C30.3750 (4)0.10921 (9)0.2987 (2)0.0701 (8)
C40.3674 (4)0.16448 (9)0.3200 (2)0.0630 (8)
C50.1824 (5)0.19639 (9)0.2446 (3)0.0775 (9)
C60.0019 (4)0.17261 (10)0.1484 (3)0.0724 (8)
C70.1915 (4)0.09088 (9)0.0251 (2)0.0622 (7)
C80.5459 (4)0.09160 (9)0.1431 (2)0.0576 (7)
C90.7462 (4)0.11227 (8)0.2291 (2)0.0575 (7)
C100.8603 (4)0.06588 (9)0.2988 (2)0.0617 (7)
C111.0916 (4)0.06456 (11)0.4077 (2)0.0785 (9)
C120.8318 (4)0.16992 (9)0.2438 (3)0.0778 (9)
H20.196090.048320.185540.0811*
H30.501490.087840.349210.0842*
H50.180160.233910.258950.0930*
H60.122980.194250.097570.0869*
H70.188240.053130.015780.0746*
H11A1.153180.027720.420020.1177*
H11B1.039400.078210.496130.1177*
H11C1.230560.086920.376650.1177*
H12A0.720030.192300.180850.1168*
H12B1.010970.173120.220230.1168*
H12C0.819710.181680.339720.1168*
Atomic displacement parameters (Å2) top
U11U22U33U12U13U23
Cl10.0947 (5)0.0856 (5)0.0842 (4)0.0155 (3)0.0142 (3)0.0044 (3)
O10.0787 (10)0.0567 (9)0.0821 (10)0.0045 (7)0.0123 (8)0.0012 (7)
N10.0579 (10)0.0613 (11)0.0634 (10)0.0002 (8)0.0067 (8)0.0017 (8)
N20.0797 (12)0.0638 (12)0.0816 (12)0.0000 (10)0.0161 (10)0.0055 (10)
C10.0568 (11)0.0568 (12)0.0597 (11)0.0007 (9)0.0079 (9)0.0057 (9)
C20.0741 (14)0.0517 (12)0.0761 (14)0.0019 (10)0.0014 (11)0.0053 (11)
C30.0702 (14)0.0664 (14)0.0715 (14)0.0028 (11)0.0071 (11)0.0110 (11)
C40.0642 (13)0.0644 (14)0.0602 (12)0.0080 (10)0.0041 (10)0.0028 (10)
C50.0836 (16)0.0537 (13)0.0932 (17)0.0027 (11)0.0041 (13)0.0021 (12)
C60.0709 (14)0.0617 (14)0.0822 (15)0.0064 (11)0.0074 (11)0.0056 (12)
C70.0663 (13)0.0559 (12)0.0647 (12)0.0006 (10)0.0077 (10)0.0048 (10)
C80.0589 (12)0.0548 (12)0.0598 (11)0.0013 (9)0.0099 (9)0.0006 (9)
C90.0565 (11)0.0618 (13)0.0552 (11)0.0041 (10)0.0102 (9)0.0011 (10)
C100.0633 (12)0.0647 (13)0.0575 (11)0.0039 (11)0.0082 (9)0.0004 (10)
C110.0716 (14)0.0913 (18)0.0708 (14)0.0056 (12)0.0044 (11)0.0059 (12)
C120.0793 (15)0.0613 (14)0.0921 (16)0.0106 (12)0.0026 (12)0.0055 (12)
Geometric parameters (Å, º) top
Cl1—C41.737 (2)C9—C101.415 (3)
O1—N21.417 (2)C9—C121.482 (3)
O1—C81.362 (3)C10—C111.498 (3)
N1—C71.277 (3)C2—H20.9300
N1—C81.377 (3)C3—H30.9300
N2—C101.303 (3)C5—H50.9300
C1—C21.382 (3)C6—H60.9300
C1—C61.380 (3)C7—H70.9300
C1—C71.458 (3)C11—H11A0.9600
C2—C31.382 (3)C11—H11B0.9600
C3—C41.371 (3)C11—H11C0.9600
C4—C51.376 (3)C12—H12A0.9600
C5—C61.368 (4)C12—H12B0.9600
C8—C91.348 (3)C12—H12C0.9600
Cl1···H12Ci3.0600C12···H11C3.0700
O1···H72.3400H2···H72.4300
O1···H2ii2.7200H2···O1ii2.7200
N1···H62.5800H3···C11vi3.0200
N1···H12A2.7800H6···N12.5800
N1···H12Biii2.8500H7···O12.3400
C3···C7iii3.570 (3)H7···H22.4300
C7···C3iv3.570 (3)H11B···C3vii3.0800
C7···C9iii3.482 (3)H11C···C8iv2.8400
C9···C7iv3.482 (3)H11C···C123.0700
C3···H11Bi3.0800H12A···N12.7800
C8···H11Ciii2.8400H12B···N1iv2.8500
C11···H3v3.0200H12C···Cl1vii3.0600
N2—O1—C8107.69 (15)C1—C2—H2119.00
C7—N1—C8120.28 (18)C3—C2—H2119.00
O1—N2—C10105.29 (17)C2—C3—H3121.00
C2—C1—C6118.45 (19)C4—C3—H3121.00
C2—C1—C7119.77 (18)C4—C5—H5120.00
C6—C1—C7121.78 (19)C6—C5—H5120.00
C1—C2—C3121.1 (2)C1—C6—H6119.00
C2—C3—C4118.94 (19)C5—C6—H6119.00
Cl1—C4—C3119.90 (16)N1—C7—H7119.00
Cl1—C4—C5119.28 (18)C1—C7—H7119.00
C3—C4—C5120.82 (19)C10—C11—H11A109.00
C4—C5—C6119.6 (2)C10—C11—H11B109.00
C1—C6—C5121.1 (2)C10—C11—H11C109.00
N1—C7—C1122.3 (2)H11A—C11—H11B109.00
O1—C8—N1120.02 (18)H11A—C11—H11C109.00
O1—C8—C9110.42 (18)H11B—C11—H11C109.00
N1—C8—C9129.6 (2)C9—C12—H12A109.00
C8—C9—C10103.81 (18)C9—C12—H12B109.00
C8—C9—C12128.04 (19)C9—C12—H12C109.00
C10—C9—C12128.13 (19)H12A—C12—H12B109.00
N2—C10—C9112.79 (18)H12A—C12—H12C109.00
N2—C10—C11119.9 (2)H12B—C12—H12C110.00
C9—C10—C11127.3 (2)
C8—O1—N2—C100.4 (2)C1—C2—C3—C40.3 (3)
N2—O1—C8—N1179.39 (17)C2—C3—C4—Cl1178.75 (15)
N2—O1—C8—C90.1 (2)C2—C3—C4—C50.6 (3)
C8—N1—C7—C1179.45 (18)Cl1—C4—C5—C6178.59 (19)
C7—N1—C8—O12.1 (3)C3—C4—C5—C60.8 (4)
C7—N1—C8—C9178.5 (2)C4—C5—C6—C10.0 (4)
O1—N2—C10—C90.5 (2)O1—C8—C9—C100.2 (2)
O1—N2—C10—C11179.91 (17)O1—C8—C9—C12178.5 (2)
C6—C1—C2—C31.0 (3)N1—C8—C9—C10179.6 (2)
C7—C1—C2—C3178.80 (18)N1—C8—C9—C122.1 (4)
C2—C1—C6—C50.8 (3)C8—C9—C10—N20.4 (2)
C7—C1—C6—C5179.0 (2)C8—C9—C10—C11179.78 (19)
C2—C1—C7—N1177.71 (19)C12—C9—C10—N2178.7 (2)
C6—C1—C7—N12.5 (3)C12—C9—C10—C111.9 (3)
Symmetry codes: (i) x1, y, z1; (ii) x, y, z; (iii) x1, y, z; (iv) x+1, y, z; (v) x+2, y, z+1; (vi) x2, y, z1; (vii) x+1, y, z+1.
Hydrogen-bond geometry (Å, º) top
Cg1 is the centroid of the O1/N2/C10/C9/C8 ring.
D—H···AD—HH···AD···AD—H···A
C7—H7···O10.932.342.704 (3)103
C11—H11C···Cg1iv0.962.913.644 (2)134
Symmetry code: (iv) x+1, y, z.

Experimental details

Crystal data
Chemical formulaC12H11ClN2O
Mr234.68
Crystal system, space groupMonoclinic, P21/n
Temperature (K)296
a, b, c (Å)5.0877 (2), 24.5197 (9), 9.4673 (4)
β (°) 94.871 (2)
V3)1176.77 (8)
Z4
Radiation typeMo Kα
µ (mm1)0.30
Crystal size (mm)0.30 × 0.16 × 0.14
Data collection
DiffractometerBruker KAPPA APEXII CCD
Absorption correctionMulti-scan
(SADABS; Bruker, 2005)
Tmin, Tmax0.868, 0.965
No. of measured, independent and
observed [I > 2σ(I)] reflections
9016, 2112, 1539
Rint0.030
(sin θ/λ)max1)0.600
Refinement
R[F2 > 2σ(F2)], wR(F2), S 0.044, 0.120, 1.07
No. of reflections2112
No. of parameters147
H-atom treatmentH-atom parameters constrained
Δρmax, Δρmin (e Å3)0.15, 0.14

Computer programs: APEX2 (Bruker, 2009), SAINT (Bruker, 2009), SHELXS97 (Sheldrick, 2008), SHELXL97 (Sheldrick, 2008), ORTEP-3 for Windows (Farrugia, 1997) and PLATON (Spek, 2009), WinGX (Farrugia, 1999) and PLATON (Spek, 2009).

Hydrogen-bond geometry (Å, º) top
Cg1 is the centroid of the O1/N2/C10/C9/C8 ring.
D—H···AD—HH···AD···AD—H···A
C7—H7···O10.932.342.704 (3)103
C11—H11C···Cg1i0.962.913.644 (2)134
Symmetry code: (i) x+1, y, z.
 

Acknowledgements

The authors would like to thank the Chemistry Department, King Abdul Aziz University, Jeddah, Saudi Arabia for providing research facilities.

References

First citationAsiri, A. M., Khan, S. A. & Tahir, M. N. (2010a). Acta Cryst. E66, o2077.  Web of Science CSD CrossRef IUCr Journals Google Scholar
First citationAsiri, A. M., Khan, S. A., Tan, K. W. & Ng, S. W. (2010b). Acta Cryst. E66, o1783.  Web of Science CSD CrossRef IUCr Journals Google Scholar
First citationBernstein, J., Davis, R. E., Shimoni, L. & Chang, N.-L. (1995). Angew. Chem. Int. Ed. Engl. 34, 1555–1573.  CrossRef CAS Web of Science Google Scholar
First citationBruker (2005). SADABS. Bruker AXS Inc., Madison, Wisconsin, USA.  Google Scholar
First citationBruker (2009). APEX2 and SAINT. Bruker AXS Inc., Madison, Wisconsin, USA.  Google Scholar
First citationFarrugia, L. J. (1997). J. Appl. Cryst. 30, 565.  CrossRef IUCr Journals Google Scholar
First citationFarrugia, L. J. (1999). J. Appl. Cryst. 32, 837–838.  CrossRef CAS IUCr Journals Google Scholar
First citationFun, H.-K., Hemamalini, M., Asiri, A. M. & Khan, S. A. (2010a). Acta Cryst. E66, o1037–o1038.  Web of Science CSD CrossRef IUCr Journals Google Scholar
First citationFun, H.-K., Hemamalini, M., Asiri, A. M., Khan, S. A. & Khan, K. A. (2010b). Acta Cryst. E66, o773–o774.  Web of Science CrossRef IUCr Journals Google Scholar
First citationShad, H. A., Chohan, Z. H., Tahir, M. N. & Khan, I. U. (2008). Acta Cryst. E64, o635.  Web of Science CSD CrossRef IUCr Journals 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 citationTahir, M. N., Chohan, Z. H., Shad, H. A. & Khan, I. U. (2008). Acta Cryst. E64, o720.  Web of Science CSD CrossRef IUCr Journals Google Scholar

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