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

Journal logoCRYSTALLOGRAPHIC
COMMUNICATIONS
ISSN: 2056-9890

2-Hy­dr­oxy-5-nitro-N-phenyl­benzamide

aDepartment of Chemistry, University of Sargodha, Sargodha, Pakistan, and bDepartment of Physics, University of Sargodha, Sargodha, Pakistan
*Correspondence e-mail: dmntahir_uos@yahoo.com

(Received 22 June 2010; accepted 23 June 2010; online 26 June 2010)

The mol­ecule of the title compound, C13H10N2O4, is almost planar with a dihedral angle between the benzene rings of 1.99 (13)°. The nitro group and its parent benzene ring are oriented at a dihedral angle of 7.6 (3)°. Intra­molecular C—H⋯O and N—H⋯O hydrogen bonds form two planar S(6) motifs. Inter­molecular O—H⋯O=C hydrogen bonds join mol­ecules into chains extending along the c axis.

Related literature

For similar structures, see: Raza et al. (2009a[Raza, A. R., Danish, M., Tahir, M. N., Nisar, B. & Park, G. (2009a). Acta Cryst. E65, o1042.],b[Raza, A. R., Tahir, M. N., Nisar, B., Danish, M. & Iqbal, M. S. (2009b). Acta Cryst. E65, o3260.]). For graph-set notation of hydrogen-bond motifs, 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
  • C13H10N2O4

  • Mr = 258.23

  • Monoclinic, P c

  • a = 9.9012 (2) Å

  • b = 4.7821 (1) Å

  • c = 12.3369 (4) Å

  • β = 97.919 (1)°

  • V = 578.56 (3) Å3

  • Z = 2

  • Mo Kα radiation

  • μ = 0.11 mm−1

  • T = 296 K

  • 0.34 × 0.12 × 0.10 mm

Data collection
  • Bruker Kappa APEXII CCD diffractometer

  • Absorption correction: multi-scan (SADABS; Bruker, 2009[Bruker (2009). APEX2, SAINT and SADABS. Bruker AXS Inc. Madison, Wisconsin, USA.]) Tmin = 0.979, Tmax = 0.988

  • 4381 measured reflections

  • 1042 independent reflections

  • 966 reflections with I > 2σ(I)

  • Rint = 0.022

Refinement
  • R[F2 > 2σ(F2)] = 0.029

  • wR(F2) = 0.071

  • S = 1.06

  • 1042 reflections

  • 173 parameters

  • 2 restraints

  • H-atom parameters constrained

  • Δρmax = 0.13 e Å−3

  • Δρmin = −0.13 e Å−3

Table 1
Hydrogen-bond geometry (Å, °)

D—H⋯A D—H H⋯A DA D—H⋯A
O1—H1⋯O4i 0.82 1.79 2.609 (2) 176
N2—H2A⋯O1 0.86 1.95 2.675 (2) 141
C2—H2⋯O4i 0.93 2.54 3.212 (3) 130
C9—H9⋯O4 0.93 2.26 2.853 (3) 121
C11—H11⋯O2ii 0.93 2.59 3.335 (4) 137
Symmetry codes: (i) [x, -y+2, z-{\script{1\over 2}}]; (ii) x-1, y-2, z.

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: 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 (I), (Fig. 1) has been synthesized as a precursor for benzoxazepines.

Previously, we have reported the crystal structures of N-phenyl-2-hydroxy-3-nitrobenzamide (Raza et al., 2009a). The title compound differs from it due to the attachement of nitro group at position-5 instead of position-3. We, also have reported the crystal structure of 2-hydroxy-5-nitrobenzamide (Raza et al., 2009b) which is related to (I).

In (I), the phenyl rings, A (C1–C6) of 2-hydroxy-5-nitrobenzamide and B (C8–C13) attached with 2-hydroxy-5-nitrobenzamide are planar with r. m. s. deviation of 0.0027 Å and 0.0031 Å, respectively. The O-atom of hydroxy group is at a distance of 0.014 (3) Å from the mean square plane of parent ring A. Nitro group C (O2/N1/O3) is of course planar. The dihedral angle between A/B, A/C and B/C is 1.99 (13)°, 7.63 (33)° and 6.20 (34)°, respectively. There exist a weak intramolecular H-bonding of C—H···O type forming an S(5) and a S(6) ring motif (Bernstein et al., 1995), whereas H-bonding of N—H···O type complete an S(6) ring motif. The intermolecular H-bonding of C—H···O and O—H···O types complete R21(6) ring motif (Table 1, Fig. 2). The molecules are essentially stabilized in the form of one dimensional chains extending along the c-axis. However, weak interactions of C—H···O type form 2-dimensional polymeric sheets (Fig. 2).

Related literature top

For similar structures, see: Raza et al. (2009a,b). For graph-set notation of hydrogen-bond motifs, see: Bernstein et al. (1995).

Experimental top

A solution of N-pheny-2-hydroxybenzamide (5.3 g, 0.025 mol) in ethyl acetate (EtOAc) (25 mL) was added dropwise to a nitrating mixture of HNO3 (2.25 mL, 3.15 g , 0.05 mol) and H2SO4 (1.33 mL, 2.45 g, 0.025 mol) with constant stirring while the temperature was kept below 278 K. The reaction mixture was refluxed for 5 h, cooled to room temperature, neutralized with aqueous NaHCO3 (10%) and extracted with EtOAc (3 × 25 mL). The organic extract was combined, dried over anhydrous Na2SO4, filtered and concentrated under reduced pressure to afford reddish brown solid. The column chromatographic purification with 0, 2.5, and 5 % EtOAc in n-hexane (0.5 L each) over a silica gel packed column (25.5 cm) afforded the title compound I in 5th-34th fraction of 50 mL each upon leaving at room temperature.

Refinement top

In the absence of significant anomalous scattering effects, all Friedal pairs were merged. All H atoms were found in difference Fourier maps however for the refinement they were positioned geometrically with O–H = 0.82, N–H= 0.86 and C–H = 0.93 Å and refined as riding with Uiso(H) = 1.2Ueq(C, N) and Uiso(H) = 1.5Ueq(O).

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 by small circles of arbitrary radii.
[Figure 2] Fig. 2. The partial packing (PLATON; Spek, 2009) which shows that molecules form polymeric chains extending along the c-axis. Hydrogen bonds are shown by dashed lines.
2-Hydroxy-5-nitro-N-phenylbenzamide top
Crystal data top
C13H10N2O4F(000) = 268
Mr = 258.23Dx = 1.482 Mg m3
Monoclinic, PcMo Kα radiation, λ = 0.71073 Å
Hall symbol: P -2ycCell parameters from 931 reflections
a = 9.9012 (2) Åθ = 2.8–26.0°
b = 4.7821 (1) ŵ = 0.11 mm1
c = 12.3369 (4) ÅT = 296 K
β = 97.919 (1)°Needle, colorless
V = 578.56 (3) Å30.34 × 0.12 × 0.10 mm
Z = 2
Data collection top
Bruker Kappa APEXII CCD
diffractometer
1042 independent reflections
Radiation source: fine-focus sealed tube966 reflections with I > 2σ(I)
Graphite monochromatorRint = 0.022
Detector resolution: 8.20 pixels mm-1θmax = 25.3°, θmin = 3.7°
ω scansh = 1111
Absorption correction: multi-scan
(SADABS; Bruker, 2009)
k = 55
Tmin = 0.979, Tmax = 0.988l = 1414
4381 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)] = 0.029Hydrogen site location: inferred from neighbouring sites
wR(F2) = 0.071H-atom parameters constrained
S = 1.06 w = 1/[σ2(Fo2) + (0.0447P)2 + 0.0284P]
where P = (Fo2 + 2Fc2)/3
1042 reflections(Δ/σ)max < 0.001
173 parametersΔρmax = 0.13 e Å3
2 restraintsΔρmin = 0.13 e Å3
Crystal data top
C13H10N2O4V = 578.56 (3) Å3
Mr = 258.23Z = 2
Monoclinic, PcMo Kα radiation
a = 9.9012 (2) ŵ = 0.11 mm1
b = 4.7821 (1) ÅT = 296 K
c = 12.3369 (4) Å0.34 × 0.12 × 0.10 mm
β = 97.919 (1)°
Data collection top
Bruker Kappa APEXII CCD
diffractometer
1042 independent reflections
Absorption correction: multi-scan
(SADABS; Bruker, 2009)
966 reflections with I > 2σ(I)
Tmin = 0.979, Tmax = 0.988Rint = 0.022
4381 measured reflections
Refinement top
R[F2 > 2σ(F2)] = 0.0292 restraints
wR(F2) = 0.071H-atom parameters constrained
S = 1.06Δρmax = 0.13 e Å3
1042 reflectionsΔρmin = 0.13 e Å3
173 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 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 > 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
O10.87642 (17)0.9971 (4)0.04316 (13)0.0503 (6)
O21.3304 (2)1.6021 (5)0.27212 (18)0.0782 (8)
O31.2680 (2)1.2889 (5)0.38093 (16)0.0688 (8)
O40.88497 (17)0.7133 (3)0.27868 (13)0.0484 (5)
N11.25998 (19)1.4015 (5)0.29149 (17)0.0502 (7)
N20.78477 (17)0.6615 (4)0.10417 (14)0.0398 (6)
C10.9697 (2)1.0963 (5)0.03785 (17)0.0374 (7)
C21.0633 (2)1.2998 (5)0.01674 (19)0.0452 (8)
C31.1591 (2)1.4007 (5)0.09772 (19)0.0440 (8)
C41.1606 (2)1.2957 (5)0.20283 (19)0.0395 (7)
C51.0696 (2)1.0964 (5)0.22608 (17)0.0382 (7)
C60.9712 (2)0.9923 (4)0.14475 (17)0.0353 (7)
C70.8756 (2)0.7790 (4)0.18042 (17)0.0356 (6)
C80.6844 (2)0.4564 (4)0.11679 (19)0.0378 (7)
C90.6723 (3)0.3201 (5)0.2141 (2)0.0467 (8)
C100.5716 (3)0.1191 (5)0.2159 (2)0.0562 (9)
C110.4843 (3)0.0530 (5)0.1231 (3)0.0565 (9)
C120.4959 (2)0.1904 (5)0.0268 (2)0.0563 (9)
C130.5957 (3)0.3893 (5)0.0230 (2)0.0494 (8)
H10.882281.083140.099820.0754*
H21.060611.368560.054040.0542*
H2A0.787310.717550.038240.0477*
H31.221491.535930.082840.0528*
H51.073511.029730.297270.0459*
H90.730900.363010.277440.0561*
H100.563220.027350.281110.0674*
H110.417780.083470.125370.0677*
H120.435980.148770.035970.0675*
H130.603790.479160.042610.0592*
Atomic displacement parameters (Å2) top
U11U22U33U12U13U23
O10.0561 (9)0.0674 (11)0.0251 (9)0.0152 (8)0.0027 (7)0.0045 (8)
O20.0822 (13)0.0874 (15)0.0612 (13)0.0397 (13)0.0041 (10)0.0068 (11)
O30.0754 (13)0.0863 (14)0.0391 (12)0.0147 (11)0.0117 (9)0.0010 (10)
O40.0645 (10)0.0525 (9)0.0267 (9)0.0075 (8)0.0014 (7)0.0006 (7)
N10.0480 (11)0.0581 (13)0.0424 (13)0.0011 (10)0.0009 (9)0.0086 (10)
N20.0470 (11)0.0462 (11)0.0258 (10)0.0058 (8)0.0041 (8)0.0007 (8)
C10.0381 (11)0.0458 (12)0.0275 (12)0.0011 (10)0.0016 (8)0.0024 (9)
C20.0503 (14)0.0554 (14)0.0301 (13)0.0010 (11)0.0060 (10)0.0036 (10)
C30.0416 (12)0.0488 (14)0.0419 (14)0.0062 (10)0.0067 (10)0.0030 (11)
C40.0372 (11)0.0447 (12)0.0356 (13)0.0026 (10)0.0014 (9)0.0067 (10)
C50.0429 (12)0.0432 (12)0.0279 (12)0.0038 (10)0.0026 (9)0.0006 (9)
C60.0386 (11)0.0378 (12)0.0288 (12)0.0050 (9)0.0026 (8)0.0015 (8)
C70.0427 (11)0.0380 (11)0.0258 (11)0.0029 (10)0.0032 (8)0.0015 (9)
C80.0392 (11)0.0380 (12)0.0364 (12)0.0033 (9)0.0063 (9)0.0007 (9)
C90.0515 (13)0.0488 (14)0.0396 (14)0.0017 (11)0.0056 (10)0.0038 (11)
C100.0593 (15)0.0536 (15)0.0581 (18)0.0024 (12)0.0169 (13)0.0125 (12)
C110.0476 (13)0.0478 (14)0.075 (2)0.0085 (11)0.0117 (13)0.0008 (13)
C120.0479 (14)0.0542 (15)0.0637 (18)0.0065 (12)0.0030 (12)0.0065 (13)
C130.0534 (14)0.0517 (15)0.0412 (14)0.0063 (12)0.0002 (11)0.0012 (11)
Geometric parameters (Å, º) top
O1—C11.350 (3)C6—C71.498 (3)
O2—N11.229 (3)C8—C131.390 (3)
O3—N11.221 (3)C8—C91.386 (3)
O4—C71.243 (3)C9—C101.387 (4)
O1—H10.8200C10—C111.373 (4)
N1—C41.457 (3)C11—C121.376 (4)
N2—C81.420 (3)C12—C131.377 (3)
N2—C71.333 (3)C2—H20.9300
N2—H2A0.8600C3—H30.9300
C1—C61.408 (3)C5—H50.9300
C1—C21.393 (3)C9—H90.9300
C2—C31.367 (3)C10—H100.9300
C3—C41.389 (3)C11—H110.9300
C4—C51.369 (3)C12—H120.9300
C5—C61.391 (3)C13—H130.9300
O1···N22.675 (2)C8···C11viii3.480 (3)
O1···O4i2.609 (2)C8···C6vii3.583 (3)
O2···C11ii3.335 (4)C8···C1vii3.557 (3)
O3···C3iii3.364 (3)C9···C7vii3.339 (3)
O4···C2iv3.212 (3)C9···O42.853 (3)
O4···C92.853 (3)C9···C6vii3.556 (3)
O4···O1iv2.609 (2)C10···C7vii3.501 (3)
O4···C1iv3.319 (3)C11···C8vii3.480 (3)
O1···H2A1.9500C11···C3xi3.599 (4)
O2···H32.4500C11···O2xii3.335 (4)
O2···H12v2.7300C1···H2A2.5600
O2···H11ii2.5900C7···H92.8100
O3···H52.4000C7···H1iv2.7800
O3···H12vi2.7800H1···H22.2400
O3···H2iii2.8300H1···O4i1.7900
O3···H3iii2.7300H1···C7i2.7800
O4···H52.3900H1···H5i2.4800
O4···H92.2600H2···H12.2400
O4···H1iv1.7900H2···O3x2.8300
O4···H2iv2.5400H2···O4i2.5400
N2···O12.675 (2)H2A···O11.9500
N2···C1vii3.426 (3)H2A···C12.5600
C1···N2viii3.426 (3)H2A···H132.2600
C1···C8viii3.557 (3)H3···O22.4500
C1···O4i3.319 (3)H3···O3x2.7300
C2···O4i3.212 (3)H5···O32.4000
C3···C6viii3.478 (3)H5···O42.3900
C3···C11ix3.599 (4)H5···H1iv2.4800
C3···O3x3.364 (3)H9···O42.2600
C6···C8viii3.583 (3)H9···C72.8100
C6···C3vii3.478 (3)H11···O2xii2.5900
C6···C9viii3.556 (3)H12···O2xiii2.7300
C7···C10viii3.501 (3)H12···O3xiv2.7800
C7···C9viii3.339 (3)H13···H2A2.2600
C1—O1—H1109.00N2—C8—C13116.1 (2)
O2—N1—O3123.5 (2)C9—C8—C13119.5 (2)
O2—N1—C4117.9 (2)C8—C9—C10119.2 (2)
O3—N1—C4118.6 (2)C9—C10—C11121.2 (2)
C7—N2—C8128.92 (18)C10—C11—C12119.5 (2)
C8—N2—H2A116.00C11—C12—C13120.3 (2)
C7—N2—H2A116.00C8—C13—C12120.3 (2)
O1—C1—C2120.8 (2)C1—C2—H2119.00
O1—C1—C6119.16 (19)C3—C2—H2119.00
C2—C1—C6120.04 (19)C2—C3—H3121.00
C1—C2—C3121.5 (2)C4—C3—H3121.00
C2—C3—C4118.2 (2)C4—C5—H5120.00
N1—C4—C3119.6 (2)C6—C5—H5119.00
N1—C4—C5118.7 (2)C8—C9—H9120.00
C3—C4—C5121.7 (2)C10—C9—H9120.00
C4—C5—C6120.9 (2)C9—C10—H10119.00
C5—C6—C7116.10 (18)C11—C10—H10119.00
C1—C6—C7126.17 (19)C10—C11—H11120.00
C1—C6—C5117.73 (19)C12—C11—H11120.00
O4—C7—N2122.28 (19)C11—C12—H12120.00
O4—C7—C6119.55 (18)C13—C12—H12120.00
N2—C7—C6118.16 (18)C8—C13—H13120.00
N2—C8—C9124.4 (2)C12—C13—H13120.00
O3—N1—C4—C3173.4 (2)N1—C4—C5—C6178.9 (2)
O2—N1—C4—C5171.8 (2)C3—C4—C5—C60.4 (3)
O2—N1—C4—C37.4 (3)C4—C5—C6—C10.8 (3)
O3—N1—C4—C57.4 (3)C4—C5—C6—C7178.9 (2)
C8—N2—C7—C6179.93 (17)C1—C6—C7—N24.2 (3)
C7—N2—C8—C96.5 (3)C5—C6—C7—O42.4 (3)
C8—N2—C7—O41.4 (3)C5—C6—C7—N2176.16 (19)
C7—N2—C8—C13174.8 (2)C1—C6—C7—O4177.2 (2)
C6—C1—C2—C30.8 (3)N2—C8—C9—C10178.7 (2)
O1—C1—C6—C5179.3 (2)C13—C8—C9—C100.0 (4)
O1—C1—C2—C3179.5 (2)N2—C8—C13—C12179.3 (2)
C2—C1—C6—C51.0 (3)C9—C8—C13—C120.5 (4)
C2—C1—C6—C7178.6 (2)C8—C9—C10—C110.1 (4)
O1—C1—C6—C71.2 (3)C9—C10—C11—C120.7 (4)
C1—C2—C3—C40.3 (3)C10—C11—C12—C131.1 (4)
C2—C3—C4—C50.1 (3)C11—C12—C13—C81.0 (4)
C2—C3—C4—N1179.1 (2)
Symmetry codes: (i) x, y+2, z1/2; (ii) x+1, y+2, z; (iii) x, y+3, z+1/2; (iv) x, y+2, z+1/2; (v) x+1, y+2, z+1/2; (vi) x+1, y+1, z+1/2; (vii) x, y1, z; (viii) x, y+1, z; (ix) x+1, y+1, z; (x) x, y+3, z1/2; (xi) x1, y1, z; (xii) x1, y2, z; (xiii) x1, y+2, z1/2; (xiv) x1, y+1, z1/2.
Hydrogen-bond geometry (Å, º) top
D—H···AD—HH···AD···AD—H···A
O1—H1···O4i0.821.792.609 (2)176
N2—H2A···O10.861.952.675 (2)141
C2—H2···O4i0.932.543.212 (3)130
C5—H5···O40.932.392.729 (3)101
C9—H9···O40.932.262.853 (3)121
C11—H11···O2xii0.932.593.335 (4)137
Symmetry codes: (i) x, y+2, z1/2; (xii) x1, y2, z.

Experimental details

Crystal data
Chemical formulaC13H10N2O4
Mr258.23
Crystal system, space groupMonoclinic, Pc
Temperature (K)296
a, b, c (Å)9.9012 (2), 4.7821 (1), 12.3369 (4)
β (°) 97.919 (1)
V3)578.56 (3)
Z2
Radiation typeMo Kα
µ (mm1)0.11
Crystal size (mm)0.34 × 0.12 × 0.10
Data collection
DiffractometerBruker Kappa APEXII CCD
diffractometer
Absorption correctionMulti-scan
(SADABS; Bruker, 2009)
Tmin, Tmax0.979, 0.988
No. of measured, independent and
observed [I > 2σ(I)] reflections
4381, 1042, 966
Rint0.022
(sin θ/λ)max1)0.600
Refinement
R[F2 > 2σ(F2)], wR(F2), S 0.029, 0.071, 1.06
No. of reflections1042
No. of parameters173
No. of restraints2
H-atom treatmentH-atom parameters constrained
Δρmax, Δρmin (e Å3)0.13, 0.13

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
D—H···AD—HH···AD···AD—H···A
O1—H1···O4i0.821.792.609 (2)176
N2—H2A···O10.861.952.675 (2)141
C2—H2···O4i0.932.543.212 (3)130
C5—H5···O40.932.392.729 (3)101
C9—H9···O40.932.262.853 (3)121
C11—H11···O2ii0.932.593.335 (4)137
Symmetry codes: (i) x, y+2, z1/2; (ii) x1, y2, z.
 

Acknowledgements

The authors acknowledge the provision of funds for the purchase of diffractometer and encouragement by Dr Muhammad Akram Chaudhary, Vice Chancellor, University of Sargodha, Pakistan. ARR also acknowledges the Higher Education Commission, Government of Pakistan, for generous support of a research project (20-819).

References

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 (2009). APEX2, SAINT and SADABS. 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 citationRaza, A. R., Danish, M., Tahir, M. N., Nisar, B. & Park, G. (2009a). Acta Cryst. E65, o1042.  Web of Science CSD CrossRef IUCr Journals Google Scholar
First citationRaza, A. R., Tahir, M. N., Nisar, B., Danish, M. & Iqbal, M. S. (2009b). Acta Cryst. E65, o3260.  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

This is an open-access article distributed under the terms of the Creative Commons Attribution (CC-BY) Licence, which permits unrestricted use, distribution, and reproduction in any medium, provided the original authors and source are cited.

Journal logoCRYSTALLOGRAPHIC
COMMUNICATIONS
ISSN: 2056-9890
Follow Acta Cryst. E
Sign up for e-alerts
Follow Acta Cryst. on Twitter
Follow us on facebook
Sign up for RSS feeds