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

Journal logoCRYSTALLOGRAPHIC
COMMUNICATIONS
ISSN: 2056-9890

Ethyl 2-(3,5-di­nitro­benzamido)­benzoate

aDepartment of Chemistry, Research Complex, Allama Iqbal Open Unicversity, Islamabad 44000, Pakistan, bNational Engineering & Scientific Commission, PO Box 2801, Islamabad, Pakistan, and cDepartment of Chemistry, The University of Hong Kong, Pokfulam Road, Pokfulam, Hong Kong SAR, People's Republic of China
*Correspondence e-mail: Sohail262001@yahoo.com

(Received 28 November 2011; accepted 9 December 2011; online 14 December 2011)

The title mol­ecule, C16H13N3O7, is slightly twisted, with the dihedral angle between the two benzene ring planes being 17.4 (1)°. An intra­molecular N—H⋯O hydrogen bond is observed. In the crystal, weak C—H⋯O hydrogen bonds link the mol­ecules into chains along the b axis.

Related literature

For background to the biological activity of N-substituted benzamides and their use in synthesis, see: Saeed et al. (2011a[Saeed, S., Jasinski, J. P. & Butcher, R. J. (2011a). Acta Cryst. E67, o279.],b[Saeed, S., Rashid, N., Ng, S. W. & Tiekink, E. R. T. (2011b). Acta Cryst. E67, o1194.]). For the structures of related chloro­phenyl­benzamides, see: Gowda et al. (2007a[Gowda, B. T., Sowmya, B. P., Kožíšek, J., Tokarčík, M. & Fuess, H. (2007a). Acta Cryst. E63, o2906.],b[Gowda, B. T., Sowmya, B. P., Tokarčík, M., Kožíšek, J. & Fuess, H. (2007b). Acta Cryst. E63, o3326.],c[Gowda, B. T., Sowmya, B. P., Tokarčík, M., Kožíšek, J. & Fuess, H. (2007c). Acta Cryst. E63, o3365.]). For hydrogen-bond motifs, see: Bernstein et al. (1995[Bernstein, J., Davis, R. E., Shimoni, L. & Chang, N.-L. (1995). Angew. Chem. Int. Ed. 341, 555-1573.]). For 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 ortho-hydrogen steric hindrance, see: Karle & Brockway (1944[Karle, I. L. & Brockway, L. O. (1944). J. Am. Chem. Soc. 66, 1974-1979.]).

[Scheme 1]

Experimental

Crystal data
  • C16H13N3O7

  • Mr = 359.29

  • Monoclinic, P 21 /c

  • a = 12.4662 (4) Å

  • b = 17.7213 (5) Å

  • c = 7.4352 (2) Å

  • β = 96.658 (2)°

  • V = 1631.49 (8) Å3

  • Z = 4

  • Mo Kα radiation

  • μ = 0.12 mm−1

  • T = 296 K

  • 0.52 × 0.30 × 0.26 mm

Data collection
  • Bruker APEXII CCD diffractometer

  • Absorption correction: multi-scan (SADABS; Sheldrick, 2004[Sheldrick, G. M. (2004). SADABS. University of Göttingen, Germany.]) Tmin = 0.942, Tmax = 0.970

  • 16092 measured reflections

  • 2808 independent reflections

  • 1961 reflections with I > 2σ(I)

  • Rint = 0.040

Refinement
  • R[F2 > 2σ(F2)] = 0.049

  • wR(F2) = 0.174

  • S = 1.11

  • 2808 reflections

  • 237 parameters

  • H-atom parameters constrained

  • Δρmax = 0.18 e Å−3

  • Δρmin = −0.22 e Å−3

Table 1
Hydrogen-bond geometry (Å, °)

D—H⋯A D—H H⋯A DA D—H⋯A
N1—H1⋯O2 0.86 1.92 2.641 (3) 140
C16—H16A⋯O3i 0.96 2.55 3.402 (4) 148
Symmetry code: (i) [-x+1, y+{\script{1\over 2}}, -z+{\script{3\over 2}}].

Data collection: APEX2 (Bruker, 2007[Bruker (2007). APEX2 and SAINT, Bruker AXS Inc., Madison, Wisconsin, USA.]); cell refinement: SAINT (Bruker, 2007[Bruker (2007). 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: Mercury (Macrae et al., 2008[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.]); software used to prepare material for publication: SHELXL97.

Supporting information


Comment top

In spite of the fact that the molecule is an extensively conjugated aromatic system, the molecule is not co-planar. This may be due to the steric hindrance between the ortho-H ··· amide H-atoms. The twisting away from coplanarity may help to relief this steric hindrance and results in an H14···H1 distance of 2.016 Å. This is in analogy to Karle and Brockway's suggestion that the steric hindrance between the ortho hydrogen atoms in biphenyl may be the reason for the non-coplanarity of the structure (Karle and Brockway, 1944). The dihedral angle between the two phenyl ring planes is about 17.4 (1)°. Both nitro groups are slightly twisted, 4.9 (2)° and 4.0 (2)° respectively, from the phenyl ring plane, C9—C11.

There is an intra-molecular N1—H1···O2 interaction. A weak intermolecular C16—H16A···O3(1 - x,1/2 + y,3/2 - z) hydrogen bond may help to align the molecules to endless chains along the b-axis in the crystal lattice. In addition, the conjugated ring planes of the title molecules are stacked along the c-axis with perpendicular distance between ring planes being 3.38 (1) Å.

Related literature top

For background to the biological activity of N-substituted benzamides and their use in synthesis, see: Saeed et al. (2011a,b).For the structures of related chlorophenylbenzamides, see: Gowda et al. (2007a,b,c). For hydrogen-bond motifs, see: Bernstein et al. (1995). For bond-length data, see: Allen et al. (1987). For ortho-hydrogen steric hindrance, see: Karle & Brockway (1944).

Experimental top

To a 250 ml round flask fitted with a condenser ethyl ortho-amino benzoate (0.1 mol), dichloromethane (15 ml) and triethylamine (0.5 ml) was added under stirring. 3,5-dinitroenzoyl chloride (0.1 mol) was added gradually. The reaction mixture was stirred at room temperature for 1 h and then refluxed for 2 h. The product precipitated as a colourless powder, which was washed three times with water and dichloromethane. Recrystallization from ethyl acetate produced the crystals of the title compound.

Refinement top

The structure was solved by direct methods (SHELXS97, Sheldrick, 2008) and expanded using Fourier techniques. All non-H atoms were refined anisotropically.

All H atoms are observable from difference Fourier map but were refined riding at idealized geometrical positions with C—H = 0.93, 0.96 and 0.97Å for phenyl, methyl and methylene H-atoms and N—H = 0.86 Å and Uiso(H) = 1.2Ueq(C / N) and Uiso(H) = 1.5Ueq(C-methyl).

Computing details top

Data collection: APEX2 (Bruker, 2007); cell refinement: APEX2 (Bruker, 2007); data reduction: SAINT (Bruker, 2007); program(s) used to solve structure: SHELXS97 (Sheldrick, 2008); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008); molecular graphics: Mercury (Macrae et al., 2008); software used to prepare material for publication: SHELXL97 (Sheldrick, 2008).

Figures top
[Figure 1] Fig. 1. Molecular structure of the title compound with displacement ellipsoids at the 50% probability level.
[Figure 2] Fig. 2. The packing diagram of the compound projected along the c-axis.
Ethyl 2-(3,5-dinitrobenzamido)benzoate top
Crystal data top
C16H13N3O7F(000) = 744
Mr = 359.29Dx = 1.463 Mg m3
Monoclinic, P21/cMo Kα radiation, λ = 0.71073 Å
Hall symbol: -P 2ybcCell parameters from 16092 reflections
a = 12.4662 (4) Åθ = 2.8–25.0°
b = 17.7213 (5) ŵ = 0.12 mm1
c = 7.4352 (2) ÅT = 296 K
β = 96.658 (2)°Block, colourless
V = 1631.49 (8) Å30.52 × 0.30 × 0.26 mm
Z = 4
Data collection top
Bruker APEXII CCD
diffractometer
2808 independent reflections
Radiation source: fine-focus sealed tube1961 reflections with I > 2σ(I)
Graphite monochromatorRint = 0.040
ω and ϕ scanθmax = 25.0°, θmin = 2.8°
Absorption correction: multi-scan
(SADABS; Sheldrick, 2004)
h = 1414
Tmin = 0.942, Tmax = 0.970k = 2121
16092 measured reflectionsl = 88
Refinement top
Refinement on F2Secondary atom site location: difference Fourier map
Least-squares matrix: fullHydrogen site location: inferred from neighbouring sites
R[F2 > 2σ(F2)] = 0.049H-atom parameters constrained
wR(F2) = 0.174 w = 1/[σ2(Fo2) + (0.0679P)2 + 0.9448P]
where P = (Fo2 + 2Fc2)/3
S = 1.11(Δ/σ)max < 0.001
2808 reflectionsΔρmax = 0.18 e Å3
237 parametersΔρmin = 0.22 e Å3
0 restraintsExtinction correction: SHELXL97 (Sheldrick, 2008), Fc*=kFc[1+0.001xFc2λ3/sin(2θ)]-1/4
Primary atom site location: structure-invariant direct methodsExtinction coefficient: 0.013 (2)
Crystal data top
C16H13N3O7V = 1631.49 (8) Å3
Mr = 359.29Z = 4
Monoclinic, P21/cMo Kα radiation
a = 12.4662 (4) ŵ = 0.12 mm1
b = 17.7213 (5) ÅT = 296 K
c = 7.4352 (2) Å0.52 × 0.30 × 0.26 mm
β = 96.658 (2)°
Data collection top
Bruker APEXII CCD
diffractometer
2808 independent reflections
Absorption correction: multi-scan
(SADABS; Sheldrick, 2004)
1961 reflections with I > 2σ(I)
Tmin = 0.942, Tmax = 0.970Rint = 0.040
16092 measured reflections
Refinement top
R[F2 > 2σ(F2)] = 0.0490 restraints
wR(F2) = 0.174H-atom parameters constrained
S = 1.11Δρmax = 0.18 e Å3
2808 reflectionsΔρmin = 0.22 e Å3
237 parameters
Special details top

Geometry. All e.s.d.'s (except the e.s.d. in the dihedral angle between two l.s. planes) are estimated using the full covariance matrix. The cell e.s.d.'s are taken into account individually in the estimation of e.s.d.'s in distances, angles and torsion angles; correlations between e.s.d.'s in cell parameters are only used when they are defined by crystal symmetry. An approximate (isotropic) treatment of cell e.s.d.'s is used for estimating e.s.d.'s 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 > 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
O10.66429 (15)0.10807 (11)0.9056 (3)0.0724 (6)
O20.49758 (15)0.11624 (11)0.7638 (3)0.0678 (6)
O30.29471 (18)0.10623 (12)0.5275 (3)0.0855 (7)
O40.03437 (19)0.05325 (16)0.1499 (3)0.0870 (7)
O50.11189 (19)0.05489 (17)0.1563 (4)0.1005 (9)
O60.0466 (2)0.24889 (16)0.5560 (5)0.1221 (11)
O70.19530 (19)0.22737 (13)0.7234 (4)0.0908 (8)
N10.40070 (16)0.01091 (13)0.6539 (3)0.0560 (6)
H10.40200.03740.66540.067*
N20.0365 (2)0.01221 (19)0.2005 (3)0.0721 (7)
N30.1241 (2)0.20962 (15)0.6060 (4)0.0752 (7)
C10.5738 (2)0.07809 (15)0.8276 (3)0.0540 (6)
C20.57853 (19)0.00579 (14)0.8223 (3)0.0496 (6)
C30.6705 (2)0.04275 (16)0.9032 (4)0.0585 (7)
H30.72670.01470.96340.070*
C40.6794 (2)0.12038 (17)0.8952 (4)0.0691 (8)
H40.74080.14460.95020.083*
C50.5968 (3)0.16112 (17)0.8055 (5)0.0763 (9)
H50.60320.21330.79880.092*
C60.5043 (2)0.12685 (16)0.7246 (4)0.0676 (8)
H60.44910.15590.66480.081*
C70.4936 (2)0.04870 (15)0.7326 (3)0.0524 (6)
C80.3099 (2)0.03932 (16)0.5632 (4)0.0582 (7)
C90.22294 (19)0.01719 (15)0.5044 (3)0.0518 (6)
C100.1393 (2)0.00719 (16)0.3779 (3)0.0560 (7)
H100.14050.05550.32930.067*
C110.0544 (2)0.04096 (18)0.3248 (3)0.0588 (7)
C120.0482 (2)0.11277 (17)0.3938 (4)0.0627 (7)
H120.00950.14460.35680.075*
C130.1312 (2)0.13480 (15)0.5197 (4)0.0587 (7)
C140.2185 (2)0.08975 (15)0.5764 (4)0.0545 (6)
H140.27360.10730.66110.065*
C150.6721 (3)0.19029 (18)0.9047 (6)0.0866 (10)
H15A0.65050.20960.78380.104*
H15B0.62510.21190.98630.104*
C160.7843 (3)0.2102 (2)0.9632 (9)0.139 (2)
H16A0.79250.26400.95940.208*
H16B0.83020.18700.88410.208*
H16C0.80390.19261.08470.208*
Atomic displacement parameters (Å2) top
U11U22U33U12U13U23
O10.0586 (11)0.0578 (12)0.0953 (15)0.0026 (9)0.0149 (10)0.0026 (10)
O20.0540 (11)0.0594 (11)0.0863 (14)0.0043 (9)0.0075 (10)0.0016 (10)
O30.0770 (14)0.0613 (13)0.1109 (18)0.0009 (11)0.0198 (13)0.0172 (12)
O40.0805 (15)0.1026 (19)0.0738 (15)0.0281 (14)0.0077 (11)0.0029 (13)
O50.0623 (14)0.135 (2)0.0963 (18)0.0002 (14)0.0259 (13)0.0126 (16)
O60.0978 (19)0.101 (2)0.158 (3)0.0457 (16)0.0271 (18)0.0201 (18)
O70.0794 (15)0.0655 (14)0.122 (2)0.0015 (11)0.0130 (14)0.0100 (13)
N10.0480 (12)0.0551 (12)0.0622 (14)0.0009 (9)0.0043 (10)0.0008 (10)
N20.0546 (15)0.105 (2)0.0549 (14)0.0166 (15)0.0023 (11)0.0122 (14)
N30.0634 (15)0.0656 (15)0.093 (2)0.0088 (13)0.0045 (14)0.0049 (14)
C10.0465 (14)0.0586 (15)0.0560 (15)0.0011 (12)0.0016 (11)0.0001 (12)
C20.0458 (13)0.0576 (15)0.0452 (13)0.0029 (11)0.0045 (10)0.0006 (11)
C30.0506 (15)0.0693 (17)0.0544 (15)0.0061 (12)0.0004 (11)0.0038 (12)
C40.0638 (17)0.0657 (18)0.0753 (19)0.0196 (14)0.0021 (15)0.0069 (15)
C50.077 (2)0.0551 (17)0.094 (2)0.0141 (15)0.0024 (17)0.0024 (16)
C60.0644 (17)0.0556 (16)0.080 (2)0.0028 (13)0.0027 (14)0.0031 (14)
C70.0497 (14)0.0573 (15)0.0500 (14)0.0061 (11)0.0052 (11)0.0035 (11)
C80.0514 (15)0.0647 (17)0.0573 (15)0.0025 (12)0.0015 (12)0.0026 (13)
C90.0438 (13)0.0612 (16)0.0501 (14)0.0029 (11)0.0038 (11)0.0037 (12)
C100.0486 (14)0.0701 (17)0.0488 (14)0.0094 (12)0.0034 (11)0.0023 (12)
C110.0437 (14)0.085 (2)0.0463 (14)0.0120 (13)0.0009 (11)0.0105 (13)
C120.0464 (14)0.0742 (19)0.0664 (17)0.0013 (13)0.0016 (12)0.0177 (15)
C130.0488 (14)0.0588 (16)0.0682 (17)0.0017 (12)0.0053 (12)0.0104 (13)
C140.0458 (13)0.0598 (15)0.0565 (15)0.0060 (11)0.0001 (11)0.0051 (12)
C150.075 (2)0.0586 (18)0.121 (3)0.0012 (16)0.011 (2)0.0072 (18)
C160.086 (3)0.075 (3)0.243 (6)0.011 (2)0.036 (3)0.007 (3)
Geometric parameters (Å, º) top
O1—C11.319 (3)C5—C61.378 (4)
O1—C151.460 (4)C5—H50.9300
O2—C11.217 (3)C6—C71.393 (4)
O3—C81.225 (3)C6—H60.9300
O4—N21.221 (4)C8—C91.503 (4)
O5—N21.221 (4)C9—C101.390 (4)
O6—N31.214 (3)C9—C141.396 (4)
O7—N31.212 (3)C10—C111.381 (4)
N1—C81.346 (3)C10—H100.9300
N1—C71.405 (3)C11—C121.378 (4)
N1—H10.8600C12—C131.370 (4)
N2—C111.468 (3)C12—H120.9300
N3—C131.480 (4)C13—C141.376 (4)
C1—C21.488 (4)C14—H140.9300
C2—C31.395 (3)C15—C161.458 (5)
C2—C71.407 (4)C15—H15A0.9700
C3—C41.382 (4)C15—H15B0.9700
C3—H30.9300C16—H16A0.9600
C4—C51.366 (4)C16—H16B0.9600
C4—H40.9300C16—H16C0.9600
C1—O1—C15117.0 (2)O3—C8—C9119.6 (2)
C8—N1—C7129.4 (2)N1—C8—C9115.6 (2)
C8—N1—H1115.3C10—C9—C14119.1 (2)
C7—N1—H1115.3C10—C9—C8116.7 (2)
O5—N2—O4123.3 (3)C14—C9—C8124.1 (2)
O5—N2—C11117.9 (3)C11—C10—C9119.4 (3)
O4—N2—C11118.7 (3)C11—C10—H10120.3
O7—N3—O6124.2 (3)C9—C10—H10120.3
O7—N3—C13118.0 (2)C12—C11—C10122.6 (2)
O6—N3—C13117.8 (3)C12—C11—N2118.8 (3)
O2—C1—O1122.5 (2)C10—C11—N2118.4 (3)
O2—C1—C2125.2 (2)C13—C12—C11116.6 (3)
O1—C1—C2112.3 (2)C13—C12—H12121.7
C3—C2—C7119.1 (2)C11—C12—H12121.7
C3—C2—C1119.4 (2)C12—C13—C14123.5 (3)
C7—C2—C1121.5 (2)C12—C13—N3118.2 (2)
C4—C3—C2121.0 (3)C14—C13—N3118.2 (2)
C4—C3—H3119.5C13—C14—C9118.8 (2)
C2—C3—H3119.5C13—C14—H14120.6
C5—C4—C3119.2 (3)C9—C14—H14120.6
C5—C4—H4120.4C16—C15—O1107.6 (3)
C3—C4—H4120.4C16—C15—H15A110.2
C4—C5—C6121.7 (3)O1—C15—H15A110.2
C4—C5—H5119.2C16—C15—H15B110.2
C6—C5—H5119.2O1—C15—H15B110.2
C5—C6—C7119.9 (3)H15A—C15—H15B108.5
C5—C6—H6120.0C15—C16—H16A109.5
C7—C6—H6120.0C15—C16—H16B109.5
C6—C7—C2119.1 (2)H16A—C16—H16B109.5
C6—C7—N1122.3 (2)C15—C16—H16C109.5
C2—C7—N1118.6 (2)H16A—C16—H16C109.5
O3—C8—N1124.8 (3)H16B—C16—H16C109.5
Hydrogen-bond geometry (Å, º) top
D—H···AD—HH···AD···AD—H···A
N1—H1···O20.861.922.641 (3)140
C16—H16A···O3i0.962.553.402 (4)148
Symmetry code: (i) x+1, y+1/2, z+3/2.

Experimental details

Crystal data
Chemical formulaC16H13N3O7
Mr359.29
Crystal system, space groupMonoclinic, P21/c
Temperature (K)296
a, b, c (Å)12.4662 (4), 17.7213 (5), 7.4352 (2)
β (°) 96.658 (2)
V3)1631.49 (8)
Z4
Radiation typeMo Kα
µ (mm1)0.12
Crystal size (mm)0.52 × 0.30 × 0.26
Data collection
DiffractometerBruker APEXII CCD
diffractometer
Absorption correctionMulti-scan
(SADABS; Sheldrick, 2004)
Tmin, Tmax0.942, 0.970
No. of measured, independent and
observed [I > 2σ(I)] reflections
16092, 2808, 1961
Rint0.040
(sin θ/λ)max1)0.595
Refinement
R[F2 > 2σ(F2)], wR(F2), S 0.049, 0.174, 1.11
No. of reflections2808
No. of parameters237
H-atom treatmentH-atom parameters constrained
Δρmax, Δρmin (e Å3)0.18, 0.22

Computer programs: APEX2 (Bruker, 2007), SAINT (Bruker, 2007), SHELXS97 (Sheldrick, 2008), SHELXL97 (Sheldrick, 2008), Mercury (Macrae et al., 2008).

Hydrogen-bond geometry (Å, º) top
D—H···AD—HH···AD···AD—H···A
N1—H1···O20.861.922.641 (3)139.8
C16—H16A···O3i0.962.553.402 (4)148
Symmetry code: (i) x+1, y+1/2, z+3/2.
 

Acknowledgements

Dr. Wesley T. K. Chan, Professor Z. Y. Zhou, and the Hong Kong Polytechnic University are sincerely thanked for helping to collect the X-ray data.

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.  CrossRef Web of Science Google Scholar
First citationBernstein, J., Davis, R. E., Shimoni, L. & Chang, N.-L. (1995). Angew. Chem. Int. Ed. 341, 555–1573.  Google Scholar
First citationBruker (2007). APEX2 and SAINT, Bruker AXS Inc., Madison, Wisconsin, USA.  Google Scholar
First citationGowda, B. T., Sowmya, B. P., Kožíšek, J., Tokarčík, M. & Fuess, H. (2007a). Acta Cryst. E63, o2906.  Web of Science CSD CrossRef IUCr Journals Google Scholar
First citationGowda, B. T., Sowmya, B. P., Tokarčík, M., Kožíšek, J. & Fuess, H. (2007b). Acta Cryst. E63, o3326.  Web of Science CSD CrossRef IUCr Journals Google Scholar
First citationGowda, B. T., Sowmya, B. P., Tokarčík, M., Kožíšek, J. & Fuess, H. (2007c). Acta Cryst. E63, o3365.  Web of Science CSD CrossRef IUCr Journals Google Scholar
First citationKarle, I. L. & Brockway, L. O. (1944). J. Am. Chem. Soc. 66, 1974–1979.  CrossRef CAS Google Scholar
First citationMacrae, 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 CrossRef CAS IUCr Journals Google Scholar
First citationSaeed, S., Jasinski, J. P. & Butcher, R. J. (2011a). Acta Cryst. E67, o279.  Web of Science CSD CrossRef IUCr Journals Google Scholar
First citationSaeed, S., Rashid, N., Ng, S. W. & Tiekink, E. R. T. (2011b). Acta Cryst. E67, o1194.  Web of Science CSD CrossRef IUCr Journals Google Scholar
First citationSheldrick, G. M. (2004). SADABS. University of Göttingen, Germany.  Google Scholar
First citationSheldrick, G. M. (2008). Acta Cryst. A64, 112–122.  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