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

Journal logoCRYSTALLOGRAPHIC
COMMUNICATIONS
ISSN: 2056-9890

2-(Meth­oxy­carbon­yl)anilinium di­hydrogen phosphate

aMaterials Chemistry laboratory, Department of Chemistry, GC University, Lahore, Pakistan, and bDepartment of Chemistry, University of Otago, PO Box 56, Dunedin, New Zealand
*Correspondence e-mail: mnachemist@hotmail.com

(Received 29 June 2009; accepted 30 June 2009; online 4 July 2009)

The title compound, C8H10NO2+·H2PO4, is a derivative of the naturally occurring compound methyl­anthranilate. The asymmetric unit comprises the 2-(methoxy­carbon­yl)anilinium cation and the dihydrogen phosphate anion. In the cation, the dihedral angle between the benzene ring plane and that through the methyl ester substituent is 22.94 (9)°. In the crystal, adjacent cations and anions form dimers through N—H⋯O and O—H⋯O hydrogen bonds, respectively. Additional N—H⋯O and C—H⋯O contacts result in a network of cation and anion dimers stacked down the b axis.

Related literature

For thia­zine-related heterocycles see: Shafiq et al. (2009a[Shafiq, M., Tahir, M. N., Khan, I. U., Arshad, M. N. & Haider, Z. (2009a). Acta Cryst. E65, o1413.]). For related structures, see: Gel'mbol'dt et al. (2006[Gel'mbol'dt, V. O., Ganin, E. V., Koroeva, L. V., Minacheva, L. Kh., Sergienko, V. S. & Ennan, A. A. (2006). Zh. Neorg. Khim. 51, 237-244.]); Ma et al. (2005[Ma, Y.-Y., Yu, Y., Wu, Y.-F., Xiao, F.-P. & Jin, L.-F. (2005). Acta Cryst. E61, o3497-o3499.]); Shafiq et al. (2008[Shafiq, M., Tahir, M. N., Khan, I. U., Siddiqui, W. A. & Arshad, M. N. (2008). Acta Cryst. E64, o389.], 2009b[Shafiq, M., Tahir, M. N., Khan, I. U., Arshad, M. N. & Khan, M. H. (2009b). Acta Cryst. E65, o955.]).

[Scheme 1]

Experimental

Crystal data
  • C8H10NO2+·H2PO4

  • Mr = 249.16

  • Monoclinic, C 2/c

  • a = 20.939 (3) Å

  • b = 4.7880 (5) Å

  • c = 22.283 (4) Å

  • β = 114.970 (5)°

  • V = 2025.2 (5) Å3

  • Z = 8

  • Mo Kα radiation

  • μ = 0.29 mm−1

  • T = 296 K

  • 0.39 × 0.21 × 0.17 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 = 0.928, Tmax = 0.958

  • 10812 measured reflections

  • 2413 independent reflections

  • 2078 reflections with I > 2σ(I)

  • Rint = 0.035

Refinement
  • R[F2 > 2σ(F2)] = 0.037

  • wR(F2) = 0.102

  • S = 1.07

  • 2413 reflections

  • 153 parameters

  • H atoms treated by a mixture of independent and constrained refinement

  • Δρmax = 0.29 e Å−3

  • Δρmin = −0.48 e Å−3

Table 1
Hydrogen-bond geometry (Å, °)

D—H⋯A D—H H⋯A DA D—H⋯A
C4—H4⋯O5 0.93 2.68 3.387 (2) 133
C4—H4⋯O6 0.93 2.71 3.590 (2) 158
C3—H3⋯O2i 0.93 2.72 3.609 (2) 162
N1—H1A⋯O3ii 0.89 1.93 2.8218 (18) 178
N1—H1A⋯O5ii 0.89 2.68 3.190 (2) 118
N1—H1C⋯O3iii 0.89 2.01 2.9005 (18) 175
N1—H1B⋯O3iv 0.89 2.09 2.9400 (17) 160
O5—H5O⋯O6v 0.78 (2) 1.83 (2) 2.6021 (17) 170 (2)
O4—H4O⋯O6vi 0.72 (2) 1.88 (2) 2.6015 (17) 179 (2)
Symmetry codes: (i) [-x, y, -z+{\script{3\over 2}}]; (ii) [-x+{\script{1\over 2}}, y-{\script{1\over 2}}, -z+{\script{3\over 2}}]; (iii) [-x+{\script{1\over 2}}, y+{\script{1\over 2}}, -z+{\script{3\over 2}}]; (iv) [x, -y+1, z+{\script{1\over 2}}]; (v) x, y+1, z; (vi) -x, -y+1, -z+1.

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: SHELXTL (Sheldrick, 2008[Sheldrick, G. M. (2008). Acta Cryst. A64, 112-122.]) and Mercury (Macrae et al., 2006[Macrae, C. F., Edgington, P. R., McCabe, P., Pidcock, E., Shields, G. P., Taylor, R., Towler, M. & van de Streek, J. (2006). J. Appl. Cryst. 39, 453-457.]); software used to prepare material for publication: SHELXL97, enCIFer (Allen et al., 2004[Allen, F. H., Johnson, O., Shields, G. P., Smith, B. R. & Towler, M. (2004). J. Appl. Cryst. 37, 335-338.]), PLATON (Spek, 2009[Spek, A. L. (2009). Acta Cryst. D65, 148-155.]) and publCIF (Westrip, 2009[Westrip, S. P. (2009). publCIF. In preparation.]).

Supporting information


Comment top

Methylanthranilite is a naturally occurring compound which has been used in food flavoring, as a fragrance additive and a bird repellent. Our group has been involved in the synthesis of heterocyclic molecules related to benzothiazine (Shafiq et al., 2009a) in which the title compound has been used as a starting material (Shafiq et al., 2008; Shafiq et al., 2009b). Herein we report the structure of title compound which was obtained during the synthesis of methylanthranilate Schiff base derivatives.

The asymmetric unit comprises the 2-(methoxycarbonyl)anilinium cation and the dihydrogen phosphate anion linked by bifurcated C4–H4···O5 and C4—H4···O6 interactions, Fig. 1. In the cation the dihedral angle between the C1···C6 benzene ring plane and that through the C2,C7(O1),O2,C8 atoms of the methyl ester substituent is 22.94 (9) °. Bond distances within the molecule are normal and similar to those observed in comparable structures (Gel'mbol'dt et al., 2006; Ma et al., 2005). In the crystal, adjacent cations and anions form dimers through N1—H1A···O1 and O4—H4O···O6 hydrogen bonds respectively, Fig. 2. Additional N—H···O and C—H···O contacts result in a network of cation and anion dimers stacked down the b axis, Fig. 3.

Related literature top

For thiazine-related heterocycles see: Shafiq et al. (2009a). For related structures, see: Gel'mbol'dt et al. (2006); Ma et al. (2005); Shafiq et al. (2008, 2009b)

Experimental top

The title compound was obtained during the synthesis of Schiff base of methyl anthranilate. Methyl anthranilite (0.5 g, 0.0 mol) was dissolved in methanol (5 ml). A few drops of polyphosphoric acid were added to the above solution to precipitate the product which was recrystalized from methanol.

Refinement top

The H atoms bound to N1, O4 and O5 were located in a difference Fourier map and their coordinates were refined with Uiso= 1.5Ueq (N) and 1.2Ueq (O). All other H-atoms were placed in calculated positions and refined using a riding model with d(C—H) = 0.93 Å, Uiso = 1.2Ueq (C) for aromatic and 0.96 Å, Uiso = 1.5Ueq (C) for CH3 H atoms.

Computing details top

Data collection: APEX2 (Bruker, 2007); cell refinement: SAINT (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: SHELXTL (Sheldrick, 2008) and Mercury (Macrae et al., 2006); software used to prepare material for publication: SHELXL97 (Sheldrick, 2008), enCIFer (Allen et al., 2004), PLATON (Spek, 2009) and publCIF (Westrip, 2009).

Figures top
[Figure 1] Fig. 1. The asymmetric unit of (I) with displacement ellipsoids for the non-hydrogen atoms drawn at the 50% probability level. Hydrogen bonds are drawn as dashed lines.
[Figure 2] Fig. 2. Dimers formed by the cations and anions in the structure of (I) with hydrogen bonds drawn as dashed lines.
[Figure 3] Fig. 3. Crystal packing of (I) viewed down the b axis
2-(Methoxycarbonyl)anilinium dihydrogen phosphate top
Crystal data top
C8H10NO2+·H2PO4F(000) = 1040
Mr = 249.16Dx = 1.634 Mg m3
Monoclinic, C2/cMo Kα radiation, λ = 0.71073 Å
Hall symbol: -C 2ycCell parameters from 5124 reflections
a = 20.939 (3) Åθ = 2.2–27.9°
b = 4.7880 (5) ŵ = 0.29 mm1
c = 22.283 (4) ÅT = 296 K
β = 114.970 (5)°Needle, colourless
V = 2025.2 (5) Å30.39 × 0.21 × 0.17 mm
Z = 8
Data collection top
Bruker Kappa APEXII CCD
diffractometer
2413 independent reflections
Radiation source: fine-focus sealed tube2078 reflections with I > 2σ(I)
Graphite monochromatorRint = 0.035
ϕ and ω scansθmax = 27.9°, θmin = 3.5°
Absorption correction: multi-scan
(SADABS; Bruker, 2005)
h = 2727
Tmin = 0.928, Tmax = 0.958k = 46
10812 measured reflectionsl = 2927
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)] = 0.037Hydrogen site location: inferred from neighbouring sites
wR(F2) = 0.102H atoms treated by a mixture of independent and constrained refinement
S = 1.07 w = 1/[σ2(Fo2) + (0.0575P)2 + 1.6713P]
where P = (Fo2 + 2Fc2)/3
2413 reflections(Δ/σ)max = 0.001
153 parametersΔρmax = 0.29 e Å3
0 restraintsΔρmin = 0.48 e Å3
Crystal data top
C8H10NO2+·H2PO4V = 2025.2 (5) Å3
Mr = 249.16Z = 8
Monoclinic, C2/cMo Kα radiation
a = 20.939 (3) ŵ = 0.29 mm1
b = 4.7880 (5) ÅT = 296 K
c = 22.283 (4) Å0.39 × 0.21 × 0.17 mm
β = 114.970 (5)°
Data collection top
Bruker Kappa APEXII CCD
diffractometer
2413 independent reflections
Absorption correction: multi-scan
(SADABS; Bruker, 2005)
2078 reflections with I > 2σ(I)
Tmin = 0.928, Tmax = 0.958Rint = 0.035
10812 measured reflections
Refinement top
R[F2 > 2σ(F2)] = 0.0370 restraints
wR(F2) = 0.102H atoms treated by a mixture of independent and constrained refinement
S = 1.07Δρmax = 0.29 e Å3
2413 reflectionsΔρmin = 0.48 e Å3
153 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
N10.24287 (7)0.4968 (3)0.93401 (6)0.0200 (3)
H1A0.26950.34430.94730.030*
H1B0.21270.50140.95260.030*
H1C0.27020.64780.94600.030*
C10.20379 (8)0.4920 (3)0.86203 (7)0.0202 (3)
C20.14685 (8)0.3118 (3)0.83134 (7)0.0227 (3)
C30.11163 (9)0.3157 (4)0.76239 (8)0.0300 (4)
H30.07300.19960.74120.036*
C40.13337 (10)0.4893 (4)0.72527 (9)0.0326 (4)
H40.11020.48640.67930.039*
C50.18948 (10)0.6671 (4)0.75648 (9)0.0322 (4)
H50.20380.78570.73150.039*
C60.22462 (9)0.6700 (4)0.82496 (8)0.0273 (4)
H60.26220.79160.84590.033*
C70.12565 (8)0.1075 (3)0.86989 (8)0.0225 (3)
C80.03453 (11)0.1887 (5)0.86660 (11)0.0433 (5)
H8A0.06090.17950.91380.065*
H8B0.04020.37000.85110.065*
H8C0.01440.15660.85550.065*
O10.16391 (6)0.0261 (3)0.92428 (6)0.0273 (3)
O20.05989 (7)0.0218 (3)0.83567 (7)0.0380 (3)
P10.10739 (2)0.56312 (8)0.531833 (19)0.01826 (13)
O30.17510 (6)0.5066 (2)0.52576 (6)0.0248 (3)
O40.05239 (6)0.6781 (3)0.46425 (6)0.0262 (3)
H4O0.0163 (12)0.681 (5)0.4598 (10)0.031*
O50.12078 (7)0.8011 (3)0.58427 (6)0.0323 (3)
H5O0.1063 (13)0.948 (5)0.5709 (11)0.039*
O60.07879 (6)0.3146 (2)0.55400 (6)0.0255 (3)
Atomic displacement parameters (Å2) top
U11U22U33U12U13U23
N10.0199 (6)0.0202 (6)0.0191 (6)0.0008 (5)0.0075 (5)0.0015 (5)
C10.0202 (7)0.0201 (7)0.0196 (7)0.0040 (6)0.0076 (6)0.0003 (6)
C20.0230 (8)0.0219 (7)0.0215 (7)0.0022 (6)0.0079 (6)0.0005 (6)
C30.0277 (9)0.0334 (9)0.0222 (8)0.0011 (7)0.0038 (6)0.0010 (7)
C40.0353 (10)0.0407 (10)0.0194 (8)0.0074 (8)0.0091 (7)0.0046 (7)
C50.0365 (10)0.0354 (9)0.0294 (9)0.0048 (8)0.0185 (7)0.0085 (8)
C60.0277 (8)0.0260 (8)0.0295 (8)0.0016 (7)0.0134 (7)0.0009 (7)
C70.0219 (7)0.0202 (7)0.0235 (8)0.0008 (6)0.0077 (6)0.0031 (6)
C80.0388 (11)0.0397 (11)0.0495 (12)0.0184 (9)0.0167 (9)0.0013 (9)
O10.0257 (6)0.0293 (6)0.0241 (6)0.0007 (5)0.0078 (5)0.0036 (5)
O20.0268 (7)0.0436 (8)0.0329 (7)0.0137 (6)0.0022 (5)0.0073 (6)
P10.0173 (2)0.0154 (2)0.0226 (2)0.00185 (14)0.00890 (16)0.00206 (14)
O30.0181 (6)0.0250 (6)0.0324 (6)0.0032 (4)0.0118 (5)0.0025 (5)
O40.0179 (5)0.0338 (7)0.0261 (6)0.0029 (5)0.0086 (5)0.0069 (5)
O50.0466 (8)0.0189 (6)0.0277 (6)0.0072 (5)0.0122 (6)0.0001 (5)
O60.0234 (6)0.0186 (5)0.0363 (6)0.0010 (4)0.0142 (5)0.0060 (5)
Geometric parameters (Å, º) top
N1—C11.4609 (19)C6—H60.9300
N1—H1A0.8900C7—O11.2010 (19)
N1—H1B0.8900C7—O21.326 (2)
N1—H1C0.8900C8—O21.443 (2)
C1—C61.379 (2)C8—H8A0.9600
C1—C21.395 (2)C8—H8B0.9600
C2—C31.396 (2)C8—H8C0.9600
C2—C71.488 (2)P1—O31.5045 (12)
C3—C41.379 (3)P1—O61.5062 (12)
C3—H30.9300P1—O41.5597 (12)
C4—C51.378 (3)P1—O51.5702 (13)
C4—H40.9300O4—H4O0.72 (2)
C5—C61.386 (2)O5—H5O0.78 (2)
C5—H50.9300
C1—N1—H1A109.5C1—C6—C5119.85 (16)
C1—N1—H1B109.5C1—C6—H6120.1
H1A—N1—H1B109.5C5—C6—H6120.1
C1—N1—H1C109.5O1—C7—O2124.62 (16)
H1A—N1—H1C109.5O1—C7—C2124.15 (15)
H1B—N1—H1C109.5O2—C7—C2111.21 (14)
C6—C1—C2120.64 (15)O2—C8—H8A109.5
C6—C1—N1118.39 (14)O2—C8—H8B109.5
C2—C1—N1120.97 (14)H8A—C8—H8B109.5
C1—C2—C3118.45 (15)O2—C8—H8C109.5
C1—C2—C7121.69 (14)H8A—C8—H8C109.5
C3—C2—C7119.77 (15)H8B—C8—H8C109.5
C4—C3—C2120.91 (17)C7—O2—C8116.33 (15)
C4—C3—H3119.5O3—P1—O6114.06 (7)
C2—C3—H3119.5O3—P1—O4108.44 (7)
C5—C4—C3119.79 (16)O6—P1—O4111.21 (7)
C5—C4—H4120.1O3—P1—O5108.56 (7)
C3—C4—H4120.1O6—P1—O5107.47 (7)
C4—C5—C6120.33 (17)O4—P1—O5106.83 (7)
C4—C5—H5119.8P1—O4—H4O116.4 (17)
C6—C5—H5119.8P1—O5—H5O117.1 (18)
C6—C1—C2—C30.1 (2)N1—C1—C6—C5178.83 (15)
N1—C1—C2—C3179.80 (15)C4—C5—C6—C10.7 (3)
C6—C1—C2—C7176.75 (15)C1—C2—C7—O121.1 (2)
N1—C1—C2—C73.1 (2)C3—C2—C7—O1155.53 (17)
C1—C2—C3—C41.3 (3)C1—C2—C7—O2160.61 (16)
C7—C2—C3—C4175.43 (16)C3—C2—C7—O222.8 (2)
C2—C3—C4—C51.7 (3)O1—C7—O2—C81.5 (3)
C3—C4—C5—C60.7 (3)C2—C7—O2—C8176.80 (16)
C2—C1—C6—C51.1 (3)
Hydrogen-bond geometry (Å, º) top
D—H···AD—HH···AD···AD—H···A
C4—H4···O50.932.683.387 (2)133
C4—H4···O60.932.713.590 (2)158
C3—H3···O2i0.932.723.609 (2)162
N1—H1A···O3ii0.891.932.8218 (18)178
N1—H1A···O5ii0.892.683.190 (2)118
N1—H1C···O3iii0.892.012.9005 (18)175
N1—H1B···O3iv0.892.092.9400 (17)160
O5—H5O···O6v0.78 (2)1.83 (2)2.6021 (17)170 (2)
O4—H4O···O6vi0.72 (2)1.88 (2)2.6015 (17)179 (2)
Symmetry codes: (i) x, y, z+3/2; (ii) x+1/2, y1/2, z+3/2; (iii) x+1/2, y+1/2, z+3/2; (iv) x, y+1, z+1/2; (v) x, y+1, z; (vi) x, y+1, z+1.

Experimental details

Crystal data
Chemical formulaC8H10NO2+·H2PO4
Mr249.16
Crystal system, space groupMonoclinic, C2/c
Temperature (K)296
a, b, c (Å)20.939 (3), 4.7880 (5), 22.283 (4)
β (°) 114.970 (5)
V3)2025.2 (5)
Z8
Radiation typeMo Kα
µ (mm1)0.29
Crystal size (mm)0.39 × 0.21 × 0.17
Data collection
DiffractometerBruker Kappa APEXII CCD
diffractometer
Absorption correctionMulti-scan
(SADABS; Bruker, 2005)
Tmin, Tmax0.928, 0.958
No. of measured, independent and
observed [I > 2σ(I)] reflections
10812, 2413, 2078
Rint0.035
(sin θ/λ)max1)0.658
Refinement
R[F2 > 2σ(F2)], wR(F2), S 0.037, 0.102, 1.07
No. of reflections2413
No. of parameters153
H-atom treatmentH atoms treated by a mixture of independent and constrained refinement
Δρmax, Δρmin (e Å3)0.29, 0.48

Computer programs: APEX2 (Bruker, 2007), SAINT (Bruker, 2007), SHELXS97 (Sheldrick, 2008), SHELXTL (Sheldrick, 2008) and Mercury (Macrae et al., 2006), SHELXL97 (Sheldrick, 2008), enCIFer (Allen et al., 2004), PLATON (Spek, 2009) and publCIF (Westrip, 2009).

Hydrogen-bond geometry (Å, º) top
D—H···AD—HH···AD···AD—H···A
C4—H4···O50.932.683.387 (2)133.1
C4—H4···O60.932.713.590 (2)157.8
C3—H3···O2i0.932.723.609 (2)161.5
N1—H1A···O3ii0.891.932.8218 (18)178.3
N1—H1A···O5ii0.892.683.190 (2)117.6
N1—H1C···O3iii0.892.012.9005 (18)174.8
N1—H1B···O3iv0.892.092.9400 (17)159.8
O5—H5O···O6v0.78 (2)1.83 (2)2.6021 (17)170 (2)
O4—H4O···O6vi0.72 (2)1.88 (2)2.6015 (17)179 (2)
Symmetry codes: (i) x, y, z+3/2; (ii) x+1/2, y1/2, z+3/2; (iii) x+1/2, y+1/2, z+3/2; (iv) x, y+1, z+1/2; (v) x, y+1, z; (vi) x, y+1, z+1.
 

Acknowledgements

MS & MNA acknowledge the Higher Education Commission of Pakistan for providing PhD Scholarships under the Indigenous 5000 PhD fellowship program.

References

First citationAllen, F. H., Johnson, O., Shields, G. P., Smith, B. R. & Towler, M. (2004). J. Appl. Cryst. 37, 335–338.  Web of Science CrossRef CAS IUCr Journals Google Scholar
First citationBruker (2005). SADABS. Bruker AXS Inc., Madison, Wisconsin, USA.  Google Scholar
First citationBruker (2007). APEX2 and SAINT. Bruker AXS Inc., Madison, Wisconsin, USA.  Google Scholar
First citationGel'mbol'dt, V. O., Ganin, E. V., Koroeva, L. V., Minacheva, L. Kh., Sergienko, V. S. & Ennan, A. A. (2006). Zh. Neorg. Khim. 51, 237–244.  CAS Google Scholar
First citationMa, Y.-Y., Yu, Y., Wu, Y.-F., Xiao, F.-P. & Jin, L.-F. (2005). Acta Cryst. E61, o3497–o3499.  Web of Science CSD CrossRef IUCr Journals Google Scholar
First citationMacrae, C. F., Edgington, P. R., McCabe, P., Pidcock, E., Shields, G. P., Taylor, R., Towler, M. & van de Streek, J. (2006). J. Appl. Cryst. 39, 453–457.  Web of Science CrossRef CAS IUCr Journals Google Scholar
First citationShafiq, M., Tahir, M. N., Khan, I. U., Arshad, M. N. & Haider, Z. (2009a). Acta Cryst. E65, o1413.  Web of Science CSD CrossRef IUCr Journals Google Scholar
First citationShafiq, M., Tahir, M. N., Khan, I. U., Arshad, M. N. & Khan, M. H. (2009b). Acta Cryst. E65, o955.  Web of Science CSD CrossRef IUCr Journals Google Scholar
First citationShafiq, M., Tahir, M. N., Khan, I. U., Siddiqui, W. A. & Arshad, M. N. (2008). Acta Cryst. E64, o389.  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 citationWestrip, S. P. (2009). publCIF. In preparation.  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