N-(2,5-Dichloro­phen­yl)benzene­sulfonamide

Gowda, B.T.; Foro, S.; Nirmala, P.G.; Fuess, H.

doi:10.1107/S1600536810004769

organic compounds

CRYSTALLOGRAPHIC
COMMUNICATIONS

ISSN: 2056-9890

Volume 66| Part 3| March 2010| Page o594

doi:10.1107/S1600536810004769

Open

access

N-(2,5-Dichlorophenyl)benzenesulfonamide

B. Thimme Gowda,^a ^* Sabine Foro,^b P. G. Nirmala ^a and Hartmut Fuess ^b

^aDepartment of Chemistry, Mangalore University, Mangalagangotri 574199, Mangalore, India, and ^bInstitute of Materials Science, Darmstadt University of Technology, Petersenstrasse 23, D-64287, Darmstadt, Germany
^*Correspondence e-mail: gowdabt@yahoo.com

(Received 21 January 2010; accepted 6 February 2010; online 13 February 2010)

In the title compound, C₁₂H₉Cl₂NO₂S, the conformation of the N—H bond is syn to the 2-chloro group and anti to the 3-chloro group of the aniline benzene ring. The molecule is bent at the S atom with a C—SO₂—NH—C torsion angle of 66.4 (2)°. The two rings form a dihedral angle of 73.3 (1)° and an intramolecular N—H⋯Cl hydrogen bond occurs. The crystal structure features chains linked by N—H⋯O hydrogen bonds.

Related literature

For the preparation of the title compound, see: Shetty & Gowda (2005 ). For our study of the effect of substituents on the structures of N-(aryl)arylsulfonamides, see: Gowda et al. (2009 , 2010 ). For related structures, see: Gelbrich et al. (2007 ); Perlovich et al. (2006 ).

Experimental

Crystal data

C₁₂H₉Cl₂NO₂S
M_r = 302.16
Monoclinic, P 2₁ /n
a = 9.595 (1) Å
b = 14.188 (2) Å
c = 10.424 (1) Å
β = 114.42 (2)°
V = 1292.1 (3) Å³
Z = 4
Mo Kα radiation
μ = 0.66 mm⁻¹
T = 299 K
0.44 × 0.40 × 0.32 mm

Data collection

Oxford Diffraction Xcalibur diffractometer with a Sapphire CCD Detector
Absorption correction: multi-scan (CrysAlis RED; Oxford Diffraction, 2009 $[Oxford Diffraction (2009). CrysAlis CCD and CrysAlis RED. Oxford Diffraction Ltd, Abingdon, England.]$ ) T_min = 0.761, T_max = 0.818
5199 measured reflections
2638 independent reflections
2225 reflections with I > 2σ(I)
R_int = 0.010

Refinement

R[F² > 2σ(F²)] = 0.031
wR(F²) = 0.086
S = 1.05
2638 reflections
167 parameters
1 restraint
H atoms treated by a mixture of independent and constrained refinement
Δρ_max = 0.23 e Å⁻³
Δρ_min = −0.34 e Å⁻³

Table 1
Hydrogen-bond geometry (Å, °)

D—H⋯A	D—H	H⋯A	D⋯A	D—H⋯A
N1—H1N⋯O1ⁱ	0.84 (1)	2.28 (1)	3.074 (2)	156 (2)
N1—H1N⋯Cl1	0.84 (1)	2.52 (2)	2.9795 (16)	115 (2)
Symmetry code: (i) -x, -y+1, -z+1.

Data collection: CrysAlis CCD (Oxford Diffraction, 2009 $[Oxford Diffraction (2009). CrysAlis CCD and CrysAlis RED. Oxford Diffraction Ltd, Abingdon, England.]$ ); cell refinement: CrysAlis RED (Oxford Diffraction, 2009 $[Oxford Diffraction (2009). CrysAlis CCD and CrysAlis RED. Oxford Diffraction Ltd, Abingdon, England.]$ ); data reduction: CrysAlis RED; program(s) used to solve structure: SHELXS97 (Sheldrick, 2008 ); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008); molecular graphics: PLATON (Spek, 2009 ); software used to prepare material for publication: SHELXL97.

Supporting information

Crystal structure: contains datablocks I, global. DOI: 10.1107/S1600536810004769/fl2289sup1.cif

Structure factors: contains datablock I. DOI: 10.1107/S1600536810004769/fl2289Isup2.hkl

checkCIF report

Comment top

As part of a study of substituent effects on the structures of N-(aryl)arylsulfonamides (Gowda et al., 2009; 2010), the structure of (I) has been determined. The conformation of the N—H bond is syn to the 2-chloro group and anti to the 3-chloro group in the aniline benzene ring (Fig. 1). The molecule is bent at the S atom with the C—SO₂—NH—C torsion angle of 66.4 (2)°, compared to the values of -62.1 (3)° and 60.7 (3)°, in the two molecules of N-(2,4-dichlorophenyl)benzenesulfonamide (II), -68.1 (3)° in N-(3,5-dichlorophenyl)benzenesulfonamide (III) (Gowda et al., 2010) and 62.7 (2)° in N-(2,5-dimethylphenyl)benzenesulfonamide (IV) (Gowda et al., 2009).

The sulfonyl benzene and the aniline benzene rings in (I) are tilted relative to each other by 73.3 (1)°, compared to the values of 70.8 (1)° (molecule 1) and 74.8 (1)° (molecule 2) in (II), 57.0 (1)° in (III) and 40.4 (1)° in (IV). The other bond parameters in (I) are similar to those observed in (II)-(IV) and other aryl sulfonamides (Perlovich et al., 2006; Gelbrich et al., 2007).

An intramolecular N—H···Cl hydrogen bond is observed. The crystal packing of molecules in (I) is via N—H···O(S) hydrogen bonds (Table 1, Fig. 2).

Related literature top

For the preparation of the title compound, see: Shetty & Gowda (2005). For our study of the effect of substituents on the structures of N-(aryl)arylsulfonamides, see: Gowda et al. (2009, 2010). For related structures, see: Gelbrich et al. (2007); Perlovich et al. (2006).

Experimental top

The solution of benzene (10 ml) in chloroform (40 ml) was treated dropwise with chlorosulfonic acid (25 ml) at 0 ° C. After the initial evolution of hydrogen chloride subsided, the reaction mixture was brought to room temperature and poured into crushed ice in a beaker. The chloroform layer was separated, washed with cold water and allowed to evaporate slowly. The residual benzenesulfonylchloride was treated with 2,5-dichloroaniline in the stoichiometric amounts and boiled for ten minutes. The reaction mixture was then cooled to room temperature and added to ice cold water (100 ml). The resultant solid (I) was filtered under suction and washed thoroughly with cold water. It was then recrystallized to constant melting point from dilute ethanol. The purity of the compound was checked and characterized by recording its infrared and NMR spectra (Shetty & Gowda, 2005). The rod like colorless single crystals used in X-ray diffraction studies were grown in ethanolic solution by evaporating it at room temperature.

Computing details top

Data collection: CrysAlis CCD (Oxford Diffraction, 2009); cell refinement: CrysAlis RED (Oxford Diffraction, 2009); data reduction: CrysAlis RED (Oxford Diffraction, 2009); program(s) used to solve structure: SHELXS97 (Sheldrick, 2008); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008); molecular graphics: PLATON (Spek, 2009); software used to prepare material for publication: SHELXL97 (Sheldrick, 2008).

Figures top

	Fig. 1. Molecular structure of (I), showing the atom labelling and displacement ellipsoids drawn at the 50% probability level.
	Fig. 2. Molecular packing of (I) with hydrogen bonding shown as dashed lines.

N-(2,5-Dichlorophenyl)benzenesulfonamide top

Crystal data top

C₁₂H₉Cl₂NO₂S	F(000) = 616
M_r = 302.16	D_x = 1.553 Mg m⁻³
Monoclinic, P2₁/n	Mo Kα radiation, λ = 0.71073 Å
Hall symbol: -P 2yn	Cell parameters from 2765 reflections
a = 9.595 (1) Å	θ = 2.7–27.8°
b = 14.188 (2) Å	µ = 0.66 mm⁻¹
c = 10.424 (1) Å	T = 299 K
β = 114.42 (2)°	Prism, colourless
V = 1292.1 (3) Å³	0.44 × 0.40 × 0.32 mm
Z = 4

Data collection top

Oxford Diffraction Xcalibur diffractometer with a Sapphire CCD Detector	2638 independent reflections
Radiation source: fine-focus sealed tube	2225 reflections with I > 2σ(I)
Graphite monochromator	R_int = 0.010
Rotation method data acquisition using ω and phi scans.	θ_max = 26.4°, θ_min = 2.7°
Absorption correction: multi-scan (CrysAlis RED; Oxford Diffraction, 2009)	h = −11→11
T_min = 0.761, T_max = 0.818	k = −13→17
5199 measured reflections	l = −7→13

Refinement top

Refinement on F²	Secondary atom site location: difference Fourier map
Least-squares matrix: full	Hydrogen site location: inferred from neighbouring sites
R[F² > 2σ(F²)] = 0.031	H atoms treated by a mixture of independent and constrained refinement
wR(F²) = 0.086	w = 1/[σ²(F_o²) + (0.0435P)² + 0.4815P] where P = (F_o² + 2F_c²)/3
S = 1.05	(Δ/σ)_max = 0.001
2638 reflections	Δρ_max = 0.23 e Å⁻³
167 parameters	Δρ_min = −0.34 e Å⁻³
1 restraint	Extinction correction: SHELXL, Fc^*=kFc[1+0.001xFc²λ³/sin(2θ)]^-1/4
Primary atom site location: structure-invariant direct methods	Extinction coefficient: 0.0316 (18)

Crystal data top

C₁₂H₉Cl₂NO₂S	V = 1292.1 (3) Å³
M_r = 302.16	Z = 4
Monoclinic, P2₁/n	Mo Kα radiation
a = 9.595 (1) Å	µ = 0.66 mm⁻¹
b = 14.188 (2) Å	T = 299 K
c = 10.424 (1) Å	0.44 × 0.40 × 0.32 mm
β = 114.42 (2)°

Data collection top

Oxford Diffraction Xcalibur diffractometer with a Sapphire CCD Detector	2638 independent reflections
Absorption correction: multi-scan (CrysAlis RED; Oxford Diffraction, 2009)	2225 reflections with I > 2σ(I)
T_min = 0.761, T_max = 0.818	R_int = 0.010
5199 measured reflections

Refinement top

R[F² > 2σ(F²)] = 0.031	1 restraint
wR(F²) = 0.086	H atoms treated by a mixture of independent and constrained refinement
S = 1.05	Δρ_max = 0.23 e Å⁻³
2638 reflections	Δρ_min = −0.34 e Å⁻³
167 parameters

Special details top

Experimental. Empirical absorption correction using spherical harmonics, implemented in SCALE3 ABSPACK scaling algorithm.

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 > 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

	x	y	z	U_iso*/U_eq
C1	−0.10881 (19)	0.57873 (12)	0.71058 (18)	0.0342 (4)
C2	−0.0940 (2)	0.61982 (15)	0.8359 (2)	0.0482 (5)
H2	−0.0255	0.5957	0.9217	0.058*
C3	−0.1826 (3)	0.69707 (18)	0.8311 (3)	0.0665 (7)
H3	−0.1732	0.7259	0.9145	0.080*
C4	−0.2852 (3)	0.73206 (17)	0.7038 (3)	0.0690 (7)
H4	−0.3452	0.7840	0.7016	0.083*
C5	−0.2991 (3)	0.69043 (18)	0.5800 (3)	0.0675 (7)
H5	−0.3688	0.7143	0.4943	0.081*
C6	−0.2105 (2)	0.61368 (15)	0.5821 (2)	0.0501 (5)
H6	−0.2188	0.5858	0.4984	0.060*
C7	0.27503 (19)	0.56534 (12)	0.85564 (18)	0.0338 (4)
C8	0.3535 (2)	0.64497 (13)	0.8424 (2)	0.0403 (4)
C9	0.4606 (2)	0.68914 (15)	0.9591 (2)	0.0515 (5)
H9	0.5129	0.7414	0.9479	0.062*
C10	0.4906 (2)	0.65644 (16)	1.0922 (2)	0.0528 (5)
H10	0.5621	0.6865	1.1713	0.063*
C11	0.4128 (2)	0.57828 (14)	1.10589 (19)	0.0429 (4)
C12	0.3074 (2)	0.53198 (13)	0.99013 (18)	0.0386 (4)
H12	0.2581	0.4785	1.0022	0.046*
N1	0.17095 (17)	0.51827 (11)	0.73345 (15)	0.0363 (3)
H1N	0.166 (2)	0.5403 (13)	0.6564 (14)	0.044*
O1	−0.05974 (16)	0.43413 (9)	0.58100 (13)	0.0443 (3)
O2	0.02450 (15)	0.42616 (9)	0.83833 (13)	0.0462 (3)
Cl1	0.31855 (6)	0.68832 (4)	0.67634 (6)	0.05849 (18)
Cl2	0.44864 (7)	0.53545 (5)	1.27273 (5)	0.06258 (19)
S1	0.00256 (5)	0.47941 (3)	0.71548 (4)	0.03304 (14)

Atomic displacement parameters (Å²) top

	U¹¹	U²²	U³³	U¹²	U¹³	U²³
C1	0.0319 (9)	0.0366 (9)	0.0350 (9)	−0.0051 (7)	0.0147 (7)	−0.0037 (7)
C2	0.0452 (11)	0.0609 (13)	0.0406 (10)	−0.0044 (9)	0.0200 (9)	−0.0115 (9)
C3	0.0580 (14)	0.0735 (16)	0.0783 (17)	−0.0084 (12)	0.0385 (13)	−0.0330 (14)
C4	0.0510 (13)	0.0540 (14)	0.109 (2)	0.0053 (11)	0.0400 (14)	−0.0137 (14)
C5	0.0563 (14)	0.0647 (15)	0.0737 (16)	0.0185 (12)	0.0190 (12)	0.0078 (13)
C6	0.0473 (11)	0.0551 (12)	0.0418 (11)	0.0082 (9)	0.0125 (9)	−0.0003 (9)
C7	0.0272 (8)	0.0366 (9)	0.0352 (9)	0.0026 (7)	0.0106 (7)	−0.0005 (7)
C8	0.0344 (9)	0.0397 (10)	0.0434 (10)	0.0020 (7)	0.0126 (8)	0.0064 (8)
C9	0.0441 (11)	0.0457 (11)	0.0587 (13)	−0.0129 (9)	0.0152 (9)	−0.0018 (9)
C10	0.0427 (11)	0.0575 (13)	0.0477 (11)	−0.0115 (9)	0.0083 (9)	−0.0106 (10)
C11	0.0342 (9)	0.0540 (12)	0.0351 (9)	0.0011 (8)	0.0090 (7)	−0.0019 (8)
C12	0.0333 (9)	0.0421 (10)	0.0376 (9)	−0.0028 (7)	0.0118 (8)	0.0004 (8)
N1	0.0340 (8)	0.0450 (9)	0.0306 (7)	−0.0030 (6)	0.0140 (6)	−0.0007 (6)
O1	0.0510 (8)	0.0428 (7)	0.0338 (7)	−0.0064 (6)	0.0123 (6)	−0.0099 (5)
O2	0.0507 (8)	0.0454 (7)	0.0357 (7)	−0.0107 (6)	0.0112 (6)	0.0078 (6)
Cl1	0.0530 (3)	0.0621 (3)	0.0535 (3)	−0.0064 (2)	0.0152 (2)	0.0205 (3)
Cl2	0.0564 (3)	0.0871 (4)	0.0342 (3)	−0.0090 (3)	0.0085 (2)	0.0007 (3)
S1	0.0356 (2)	0.0331 (2)	0.0272 (2)	−0.00569 (17)	0.00974 (17)	−0.00172 (16)

Geometric parameters (Å, º) top

C1—C6	1.383 (3)	C7—N1	1.419 (2)
C1—C2	1.383 (2)	C8—C9	1.377 (3)
C1—S1	1.7565 (18)	C8—Cl1	1.7343 (19)
C2—C3	1.375 (3)	C9—C10	1.375 (3)
C2—H2	0.9300	C9—H9	0.9300
C3—C4	1.377 (4)	C10—C11	1.377 (3)
C3—H3	0.9300	C10—H10	0.9300
C4—C5	1.375 (4)	C11—C12	1.379 (2)
C4—H4	0.9300	C11—Cl2	1.737 (2)
C5—C6	1.376 (3)	C12—H12	0.9300
C5—H5	0.9300	N1—S1	1.6430 (15)
C6—H6	0.9300	N1—H1N	0.844 (9)
C7—C12	1.388 (2)	O1—S1	1.4292 (13)
C7—C8	1.396 (2)	O2—S1	1.4254 (13)

C6—C1—C2	121.31 (18)	C7—C8—Cl1	119.74 (14)
C6—C1—S1	119.54 (14)	C10—C9—C8	120.44 (19)
C2—C1—S1	119.15 (15)	C10—C9—H9	119.8
C3—C2—C1	118.8 (2)	C8—C9—H9	119.8
C3—C2—H2	120.6	C9—C10—C11	118.67 (18)
C1—C2—H2	120.6	C9—C10—H10	120.7
C2—C3—C4	120.4 (2)	C11—C10—H10	120.7
C2—C3—H3	119.8	C10—C11—C12	121.72 (18)
C4—C3—H3	119.8	C10—C11—Cl2	119.63 (15)
C5—C4—C3	120.2 (2)	C12—C11—Cl2	118.65 (15)
C5—C4—H4	119.9	C11—C12—C7	119.90 (17)
C3—C4—H4	119.9	C11—C12—H12	120.1
C4—C5—C6	120.4 (2)	C7—C12—H12	120.1
C4—C5—H5	119.8	C7—N1—S1	123.65 (12)
C6—C5—H5	119.8	C7—N1—H1N	115.0 (15)
C5—C6—C1	118.9 (2)	S1—N1—H1N	110.3 (15)
C5—C6—H6	120.6	O2—S1—O1	119.31 (8)
C1—C6—H6	120.6	O2—S1—N1	107.60 (8)
C12—C7—C8	118.11 (16)	O1—S1—N1	104.80 (8)
C12—C7—N1	121.79 (16)	O2—S1—C1	108.27 (8)
C8—C7—N1	120.03 (15)	O1—S1—C1	109.23 (8)
C9—C8—C7	121.14 (18)	N1—S1—C1	106.97 (8)
C9—C8—Cl1	119.11 (15)

C6—C1—C2—C3	−0.1 (3)	C9—C10—C11—Cl2	179.98 (17)
S1—C1—C2—C3	−179.45 (16)	C10—C11—C12—C7	−1.5 (3)
C1—C2—C3—C4	0.7 (3)	Cl2—C11—C12—C7	179.16 (13)
C2—C3—C4—C5	−0.5 (4)	C8—C7—C12—C11	1.0 (3)
C3—C4—C5—C6	−0.2 (4)	N1—C7—C12—C11	178.02 (17)
C4—C5—C6—C1	0.7 (4)	C12—C7—N1—S1	45.9 (2)
C2—C1—C6—C5	−0.5 (3)	C8—C7—N1—S1	−137.14 (15)
S1—C1—C6—C5	178.75 (18)	C7—N1—S1—O2	−49.78 (17)
C12—C7—C8—C9	0.3 (3)	C7—N1—S1—O1	−177.73 (14)
N1—C7—C8—C9	−176.78 (18)	C7—N1—S1—C1	66.36 (16)
C12—C7—C8—Cl1	179.19 (13)	C6—C1—S1—O2	−146.50 (15)
N1—C7—C8—Cl1	2.1 (2)	C2—C1—S1—O2	32.81 (16)
C7—C8—C9—C10	−1.2 (3)	C6—C1—S1—O1	−15.12 (18)
Cl1—C8—C9—C10	179.95 (17)	C2—C1—S1—O1	164.19 (14)
C8—C9—C10—C11	0.7 (3)	C6—C1—S1—N1	97.79 (16)
C9—C10—C11—C12	0.6 (3)	C2—C1—S1—N1	−82.90 (16)

Hydrogen-bond geometry (Å, º) top

D—H···A	D—H	H···A	D···A	D—H···A
N1—H1N···O1ⁱ	0.84 (1)	2.28 (1)	3.074 (2)	156 (2)
N1—H1N···Cl1	0.84 (1)	2.52 (2)	2.9795 (16)	115 (2)

Symmetry code: (i) −x, −y+1, −z+1.

Experimental details

Crystal data
Chemical formula	C₁₂H₉Cl₂NO₂S
M_r	302.16
Crystal system, space group	Monoclinic, P2₁/n
Temperature (K)	299
a, b, c (Å)	9.595 (1), 14.188 (2), 10.424 (1)
β (°)	114.42 (2)
V (Å³)	1292.1 (3)
Z	4
Radiation type	Mo Kα
µ (mm⁻¹)	0.66
Crystal size (mm)	0.44 × 0.40 × 0.32

Data collection
Diffractometer	Oxford Diffraction Xcalibur diffractometer with a Sapphire CCD Detector
Absorption correction	Multi-scan (CrysAlis RED; Oxford Diffraction, 2009)
T_min, T_max	0.761, 0.818
No. of measured, independent and observed [I > 2σ(I)] reflections	5199, 2638, 2225
R_int	0.010
(sin θ/λ)_max (Å⁻¹)	0.625

Refinement
R[F² > 2σ(F²)], wR(F²), S	0.031, 0.086, 1.05
No. of reflections	2638
No. of parameters	167
No. of restraints	1
H-atom treatment	H atoms treated by a mixture of independent and constrained refinement
Δρ_max, Δρ_min (e Å⁻³)	0.23, −0.34

Computer programs: CrysAlis CCD (Oxford Diffraction, 2009), CrysAlis RED (Oxford Diffraction, 2009), SHELXS97 (Sheldrick, 2008), SHELXL97 (Sheldrick, 2008), PLATON (Spek, 2009).

Hydrogen-bond geometry (Å, º) top

D—H···A	D—H	H···A	D···A	D—H···A
N1—H1N···O1ⁱ	0.844 (9)	2.282 (12)	3.074 (2)	156.2 (19)
N1—H1N···Cl1	0.844 (9)	2.520 (19)	2.9795 (16)	115.3 (16)

Symmetry code: (i) −x, −y+1, −z+1.

References

Gelbrich, T., Hursthouse, M. B. & Threlfall, T. L. (2007). Acta Cryst. B63, 621–632. Web of Science CSD CrossRef IUCr Journals Google Scholar
Gowda, B. T., Foro, S., Nirmala, P. G. & Fuess, H. (2009). Acta Cryst. E65, o2763. Web of Science CrossRef IUCr Journals Google Scholar
Gowda, B. T., Foro, S., Nirmala, P. G. & Fuess, H. (2010). Acta Cryst. E66, o229. Web of Science CSD CrossRef IUCr Journals Google Scholar
Oxford Diffraction (2009). CrysAlis CCD and CrysAlis RED. Oxford Diffraction Ltd, Abingdon, England. Google Scholar
Perlovich, G. L., Tkachev, V. V., Schaper, K.-J. & Raevsky, O. A. (2006). Acta Cryst. E62, o780–o782. Web of Science CSD CrossRef IUCr Journals Google Scholar
Sheldrick, G. M. (2008). Acta Cryst. A64, 112–122. Web of Science CrossRef CAS IUCr Journals Google Scholar
Shetty, M. & Gowda, B. T. (2005). Z. Naturforsch. Teil A, 60, 113–120. CAS Google Scholar
Spek, 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.

CRYSTALLOGRAPHIC
COMMUNICATIONS

ISSN: 2056-9890

Volume 66| Part 3| March 2010| Page o594

doi:10.1107/S1600536810004769

Open

access