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

Journal logoCRYSTALLOGRAPHIC
COMMUNICATIONS
ISSN: 2056-9890
Volume 68| Part 11| November 2012| Pages o3101-o3102

4-(2-Chloro­phenyl­amino)-pent-3-en-2-one

aDepartment of Chemistry, University of the Free State, PO Box 339, Bloemfontein, 9300, South Africa
*Correspondence e-mail: ventergjs@ufs.ac.za

(Received 21 September 2012; accepted 8 October 2012; online 13 October 2012)

In the title compound, C11H12ClNO, intra­molecular N—H⋯O hydrogen bonding is present. The dihedral angle between the benzene ring and the pentenone unit is 46.52 (5)°. In the crystal, C—H⋯O inter­actions between hydrogen atoms of the aryl moiety and two separate oxygen atoms occur, leading to a three-dimensional network.

Related literature

For synthetic background and similar compounds, see: Shaheen et al. (2006[Shaheen, F., Marchio, L., Badshah, A. & Khosa, M. K. (2006). Acta Cryst. E62, o873-o874.]); Venter et al. (2010[Venter, G. J. S., Steyl, G. & Roodt, A. (2010). Acta Cryst. E66, o3011-o3012.], 2012b[Venter, G. J. S., Steyl, G. & Roodt, A. (2012b). Acta Cryst. E68, o2930-o2931.]). For applications, see: Brink et al. (2010[Brink, A., Visser, H. G., Steyl, G. & Roodt, A. (2010). Dalton Trans. 39, 5572-5578.]); Pyżuk et al. (1993[Pyżuk, W., Krówczynsk, A. & Górecka, E. (1993). Mol. Cryst. Liq. Cryst. 237, 75-84.]); Roodt & Steyn (2000[Roodt, A. & Steyn, G. J. J. (2000). Recent Research Developments in Inorganic Chemistry. Vol. 2, pp. 1-23. Trivandrum: Transworld Research Network.]); Tan et al. (2008[Tan, H. Y., Loke, W. K., Tan, Y. T. & Nguyen, N.-T. (2008). Lab Chip, 8, 885-891.]); Xia et al. (2008[Xia, M., Wu, B. & Xiang, G. (2008). J. Fluor. Chem. 129, 402-408.]). For related ligand systems, see: Damoense et al. (1994[Damoense, L. J., Purcell, W., Roodt, A. & Leipoldt, J. G. (1994). Rhodium Express, 5, 10-13.]), Venter et al. (2012a[Venter, G. J. S., Steyl, G. & Roodt, A. (2012a). Acta Cryst. E68, m666-m667.]).

[Scheme 1]

Experimental

Crystal data
  • C11H12ClNO

  • Mr = 209.67

  • Orthorhombic, P 21 21 21

  • a = 7.3264 (3) Å

  • b = 8.7103 (4) Å

  • c = 16.1960 (7) Å

  • V = 1033.55 (8) Å3

  • Z = 4

  • Mo Kα radiation

  • μ = 0.33 mm−1

  • T = 100 K

  • 0.6 × 0.42 × 0.21 mm

Data collection
  • Bruker APEXII CCD area-detector diffractometer

  • Absorption correction: multi-scan (SADABS; Bruker, 2004[Bruker (2004). SAINT-Plus and SADABS. Bruker AXS Inc., Madison, Wisconsin, USA.]) Tmin = 0.825, Tmax = 0.933

  • 17399 measured reflections

  • 2259 independent reflections

  • 2211 reflections with I > 2σ(I)

  • Rint = 0.032

Refinement
  • R[F2 > 2σ(F2)] = 0.025

  • wR(F2) = 0.068

  • S = 1.06

  • 2259 reflections

  • 126 parameters

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

  • Δρmax = 0.21 e Å−3

  • Δρmin = −0.24 e Å−3

  • Absolute structure: Flack (1983[Flack, H. D. (1983). Acta Cryst. A39, 876-881.]), 932 Friedel pairs

  • Flack parameter: 0.01 (5)

Table 1
Hydrogen-bond geometry (Å, °)

D—H⋯A D—H H⋯A DA D—H⋯A
N11—H11⋯O12 0.82 1.95 2.6317 (16) 139
C113—H113⋯O12i 0.95 2.42 3.3536 (18) 166
C115—H115⋯O12ii 0.95 2.43 3.3217 (18) 157
Symmetry codes: (i) [x-{\script{1\over 2}}, -y+{\script{1\over 2}}, -z+1]; (ii) x, y+1, z.

Data collection: APEX2 (Bruker, 2005[Bruker (2005). APEX2. Bruker AXS Inc., Madison, Wisconsin, USA.]); cell refinement: SAINT-Plus (Bruker, 2004[Bruker (2004). SAINT-Plus and SADABS. Bruker AXS Inc., Madison, Wisconsin, USA.]); data reduction: SAINT-Plus; 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: DIAMOND (Brandenburg & Putz, 2005[Brandenburg, K. & Putz, H. (2005). DIAMOND. Crystal Impact GbR, Bonn, Germany.]); software used to prepare material for publication: WinGX (Farrugia, 1999[Farrugia, L. J. (1999). J. Appl. Cryst. 32, 837-838.]).

Supporting information


Comment top

The β-diketone compound AcacH (acetylacetone; or when coordinated acetylacetonato, acac-) has been studied extensively, with a multitude of derivatives synthesized to date. One such derivative type, known as enaminoketones, contains both nitrogen and oxygen atoms with an unsaturated CC bond, and is of interest in various fields including liquid crystals [Pyżuk et al. (1993)], fluorescence studies [Xia et al. (2008)], medicine [Tan et al. (2008)] and catalysis [Roodt & Steyn (2000); Brink et al. (2010)].

The title compound (Fig. 1) crystallizes in the orthorhombic space group P212121 with Z = 4. This enaminoketone is a derivative of 4-(phenylamino)pent-3-en-2-one [PhonyH; Shaheen et al. (2006)]. Bond distances differ significantly from compounds coordinated to rhodium [Venter et al. (2012a); Damoense et al. (1994)], but share characteristics with other enaminoketones of this type [Venter et al. (2010; 2012b). An unsaturated bond in the pentenone backbone is indicated by the difference in distance between the C2C3 bond [1.379 (2) Å] and the C3–C4 bond [1.428 (2) Å]. The distance, N11···O12, is greatly increased (~ 0.2 Å) upon coordination. Intramolecular N11—H11···O12 bonding (D—A distance = 2.632 (2) Å was observed, as well as intermolecular interactions for C113—H113···O12i [i = x-0.5, 0.5-y, 1-z; distance = 3.3536 (18) Å] and C115—H115···O12ii [ii = x, y+1, z; distance = 3.3217 (18) Å]. These interactions are illustrated in Fig. 2. The dihedral angle between the benzene ring and pentenone moieties is 46.52 (5)° and is dependent on the position of the substituent on the benzene ring, where para substituents usually display the smallest angles (Venter et al., 2010).

Related literature top

For synthetic background and similar compounds, see: Shaheen et al. (2006); Venter et al. (2010, 2012b). For applications, see: Brink et al. (2010); Pyżuk et al. (1993); Roodt & Steyn (2000); Tan et al. (2008); Xia et al. (2008). For related ligand systems, see: Damoense et al. (1994), Venter et al. (2012a).

Experimental top

A solution of acetylacetone (11.07 g, 0.1106 mol), 2-chloro-aniline (10.73 g, 0.1008 mol) and 2 drops of H2SO4 (conc.) in 150 ml benzene was refluxed for 6 h in a Dean-Stark trap, filtered and left to crystallize. Crystals suitable for X-ray diffraction were obtained in 17.86 g (94.32%) yield. This compound is stable in air and light over a period of several months.

Refinement top

The methyl and aromatic H atoms were placed in geometrically idealized positions and constrained to ride on their parent atoms, with C—H = 0.95 Å and 0.98 Å and Uiso(H) = 1.5Ueq(C) and 1.2Ueq(C), respectively. The methyl groups were generated to fit the difference electron density and the groups were then refined as rigid rotors.

Computing details top

Data collection: APEX2 (Bruker, 2005); cell refinement: SAINT-Plus (Bruker, 2004); data reduction: SAINT-Plus (Bruker, 2004); program(s) used to solve structure: SHELXS97 (Sheldrick, 2008); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008); molecular graphics: DIAMOND (Brandenburg & Putz, 2005); software used to prepare material for publication: WinGX (Farrugia, 1999).

Figures top
[Figure 1] Fig. 1. Molecular structure of the title compound. Displacement ellipsoids are drawn at the 50% probability level. Hydrogen atoms are shown as spheres of arbitrary radius.
[Figure 2] Fig. 2. Partially filled unit cell illustrating the intra- and intermolecular hydrogen bonding interactions in the title compound, indicated with dashed lines.
4-(2-Chlorophenylamino)-pent-3-en-2-one top
Crystal data top
C11H12ClNOF(000) = 440
Mr = 209.67Dx = 1.347 Mg m3
Orthorhombic, P212121Mo Kα radiation, λ = 0.71073 Å
Hall symbol: P 2ac 2abCell parameters from 5717 reflections
a = 7.3264 (3) Åθ = 2.7–28.3°
b = 8.7103 (4) ŵ = 0.33 mm1
c = 16.1960 (7) ÅT = 100 K
V = 1033.55 (8) Å3Cuboid, yellow
Z = 40.6 × 0.42 × 0.21 mm
Data collection top
Bruker APEXII CCD area-detector
diffractometer
2259 independent reflections
Radiation source: fine-focus sealed tube2211 reflections with I > 2σ(I)
Graphite monochromatorRint = 0.032
ϕ and ω scansθmax = 27.0°, θmin = 2.5°
Absorption correction: multi-scan
(SADABS; Bruker, 2004)
h = 99
Tmin = 0.825, Tmax = 0.933k = 1111
17399 measured reflectionsl = 2019
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)] = 0.025H atoms treated by a mixture of independent and constrained refinement
wR(F2) = 0.068 w = 1/[σ2(Fo2) + (0.0376P)2 + 0.2837P]
where P = (Fo2 + 2Fc2)/3
S = 1.06(Δ/σ)max = 0.013
2259 reflectionsΔρmax = 0.21 e Å3
126 parametersΔρmin = 0.24 e Å3
0 restraintsAbsolute structure: Flack (1983), 932 Friedel pairs
Primary atom site location: structure-invariant direct methodsAbsolute structure parameter: 0.01 (5)
Crystal data top
C11H12ClNOV = 1033.55 (8) Å3
Mr = 209.67Z = 4
Orthorhombic, P212121Mo Kα radiation
a = 7.3264 (3) ŵ = 0.33 mm1
b = 8.7103 (4) ÅT = 100 K
c = 16.1960 (7) Å0.6 × 0.42 × 0.21 mm
Data collection top
Bruker APEXII CCD area-detector
diffractometer
2259 independent reflections
Absorption correction: multi-scan
(SADABS; Bruker, 2004)
2211 reflections with I > 2σ(I)
Tmin = 0.825, Tmax = 0.933Rint = 0.032
17399 measured reflections
Refinement top
R[F2 > 2σ(F2)] = 0.025H atoms treated by a mixture of independent and constrained refinement
wR(F2) = 0.068Δρmax = 0.21 e Å3
S = 1.06Δρmin = 0.24 e Å3
2259 reflectionsAbsolute structure: Flack (1983), 932 Friedel pairs
126 parametersAbsolute structure parameter: 0.01 (5)
0 restraints
Special details top

Geometry. All s.u.'s (except the s.u. in the dihedral angle between two l.s. planes) are estimated using the full covariance matrix. The cell s.u.'s are taken into account individually in the estimation of s.u.'s in distances, angles and torsion angles; correlations between s.u.'s in cell parameters are only used when they are defined by crystal symmetry. An approximate (isotropic) treatment of cell s.u.'s is used for estimating s.u.'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 > 2σ(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
Cl120.00235 (5)0.20519 (4)0.531562 (19)0.02339 (10)
N110.21805 (15)0.28866 (14)0.67897 (7)0.0174 (2)
H110.2500 (8)0.209 (2)0.6556 (6)0.027 (5)*
O120.33003 (14)0.00171 (12)0.68371 (6)0.02136 (18)
C30.24678 (18)0.14426 (16)0.80149 (9)0.0178 (3)
H30.23620.14110.85990.021*
C20.20915 (17)0.28095 (16)0.76209 (8)0.0169 (3)
C1110.18055 (18)0.41335 (16)0.62662 (8)0.0166 (3)
C1160.2464 (2)0.56091 (16)0.64159 (9)0.0197 (3)
H1160.31910.57970.68910.024*
C40.3006 (2)0.00740 (18)0.75983 (9)0.02136 (18)
C1130.04201 (19)0.50725 (19)0.49974 (9)0.0229 (3)
H1130.02640.48810.4510.027*
C50.3168 (2)0.13853 (17)0.80936 (9)0.0227 (3)
H5A0.20320.19740.80470.034*
H5B0.3390.11310.86740.034*
H5C0.41850.20.78810.034*
C1120.08035 (18)0.38927 (17)0.55421 (9)0.0184 (3)
C1150.20717 (19)0.68074 (17)0.58791 (9)0.0226 (3)
H1150.25050.78120.59960.027*
C10.1554 (2)0.41966 (16)0.81135 (9)0.0203 (3)
H1A0.26280.48450.82050.03*
H1B0.10560.38710.86470.03*
H1C0.06270.4780.78110.03*
C1140.1048 (2)0.65395 (18)0.51727 (9)0.0243 (3)
H1140.07760.73630.48080.029*
Atomic displacement parameters (Å2) top
U11U22U33U12U13U23
Cl120.02513 (17)0.02720 (17)0.01784 (17)0.00589 (15)0.00152 (14)0.00549 (12)
N110.0194 (5)0.0181 (5)0.0146 (5)0.0016 (5)0.0004 (4)0.0024 (5)
O120.0232 (4)0.0229 (4)0.0180 (4)0.0007 (3)0.0032 (3)0.0004 (3)
C30.0158 (6)0.0234 (7)0.0140 (7)0.0011 (5)0.0006 (5)0.0012 (5)
C20.0122 (6)0.0218 (6)0.0167 (6)0.0010 (5)0.0007 (5)0.0026 (5)
C1110.0136 (6)0.0216 (6)0.0145 (6)0.0013 (5)0.0015 (5)0.0012 (5)
C1160.0168 (6)0.0224 (6)0.0198 (7)0.0008 (5)0.0010 (5)0.0028 (5)
C40.0232 (4)0.0229 (4)0.0180 (4)0.0007 (3)0.0032 (3)0.0004 (3)
C1130.0202 (7)0.0333 (7)0.0152 (6)0.0025 (6)0.0003 (5)0.0019 (6)
C50.0211 (6)0.0230 (7)0.0241 (8)0.0020 (6)0.0011 (6)0.0025 (6)
C1120.0151 (6)0.0236 (7)0.0165 (7)0.0019 (5)0.0026 (5)0.0027 (5)
C1150.0212 (7)0.0224 (7)0.0242 (7)0.0013 (6)0.0062 (5)0.0008 (6)
C10.0212 (6)0.0221 (7)0.0175 (7)0.0018 (5)0.0007 (5)0.0032 (5)
C1140.0228 (7)0.0276 (7)0.0224 (8)0.0032 (6)0.0042 (6)0.0077 (6)
Geometric parameters (Å, º) top
Cl12—C1121.7412 (15)C4—C51.508 (2)
N11—C21.3494 (18)C113—C1121.383 (2)
N11—C1111.4049 (18)C113—C1141.387 (2)
N11—H110.8243C113—H1130.95
O12—C41.2524 (18)C5—H5A0.98
C3—C21.3787 (19)C5—H5B0.98
C3—C41.425 (2)C5—H5C0.98
C3—H30.95C115—C1141.388 (2)
C2—C11.5005 (19)C115—H1150.95
C111—C1161.3942 (19)C1—H1A0.98
C111—C1121.3994 (19)C1—H1B0.98
C116—C1151.389 (2)C1—H1C0.98
C116—H1160.95C114—H1140.95
C2—N11—C111129.12 (13)C4—C5—H5A109.5
C2—N11—H11115.4C4—C5—H5B109.5
C111—N11—H11115.4H5A—C5—H5B109.5
C2—C3—C4123.95 (13)C4—C5—H5C109.5
C2—C3—H3118H5A—C5—H5C109.5
C4—C3—H3118H5B—C5—H5C109.5
N11—C2—C3119.67 (12)C113—C112—C111121.98 (13)
N11—C2—C1120.21 (13)C113—C112—Cl12118.89 (11)
C3—C2—C1120.11 (12)C111—C112—Cl12119.13 (11)
C116—C111—C112117.74 (13)C114—C115—C116120.12 (13)
C116—C111—N11122.69 (12)C114—C115—H115119.9
C112—C111—N11119.50 (12)C116—C115—H115119.9
C115—C116—C111120.82 (13)C2—C1—H1A109.5
C115—C116—H116119.6C2—C1—H1B109.5
C111—C116—H116119.6H1A—C1—H1B109.5
O12—C4—C3123.13 (14)C2—C1—H1C109.5
O12—C4—C5118.48 (14)H1A—C1—H1C109.5
C3—C4—C5118.35 (13)H1B—C1—H1C109.5
C112—C113—C114119.11 (14)C113—C114—C115120.18 (14)
C112—C113—H113120.4C113—C114—H114119.9
C114—C113—H113120.4C115—C114—H114119.9
C111—N11—C2—C3177.99 (12)C114—C113—C112—C1110.1 (2)
C111—N11—C2—C10.9 (2)C114—C113—C112—Cl12179.63 (11)
C4—C3—C2—N111.8 (2)C116—C111—C112—C1131.8 (2)
C4—C3—C2—C1179.31 (13)N11—C111—C112—C113178.91 (12)
C2—N11—C111—C11646.2 (2)C116—C111—C112—Cl12177.84 (10)
C2—N11—C111—C112136.84 (15)N11—C111—C112—Cl120.77 (17)
C112—C111—C116—C1152.6 (2)C111—C116—C115—C1141.5 (2)
N11—C111—C116—C115179.53 (13)C112—C113—C114—C1151.1 (2)
C2—C3—C4—O124.7 (2)C116—C115—C114—C1130.3 (2)
C2—C3—C4—C5173.14 (12)
Hydrogen-bond geometry (Å, º) top
D—H···AD—HH···AD···AD—H···A
N11—H11···O120.821.952.6317 (16)139
C113—H113···O12i0.952.423.3536 (18)166
C115—H115···O12ii0.952.433.3217 (18)157
Symmetry codes: (i) x1/2, y+1/2, z+1; (ii) x, y+1, z.

Experimental details

Crystal data
Chemical formulaC11H12ClNO
Mr209.67
Crystal system, space groupOrthorhombic, P212121
Temperature (K)100
a, b, c (Å)7.3264 (3), 8.7103 (4), 16.1960 (7)
V3)1033.55 (8)
Z4
Radiation typeMo Kα
µ (mm1)0.33
Crystal size (mm)0.6 × 0.42 × 0.21
Data collection
DiffractometerBruker APEXII CCD area-detector
diffractometer
Absorption correctionMulti-scan
(SADABS; Bruker, 2004)
Tmin, Tmax0.825, 0.933
No. of measured, independent and
observed [I > 2σ(I)] reflections
17399, 2259, 2211
Rint0.032
(sin θ/λ)max1)0.639
Refinement
R[F2 > 2σ(F2)], wR(F2), S 0.025, 0.068, 1.06
No. of reflections2259
No. of parameters126
H-atom treatmentH atoms treated by a mixture of independent and constrained refinement
Δρmax, Δρmin (e Å3)0.21, 0.24
Absolute structureFlack (1983), 932 Friedel pairs
Absolute structure parameter0.01 (5)

Computer programs: APEX2 (Bruker, 2005), SAINT-Plus (Bruker, 2004), SHELXS97 (Sheldrick, 2008), SHELXL97 (Sheldrick, 2008), DIAMOND (Brandenburg & Putz, 2005), WinGX (Farrugia, 1999).

Hydrogen-bond geometry (Å, º) top
D—H···AD—HH···AD···AD—H···A
N11—H11···O120.821.952.6317 (16)139.2
C113—H113···O12i0.952.423.3536 (18)166.1
C115—H115···O12ii0.952.433.3217 (18)157.1
Symmetry codes: (i) x1/2, y+1/2, z+1; (ii) x, y+1, z.
 

Acknowledgements

Financial assistance from the University of the Free State is gratefully acknowledged. We also express our gratitude towards SASOL, the South African National Research Foundation (SA-NRF/THRIP) and the Inkaba yeAfrica initiative for financial support of this project. Part of this material is based on work supported by the SA-NRF/THRIP under grant No. GUN 2068915. Opinions, findings, conclusions or recommendations expressed in this material are those of the authors and do not necessarily reflect the views of the SA-NRF.

References

First citationBrandenburg, K. & Putz, H. (2005). DIAMOND. Crystal Impact GbR, Bonn, Germany.
First citationBrink, A., Visser, H. G., Steyl, G. & Roodt, A. (2010). Dalton Trans. 39, 5572–5578.  Web of Science CSD CrossRef CAS PubMed
First citationBruker (2004). SAINT-Plus and SADABS. Bruker AXS Inc., Madison, Wisconsin, USA.
First citationBruker (2005). APEX2. Bruker AXS Inc., Madison, Wisconsin, USA.
First citationDamoense, L. J., Purcell, W., Roodt, A. & Leipoldt, J. G. (1994). Rhodium Express, 5, 10–13.  CAS
First citationFarrugia, L. J. (1999). J. Appl. Cryst. 32, 837–838.  CrossRef CAS IUCr Journals
First citationFlack, H. D. (1983). Acta Cryst. A39, 876–881.  CrossRef CAS Web of Science IUCr Journals
First citationPyżuk, W., Krówczynsk, A. & Górecka, E. (1993). Mol. Cryst. Liq. Cryst. 237, 75–84.
First citationRoodt, A. & Steyn, G. J. J. (2000). Recent Research Developments in Inorganic Chemistry. Vol. 2, pp. 1–23. Trivandrum: Transworld Research Network.
First citationShaheen, F., Marchio, L., Badshah, A. & Khosa, M. K. (2006). Acta Cryst. E62, o873–o874.  Web of Science CSD CrossRef IUCr Journals
First citationSheldrick, G. M. (2008). Acta Cryst. A64, 112–122.  Web of Science CrossRef CAS IUCr Journals
First citationTan, H. Y., Loke, W. K., Tan, Y. T. & Nguyen, N.-T. (2008). Lab Chip, 8, 885–891.  CrossRef PubMed CAS
First citationVenter, G. J. S., Steyl, G. & Roodt, A. (2010). Acta Cryst. E66, o3011–o3012.  Web of Science CSD CrossRef IUCr Journals
First citationVenter, G. J. S., Steyl, G. & Roodt, A. (2012a). Acta Cryst. E68, m666–m667.  CSD CrossRef IUCr Journals
First citationVenter, G. J. S., Steyl, G. & Roodt, A. (2012b). Acta Cryst. E68, o2930–o2931.  CSD CrossRef IUCr Journals
First citationXia, M., Wu, B. & Xiang, G. (2008). J. Fluor. Chem. 129, 402–408.  Web of Science CSD CrossRef CAS

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
Volume 68| Part 11| November 2012| Pages o3101-o3102
Follow Acta Cryst. E
Sign up for e-alerts
Follow Acta Cryst. on Twitter
Follow us on facebook
Sign up for RSS feeds