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

Journal logoCRYSTALLOGRAPHIC
COMMUNICATIONS
ISSN: 2056-9890
Volume 66| Part 1| January 2010| Page m78
doi:10.1107/S1600536809053665

Bis{μ-1-[(2-oxidophen­yl)imino­meth­yl]-2-naphtholato}bis­­[pyridine­copper(II)]

Kai Liu,a Guihua Liu,a Zhiqiang Caoa and Meiju Niua*

aCollege of Chemistry and Chemical Engineering, Liaocheng University, Shandong 252059, People's Republic of China
*Correspondence e-mail: niumeiju@163.com

(Received 27 November 2009; accepted 14 December 2009; online 19 December 2009)

The dinuclear title complex, [Cu2(C17H11NO2)2(C5H5N)2], consists of centrosymmetric dimers in which the CuII atom displays an elongated square-pyramidal coordination geometry. The conformation of the dimer is stabilized by inter­molecular C—H⋯O hydrogen bonds and by π–π aromatic stacking inter­actions involving the pyridine and benzene rings with centroid–centroid separations of 3.624 (3) Å.

Related literature

For the properties and applications of Schiff bases, see: Garnovskii et al. (1993[Garnovskii, A. D., Nivorozhkin, A. L. & Minkin, V. I. (1993). Coord. Chem. Rev. 126, 1-69.]). For related structures, see: Zhang et al. (2003[Zhang, X.-L., Ren, C.-X., Chen, X.-M. & Ng, S. W. (2003). Acta Cryst. E59, m1176-m1177.]); Elmali et al. (1993[Elmali, A., Elerman, Y., Svoboda, I. & Fuess, H. (1993). Acta Cryst. C49, 965-967.]).

[Scheme 1]

Experimental

Crystal data

  • [Cu2(C17H11NO2)2(C5H5N)2]

  • Mr = 807.82

  • Monoclinic, P 21 /c

  • a = 9.4389 (8) Å

  • b = 15.8573 (17) Å

  • c = 12.0895 (15) Å

  • β = 105.7590 (10)°

  • V = 1741.5 (3) Å3

  • Z = 2

  • Mo Kα radiation

  • μ = 1.27 mm−1

  • T = 298 K

  • 0.50 × 0.26 × 0.16 mm
Data collection

  • Siemens SMART CCD area-detector diffractometer

  • Absorption correction: multi-scan (SADABS; Sheldrick, 1996[Sheldrick, G. M. (1996). SADABS. University of Göttingen, Germany.]) Tmin = 0.568, Tmax = 0.822

  • 8621 measured reflections

  • 3066 independent reflections

  • 2184 reflections with I > 2σ(I)

  • Rint = 0.040
Refinement

  • R[F2 > 2σ(F2)] = 0.038

  • wR(F2) = 0.092

  • S = 1.01

  • 3066 reflections

  • 244 parameters

  • H-atom parameters constrained

  • Δρmax = 0.45 e Å−3

  • Δρmin = −0.32 e Å−3

Table 1
Hydrogen-bond geometry (Å, °)

D—H⋯A D—H H⋯A D⋯A D—H⋯A
C18—H18⋯O1 0.93 2.31 2.872 (4) 119
C22—H22⋯O2 0.93 2.31 2.885 (4) 120

Data collection: SMART (Siemens, 1996[Siemens (1996). SMART and SAINT. Siemens Analytical X-ray Instruments Inc., Madison, Wisconsin, USA.]); cell refinement: SAINT (Siemens, 1996[Siemens (1996). SMART and SAINT. Siemens Analytical X-ray Instruments 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.]); software used to prepare material for publication: SHELXTL.

Supporting information

Crystal structure: contains datablocks I, global. DOI: 10.1107/S1600536809053665/rz2402sup1.cif

Structure factors: contains datablock I. DOI: 10.1107/S1600536809053665/rz2402Isup2.hkl

checkCIF report


Comment top

Schiff bases have played an important role in coordination chemistry of transition metals, mainly due to their stability, ease of preparation, structural variability and variety of applications (Garnovskii et al., 1993). Copper(II) complexes with tetradentate or tridentate N-alkylidene or N-arylidene-alkanato Schiff-base ligands are of considerable interest due to their structural and magnetic properties, in addition to being potential models for a number of important biological systems. As a continuation of our studied in this domain, we have synthesized the title complex and present its crystal structure here.

The molecular structure of the title compound is shown in Fig. 1. The compound consists of centrosymmetrical dimers where two [CuLPy] [L = 1-[(2-oxidophenyl)iminomethyl]-naphthalen-2-olato] units are linked by two bridging O2 atoms. Each copper(II) metal exhibits an elongated square pyramidal coordination geometry, with the basal plane provided by the N, O donor atoms of the tridentate L ligand and the N atom of a the pyridine molecule, and the apical position occupied by the centrosymmetrically related phenolic O2 atom (Cu1—O2i = 2.5854 (19) Å; symmetry code: (i) -x, 2-y, -z). The sum of the bond angles within the basal plane is 360.16 (10)°. The Cu—O distances of 1.900 (2)Å and 1.935 (2)Å are very close to the corresponding values found in a related structure (Zhang et al., 2003). The two copper(II) centres are 3.256 (2) Å apart and the distance between the two bridging O2 atoms is 3.208 (4) Å. The Cu—O(2)—Cui angle in the four-membered Cu2O2 ring is 90.99 (3)° (Ayhan & Yalon, 1993). The conformation of the dimer is stabilized by interligand C—H···O hydrogen bonds (Table 1) and by π–π aromatic stacking interactions occurring between centrosimmetrically related pyridine and benzene rings, with centroid-to-centroid separations of 3.624 (3) Å. The crystal packing (Fig. 2) is enforced only by van der Waals interactions.

Related literature top

For the properties and applications of Schiff bases, see: Garnovskii et al. (1993). For related structures, see: Zhang et al. (2003); Ayhan et al. (1993).

Experimental top

The Schiff base C17H13NO2 was synthesized by condensing equimolar quantities of 2-hydroxynaphthalenaldehyde and 2-aminophenol in ethanol. Copper dichloride dihydrate (2 mmol, 341.0 mg) and the Schiff base (1 mmol, 263.3 mg) were dissolved in pyridine (22 ml). The reaction was carried out under nitrogen atmosphere. The dark brown solution was stirred for four hour and then filtered. Evaporation of the solvent yielded dark green crystals of the title compound suitable for X-ray analysis. Analysis found: C 65.47, H 4.00, N 6.92%; calculated for C44H32N4O4Cu2: C 65.42, H 3.99, N 6.94%.

Refinement top

All H atoms were placed geometrically and treated as riding on their parent atoms, with C—H = 0.93 Å and Uiso(H) = 1.2 Ueq(C).

Computing details top

Data collection: SMART (Siemens, 1996); cell refinement: SAINT (Siemens, 1996); data reduction: SAINT (Siemens, 1996); program(s) used to solve structure: SHELXS97 (Sheldrick, 2008); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008); molecular graphics: SHELXTL (Sheldrick, 2008); software used to prepare material for publication: SHELXTL (Sheldrick, 2008).

Figures top
[Figure 1] Fig. 1. The molecular structure of the title complex with displacement ellipsoids drawn at the 30% probability level. Unlabelled atoms are related to labelled atoms by the symmetry operator (-x, 2-y, -z).
[Figure 2] Fig. 2. Crystal packing of the title compound viewed approximately along the a axis. Hydrogen atoms are omitted for clarity.
Bis{µ-1-[(2-oxidophenyl)iminomethyl]-2-naphtholato}bis[pyridinecopper(II)] top
Crystal data top
[Cu2(C17H11NO2)2(C5H5N)2]F(000) = 828
Mr = 807.82Dx = 1.541 Mg m−3
Monoclinic, P21/cMo Kα radiation, λ = 0.71073 Å
Hall symbol: -P 2ybcCell parameters from 2404 reflections
a = 9.4389 (8) Åθ = 2.6–24.4°
b = 15.8573 (17) ŵ = 1.27 mm−1
c = 12.0895 (15) ÅT = 298 K
β = 105.759 (1)°Block, dark green
V = 1741.5 (3) Å30.50 × 0.26 × 0.16 mm
Z = 2
Data collection top
Siemens SMART CCD area-detector
diffractometer		3066 independent reflections
Radiation source: fine-focus sealed tube2184 reflections with I > 2σ(I)
Graphite monochromatorRint = 0.040
phi and ω scansθmax = 25.0°, θmin = 2.2°
Absorption correction: multi-scan
(SADABS; Sheldrick, 1996)		h = −11→11
Tmin = 0.568, Tmax = 0.822k = −18→18
8621 measured reflectionsl = −12→14
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)] = 0.038Hydrogen site location: inferred from neighbouring sites
wR(F2) = 0.092H-atom parameters constrained
S = 1.01 w = 1/[σ2(Fo2) + (0.030P)2 + 1.6033P]
where P = (Fo2 + 2Fc2)/3
3066 reflections(Δ/σ)max = 0.001
244 parametersΔρmax = 0.45 e Å−3
0 restraintsΔρmin = −0.32 e Å−3
Crystal data top
[Cu2(C17H11NO2)2(C5H5N)2]V = 1741.5 (3) Å3
Mr = 807.82Z = 2
Monoclinic, P21/cMo Kα radiation
a = 9.4389 (8) ŵ = 1.27 mm−1
b = 15.8573 (17) ÅT = 298 K
c = 12.0895 (15) Å0.50 × 0.26 × 0.16 mm
β = 105.759 (1)°
Data collection top
Siemens SMART CCD area-detector
diffractometer		3066 independent reflections
Absorption correction: multi-scan
(SADABS; Sheldrick, 1996)		2184 reflections with I > 2σ(I)
Tmin = 0.568, Tmax = 0.822Rint = 0.040
8621 measured reflections
Refinement top
R[F2 > 2σ(F2)] = 0.0380 restraints
wR(F2) = 0.092H-atom parameters constrained
S = 1.01Δρmax = 0.45 e Å−3
3066 reflectionsΔρmin = −0.32 e Å−3
244 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
O20.0610 (2)1.05392 (13)0.11510 (18)0.0401 (6)
Cu10.15664 (4)1.03970 (2)−0.00642 (3)0.03617 (15)
N10.2782 (3)0.95821 (16)0.0972 (2)0.0312 (6)
N20.0524 (3)1.14158 (16)−0.0918 (2)0.0374 (7)
O10.2546 (3)1.01949 (14)−0.12192 (18)0.0422 (6)
C10.3687 (4)0.9057 (2)0.0708 (3)0.0346 (8)
H10.41850.86910.12840.041*
C20.3996 (3)0.8984 (2)−0.0381 (3)0.0335 (8)
C30.3440 (4)0.9580 (2)−0.1268 (3)0.0355 (8)
C40.3917 (4)0.9521 (2)−0.2291 (3)0.0406 (8)
H40.35410.9899−0.28860.049*
C50.4894 (4)0.8936 (2)−0.2422 (3)0.0438 (9)
H50.51980.8934−0.30920.053*
C60.5471 (4)0.8323 (2)−0.1564 (3)0.0376 (8)
C70.4973 (4)0.8324 (2)−0.0555 (3)0.0352 (8)
C80.5483 (4)0.7659 (2)0.0226 (3)0.0465 (9)
H80.51470.76230.08800.056*
C90.6456 (4)0.7063 (2)0.0059 (3)0.0510 (10)
H90.67570.66310.05910.061*
C100.6995 (4)0.7100 (2)−0.0902 (3)0.0496 (10)
H100.76840.6708−0.10010.060*
C110.6500 (4)0.7715 (2)−0.1693 (3)0.0461 (9)
H110.68520.7736−0.23400.055*
C120.1362 (4)1.01565 (19)0.2115 (3)0.0352 (8)
C130.2544 (3)0.96253 (19)0.2079 (3)0.0326 (7)
C140.3338 (4)0.9210 (2)0.3062 (3)0.0437 (9)
H140.41220.88630.30360.052*
C150.2961 (4)0.9315 (2)0.4081 (3)0.0518 (10)
H150.34970.90400.47420.062*
C160.1796 (5)0.9824 (2)0.4118 (3)0.0529 (10)
H160.15450.98880.48060.063*
C170.0994 (4)1.0238 (2)0.3150 (3)0.0470 (9)
H170.02021.05760.31870.056*
C180.0667 (4)1.1630 (2)−0.1946 (3)0.0536 (10)
H180.13211.1328−0.22460.064*
C19−0.0109 (5)1.2277 (3)−0.2581 (4)0.0704 (13)
H190.00181.2406−0.32980.085*
C20−0.1066 (5)1.2730 (2)−0.2158 (4)0.0648 (12)
H20−0.16091.3168−0.25820.078*
C21−0.1215 (5)1.2530 (2)−0.1098 (4)0.0556 (11)
H21−0.18511.2834−0.07800.067*
C22−0.0401 (4)1.1868 (2)−0.0505 (3)0.0444 (9)
H22−0.05071.17330.02170.053*
Atomic displacement parameters (Å2) top
U11U22U33U12U13U23
O20.0406 (14)0.0454 (14)0.0341 (13)0.0068 (11)0.0096 (11)0.0073 (11)
Cu10.0346 (3)0.0391 (2)0.0333 (2)0.0013 (2)0.00662 (18)0.00654 (19)
N10.0290 (15)0.0361 (15)0.0272 (14)−0.0016 (13)0.0056 (12)0.0024 (12)
N20.0372 (18)0.0337 (15)0.0365 (17)−0.0038 (13)0.0021 (13)0.0033 (13)
O10.0413 (15)0.0513 (15)0.0346 (13)0.0052 (12)0.0116 (11)0.0102 (11)
C10.030 (2)0.0391 (19)0.0315 (19)−0.0021 (16)0.0029 (15)0.0056 (15)
C20.031 (2)0.0392 (19)0.0285 (18)−0.0064 (15)0.0060 (15)0.0012 (15)
C30.0327 (19)0.0406 (19)0.0330 (18)−0.0091 (17)0.0086 (15)0.0012 (16)
C40.040 (2)0.051 (2)0.0283 (18)−0.0080 (18)0.0050 (15)0.0053 (16)
C50.044 (2)0.057 (2)0.033 (2)−0.0107 (19)0.0149 (17)−0.0078 (17)
C60.034 (2)0.045 (2)0.0330 (19)−0.0064 (16)0.0081 (16)−0.0067 (16)
C70.0299 (19)0.0406 (19)0.0331 (19)−0.0073 (16)0.0051 (15)−0.0060 (15)
C80.052 (2)0.051 (2)0.038 (2)0.0075 (19)0.0148 (18)0.0039 (17)
C90.051 (3)0.050 (2)0.050 (2)0.011 (2)0.012 (2)0.0022 (18)
C100.045 (2)0.054 (2)0.050 (2)0.0042 (19)0.0133 (19)−0.012 (2)
C110.042 (2)0.062 (2)0.037 (2)−0.0035 (19)0.0154 (18)−0.0086 (19)
C120.038 (2)0.0347 (19)0.0300 (19)−0.0036 (15)0.0036 (16)0.0000 (14)
C130.0311 (18)0.0366 (18)0.0281 (17)−0.0053 (16)0.0046 (14)−0.0007 (15)
C140.040 (2)0.054 (2)0.035 (2)0.0080 (18)0.0055 (17)0.0047 (17)
C150.057 (3)0.065 (3)0.030 (2)0.008 (2)0.0063 (18)0.0080 (18)
C160.067 (3)0.063 (3)0.031 (2)0.008 (2)0.0158 (19)−0.0008 (18)
C170.053 (2)0.047 (2)0.043 (2)0.0082 (18)0.0175 (19)−0.0016 (17)
C180.050 (3)0.056 (2)0.058 (3)0.010 (2)0.020 (2)0.022 (2)
C190.070 (3)0.075 (3)0.070 (3)0.020 (3)0.026 (3)0.041 (3)
C200.067 (3)0.047 (2)0.072 (3)0.007 (2)0.005 (2)0.021 (2)
C210.056 (3)0.042 (2)0.064 (3)0.0099 (19)0.008 (2)−0.004 (2)
C220.054 (3)0.037 (2)0.039 (2)−0.0018 (18)0.0067 (18)−0.0044 (16)
Geometric parameters (Å, º) top
O2—C121.334 (4)C9—C101.390 (5)
O2—Cu11.935 (2)C9—H90.9300
Cu1—O11.899 (2)C10—C111.357 (5)
Cu1—N11.943 (3)C10—H100.9300
Cu1—N22.023 (3)C11—H110.9300
N1—C11.293 (4)C12—C171.393 (4)
N1—C131.418 (4)C12—C131.408 (4)
N2—C221.328 (4)C13—C141.387 (4)
N2—C181.330 (4)C14—C151.381 (5)
O1—C31.301 (4)C14—H140.9300
C1—C21.429 (4)C15—C161.375 (5)
C1—H10.9300C15—H150.9300
C2—C31.420 (4)C16—C171.376 (5)
C2—C71.448 (4)C16—H160.9300
C3—C41.429 (4)C17—H170.9300
C4—C51.348 (5)C18—C191.368 (5)
C4—H40.9300C18—H180.9300
C5—C61.417 (5)C19—C201.358 (6)
C5—H50.9300C19—H190.9300
C6—C111.407 (5)C20—C211.364 (5)
C6—C71.421 (4)C20—H200.9300
C7—C81.410 (4)C21—C221.380 (5)
C8—C91.370 (5)C21—H210.9300
C8—H80.9300C22—H220.9300
C12—O2—Cu1111.3 (2)C10—C9—H9119.8
O1—Cu1—O2176.63 (9)C11—C10—C9119.0 (3)
O1—Cu1—N192.39 (10)C11—C10—H10120.5
O2—Cu1—N184.46 (10)C9—C10—H10120.5
O1—Cu1—N291.49 (11)C10—C11—C6122.1 (3)
O2—Cu1—N291.83 (10)C10—C11—H11119.0
N1—Cu1—N2168.64 (10)C6—C11—H11119.0
C1—N1—C13123.2 (3)O2—C12—C17122.6 (3)
C1—N1—Cu1125.7 (2)O2—C12—C13118.9 (3)
C13—N1—Cu1111.1 (2)C17—C12—C13118.4 (3)
C22—N2—C18117.2 (3)C14—C13—C12120.4 (3)
C22—N2—Cu1121.2 (2)C14—C13—N1126.8 (3)
C18—N2—Cu1121.5 (2)C12—C13—N1112.8 (3)
C3—O1—Cu1127.7 (2)C15—C14—C13119.8 (3)
N1—C1—C2126.4 (3)C15—C14—H14120.1
N1—C1—H1116.8C13—C14—H14120.1
C2—C1—H1116.8C16—C15—C14120.1 (3)
C3—C2—C1121.1 (3)C16—C15—H15120.0
C3—C2—C7119.4 (3)C14—C15—H15120.0
C1—C2—C7119.4 (3)C15—C16—C17120.9 (3)
O1—C3—C2125.2 (3)C15—C16—H16119.6
O1—C3—C4116.7 (3)C17—C16—H16119.6
C2—C3—C4118.1 (3)C16—C17—C12120.4 (3)
C5—C4—C3122.3 (3)C16—C17—H17119.8
C5—C4—H4118.9C12—C17—H17119.8
C3—C4—H4118.9N2—C18—C19122.8 (4)
C4—C5—C6121.7 (3)N2—C18—H18118.6
C4—C5—H5119.2C19—C18—H18118.6
C6—C5—H5119.2C20—C19—C18119.7 (4)
C11—C6—C5121.9 (3)C20—C19—H19120.2
C11—C6—C7119.6 (3)C18—C19—H19120.2
C5—C6—C7118.5 (3)C19—C20—C21118.7 (4)
C8—C7—C6116.3 (3)C19—C20—H20120.7
C8—C7—C2123.9 (3)C21—C20—H20120.7
C6—C7—C2119.8 (3)C20—C21—C22118.7 (4)
C9—C8—C7122.5 (3)C20—C21—H21120.7
C9—C8—H8118.8C22—C21—H21120.7
C7—C8—H8118.8N2—C22—C21123.1 (3)
C8—C9—C10120.5 (4)N2—C22—H22118.5
C8—C9—H9119.8C21—C22—H22118.5
Hydrogen-bond geometry (Å, º) top
D—H···AD—HH···AD···AD—H···A
C18—H18···O10.932.312.872 (4)119
C22—H22···O20.932.312.885 (4)120

Experimental details

Crystal data
Chemical formula[Cu2(C17H11NO2)2(C5H5N)2]
Mr807.82
Crystal system, space groupMonoclinic, P21/c
Temperature (K)298
a, b, c (Å)9.4389 (8), 15.8573 (17), 12.0895 (15)
β (°) 105.759 (1)
V (Å3)1741.5 (3)
Z2
Radiation typeMo Kα
µ (mm−1)1.27
Crystal size (mm)0.50 × 0.26 × 0.16
Data collection
DiffractometerSiemens SMART CCD area-detector
diffractometer
Absorption correctionMulti-scan
(SADABS; Sheldrick, 1996)
Tmin, Tmax0.568, 0.822
No. of measured, independent and
observed [I > 2σ(I)] reflections		8621, 3066, 2184
Rint0.040
(sin θ/λ)max (Å−1)0.595
Refinement
R[F2 > 2σ(F2)], wR(F2), S 0.038, 0.092, 1.01
No. of reflections3066
No. of parameters244
H-atom treatmentH-atom parameters constrained
Δρmax, Δρmin (e Å−3)0.45, −0.32

Computer programs: SMART (Siemens, 1996), SAINT (Siemens, 1996), SHELXS97 (Sheldrick, 2008), SHELXL97 (Sheldrick, 2008), SHELXTL (Sheldrick, 2008).

Hydrogen-bond geometry (Å, º) top
D—H···AD—HH···AD···AD—H···A
C18—H18···O10.932.312.872 (4)119
C22—H22···O20.932.312.885 (4)120
 

Acknowledgements

We acknowledge the financial support of the National Natural Science Foundation of China (20671048).

References

First citationElmali, A., Elerman, Y., Svoboda, I. & Fuess, H. (1993). Acta Cryst. C49, 965–967.  CSD CrossRef CAS Web of Science IUCr Journals Google Scholar
 First citationGarnovskii, A. D., Nivorozhkin, A. L. & Minkin, V. I. (1993). Coord. Chem. Rev. 126, 1–69.  CrossRef CAS Web of Science Google Scholar
 First citationSheldrick, G. M. (1996). 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
 First citationSiemens (1996). SMART and SAINT. Siemens Analytical X-ray Instruments Inc., Madison, Wisconsin, USA.  Google Scholar
 First citationZhang, X.-L., Ren, C.-X., Chen, X.-M. & Ng, S. W. (2003). Acta Cryst. E59, m1176–m1177.  Web of Science CSD CrossRef 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.

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ISSN: 2056-9890
Volume 66| Part 1| January 2010| Page m78
doi:10.1107/S1600536809053665
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