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Acta Crystallogr Sect E Struct Rep Online. 2010 August 1; 66(Pt 8): m987.
Published online 2010 July 21. doi:  10.1107/S1600536810023561
PMCID: PMC3007493

catena-Poly[[(1,10-phenanthroline)lead(II)]bis­(μ-5-chloro-2-hy­droxy­benzoato)]

Abstract

In the title polymer, [Pb(C7H4ClO3)2(C12H8N2)]n, the Pb(II) ion displays a distorted pseudo-octa­hedral coordination geometry. The metal center is coordinated by six O atoms from four 5-chloro­salicylate ligands and two N atoms from a chelating phenanthroline ligand. The polymeric structure is built up from bridging carboxyl­ate O atoms, forming chains along [100]. The crystal structure is stabilized by π–π inter­actions between the 1,10-phenanthroline and 5-chloro­salicylate ligands, the shortest centroid–centroid separation between neighbouring aromatic rings being 3.652 (1) Å.

Related literature

For related non-polymeric complexes including 5-chloro­salicylate ligands, see: Wen & Ying (2007 [triangle]); Wen et al. (2008 [triangle]).

An external file that holds a picture, illustration, etc.
Object name is e-66-0m987-scheme1.jpg

Experimental

Crystal data

  • [Pb(C7H4ClO3)2(C12H8N2)]
  • M r = 730.51
  • Triclinic, An external file that holds a picture, illustration, etc.
Object name is e-66-0m987-efi1.jpg
  • a = 8.9100 (1) Å
  • b = 11.2959 (1) Å
  • c = 13.5816 (1) Å
  • α = 75.508 (1)°
  • β = 86.302 (1)°
  • γ = 68.342 (1)°
  • V = 1229.43 (2) Å3
  • Z = 2
  • Mo Kα radiation
  • μ = 7.13 mm−1
  • T = 296 K
  • 0.28 × 0.25 × 0.24 mm

Data collection

  • Bruker APEXII CCD diffractometer
  • Absorption correction: multi-scan (SADABS; Bruker, 2001 [triangle]) T min = 0.156, T max = 0.181
  • 21579 measured reflections
  • 5987 independent reflections
  • 5339 reflections with I > 2σ(I)
  • R int = 0.029

Refinement

  • R[F 2 > 2σ(F 2)] = 0.025
  • wR(F 2) = 0.064
  • S = 1.05
  • 5987 reflections
  • 334 parameters
  • H-atom parameters constrained
  • Δρmax = 1.18 e Å−3
  • Δρmin = −0.59 e Å−3

Data collection: APEX2 (Bruker, 2001 [triangle]); cell refinement: SAINT (Bruker, 2001 [triangle]); data reduction: SAINT; program(s) used to solve structure: SHELXS97 (Sheldrick, 2008 [triangle]); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008 [triangle]); molecular graphics: SHELXTL (Sheldrick, 2008 [triangle]); software used to prepare material for publication: SHELXTL.

Supplementary Material

Crystal structure: contains datablocks I, global. DOI: 10.1107/S1600536810023561/bh2289sup1.cif

Structure factors: contains datablocks I. DOI: 10.1107/S1600536810023561/bh2289Isup2.hkl

Additional supplementary materials: crystallographic information; 3D view; checkCIF report

Acknowledgments

The authors are grateful for financial support from the Foundation of Zhejiang Educational Committee (No. Y200908533), the Open Fund for Zhejiang Provincial Key of Biological and Chemical Utilization of Forest Resources (No. 200907) and the Fund of Zhejiang Forestry University (No. 235100998).

supplementary crystallographic information

Comment

The Pb(II) ion in the asymmetric unit is pseudo-octahedrally coordinated (Fig. 1), with coordination to six O atoms from four 5-chlorosalicylate ligands, and two N atoms from a chelating phenanthroline (phen) ligand. Two related complexes, [Zn(C7H4ClO3)2(C12H8N2)(H2O)] and [Cd(C7H4ClO3)2(C12H8N2)2], were reported (Wen & Ying, 2007; Wen et al., 2008, respectively), both with 5-chlorosalicylate ions acting as monodentate ligands, while in the title polymer, 5-chlorosalicylate ions are bidentate ligands.

The Pb—O distances (Table 1) vary from 2.458 (3) to 2.887 (3) Å, which are close to those found in Pb2(PMIDA).1.5H2O [from 2.331 (9) to 2.876 (9) Å; H4PMIDA is N-(phosphonomethyl)iminodiacetic acid]. Each pair of adjacent Pb(II) ions is bridged by the O1 atom of 5-chlorosalicylate, which forms a SBU (secondary building units, Fig. 2) including two Pb polyhedron, six 5-chlorosalicylate and two phen. The Pb···Pb distance in the dimeric unit is 4.3587 (2) Å. The SBU is bridged by O5 atom of 5-chlorosalicylate, to give rise to a zigzag chain (Fig. 3). The excellent coordinating ability and large conjugated systems of phen and 5-chlorosalicylate allow to form π···π interactions. The chains are extended into the framework through π..π interactions between the ligands from adjacent chains.

Experimental

The pH value of a mixture of Pb(NO3)2 (0.5 mmol), phen (0.5 mmol) and 5-chlorosalicylic acid (0.5 mmol) in 8 ml of distilled water and 16 ml of ethanol was adjusted between 5 and 6 by addition of sodium hydroxide. The resultant solution was refluxed for 6 h. After cooling, yellow crystals were formed over 2 days, at room temperature.

Refinement

H atoms were placed geometrically with bond lengths fixed to 0.82 (OH) and 0.93 Å (CH). Isotropic displacement parameters for H atoms were calculated as Uiso(H) = 1.2Ueq(carrier C) and Uiso(H) = 1.5Ueq(carrier O).

Figures

Fig. 1.
The Pb coordination geometry in the title compound, with thermal ellipsoids at the 50% probability level. Symmetry codes: A 1 - x, -y, -z; B: -x, -y, -z.
Fig. 2.
A section of the structure of the title complex showing SBU with shared corner O atoms.
Fig. 3.
The chain of the title polymer, viewed down the a axis.

Crystal data

[Pb(C7H4ClO3)2(C12H8N2)]Z = 2
Mr = 730.51F(000) = 700
Triclinic, P1Dx = 1.973 Mg m3
Hall symbol: -P 1Mo Kα radiation, λ = 0.71073 Å
a = 8.9100 (1) ÅCell parameters from 5987 reflections
b = 11.2959 (1) Åθ = 2.8–26.9°
c = 13.5816 (1) ŵ = 7.13 mm1
α = 75.508 (1)°T = 296 K
β = 86.302 (1)°Block, yellow
γ = 68.342 (1)°0.28 × 0.25 × 0.24 mm
V = 1229.43 (2) Å3

Data collection

Bruker APEXII CCD diffractometer5987 independent reflections
Radiation source: fine-focus sealed tube5339 reflections with I > 2σ(I)
graphiteRint = 0.029
[var phi] and ω scansθmax = 28.2°, θmin = 2.0°
Absorption correction: multi-scan (SADABS; Bruker, 2001)h = −11→11
Tmin = 0.156, Tmax = 0.181k = −14→14
21579 measured reflectionsl = −18→17

Refinement

Refinement on F2Primary atom site location: structure-invariant direct methods
Least-squares matrix: fullSecondary atom site location: difference Fourier map
R[F2 > 2σ(F2)] = 0.025Hydrogen site location: inferred from neighbouring sites
wR(F2) = 0.064H-atom parameters constrained
S = 1.05w = 1/[σ2(Fo2) + (0.0349P)2 + 0.472P] where P = (Fo2 + 2Fc2)/3
5987 reflections(Δ/σ)max = 0.001
334 parametersΔρmax = 1.18 e Å3
0 restraintsΔρmin = −0.59 e Å3
0 constraints

Fractional atomic coordinates and isotropic or equivalent isotropic displacement parameters (Å2)

xyzUiso*/Ueq
Pb10.258486 (14)−0.038882 (12)−0.001073 (10)0.03675 (5)
Cl11.04796 (14)−0.31797 (16)0.36720 (10)0.0779 (4)
Cl2−0.2949 (2)−0.0117 (2)0.47404 (14)0.1106 (6)
O50.0025 (3)0.0001 (3)0.1216 (2)0.0495 (6)
O10.5607 (4)−0.1240 (3)0.0939 (2)0.0548 (7)
O20.3533 (3)−0.1567 (3)0.1750 (2)0.0569 (7)
O40.1160 (4)0.1481 (3)0.1053 (2)0.0604 (8)
N10.2350 (4)−0.2615 (3)0.0256 (2)0.0423 (7)
N20.4307 (4)−0.1896 (3)−0.1218 (3)0.0449 (7)
C120.2979 (4)−0.3371 (3)−0.0407 (3)0.0394 (8)
O30.3774 (4)−0.2835 (5)0.3602 (3)0.0882 (13)
H3B0.3326−0.24360.30430.132*
C110.3981 (4)−0.2980 (4)−0.1197 (3)0.0409 (8)
C130.5001 (4)−0.1665 (3)0.1727 (3)0.0417 (8)
C140.5973 (4)−0.2334 (4)0.2701 (3)0.0421 (8)
C150.5322 (5)−0.2888 (6)0.3575 (3)0.0609 (12)
C70.4610 (5)−0.3747 (4)−0.1912 (3)0.0509 (10)
C80.5574 (6)−0.3329 (5)−0.2661 (4)0.0615 (12)
H8A0.6005−0.3804−0.31480.074*
O60.0401 (4)0.3062 (3)0.2185 (3)0.0704 (9)
H6B0.08090.27560.17020.106*
C21−0.0455 (4)0.1217 (4)0.2486 (3)0.0419 (8)
C40.2689 (5)−0.4538 (4)−0.0344 (4)0.0496 (9)
C10.1447 (5)−0.2992 (4)0.0995 (3)0.0506 (9)
H1A0.1000−0.24650.14460.061*
C22−0.0349 (5)0.2293 (5)0.2767 (3)0.0512 (10)
C190.7579 (5)−0.2452 (4)0.2740 (3)0.0449 (8)
H19A0.8040−0.21070.21600.054*
C200.0289 (4)0.0873 (4)0.1522 (3)0.0447 (9)
C90.5890 (6)−0.2234 (5)−0.2688 (4)0.0634 (12)
H9A0.6523−0.1946−0.31910.076*
C20.1143 (6)−0.4148 (5)0.1118 (4)0.0590 (11)
H2A0.0533−0.43960.16550.071*
C100.5239 (5)−0.1554 (5)−0.1941 (3)0.0551 (10)
H10A0.5475−0.0814−0.19520.066*
C26−0.1257 (5)0.0475 (4)0.3101 (3)0.0510 (9)
H26A−0.1347−0.02360.29160.061*
C30.1744 (6)−0.4899 (4)0.0450 (4)0.0616 (12)
H3A0.1529−0.56600.05170.074*
C50.3351 (6)−0.5275 (5)−0.1086 (4)0.0664 (13)
H5A0.3147−0.6033−0.10540.080*
C60.4259 (6)−0.4894 (5)−0.1825 (4)0.0660 (13)
H6A0.4673−0.5396−0.22970.079*
C25−0.1914 (6)0.0793 (5)0.3981 (3)0.0638 (12)
C24−0.1821 (6)0.1881 (6)0.4256 (4)0.0740 (15)
H24A−0.22850.20990.48510.089*
C23−0.1051 (6)0.2610 (6)0.3650 (4)0.0688 (13)
H23A−0.09930.33350.38300.083*
C180.8483 (5)−0.3069 (5)0.3622 (3)0.0616 (12)
C170.7827 (7)−0.3620 (7)0.4485 (4)0.0867 (19)
H17A0.8447−0.40350.50850.104*
C160.6277 (7)−0.3553 (7)0.4453 (4)0.090 (2)
H16A0.5853−0.39560.50250.108*

Atomic displacement parameters (Å2)

U11U22U33U12U13U23
Pb10.03379 (8)0.04199 (8)0.03692 (8)−0.01778 (5)0.00344 (5)−0.00846 (5)
Cl10.0494 (6)0.1113 (10)0.0641 (8)−0.0373 (7)−0.0139 (5)0.0104 (7)
Cl20.1064 (12)0.1390 (15)0.0809 (10)−0.0634 (11)0.0396 (9)0.0020 (10)
O50.0489 (15)0.0541 (15)0.0449 (16)−0.0154 (13)−0.0012 (12)−0.0156 (13)
O10.0612 (18)0.0596 (17)0.0402 (16)−0.0272 (15)−0.0072 (13)0.0037 (13)
O20.0420 (15)0.0743 (19)0.0543 (18)−0.0233 (14)−0.0065 (13)−0.0106 (15)
O40.0583 (18)0.072 (2)0.0588 (19)−0.0311 (16)0.0224 (15)−0.0228 (16)
N10.0386 (16)0.0421 (15)0.0465 (18)−0.0169 (13)0.0001 (13)−0.0076 (13)
N20.0396 (16)0.0503 (18)0.0479 (19)−0.0189 (14)0.0051 (14)−0.0144 (15)
C120.0337 (17)0.0355 (17)0.044 (2)−0.0068 (14)−0.0094 (15)−0.0072 (14)
O30.054 (2)0.168 (4)0.055 (2)−0.063 (2)0.0100 (16)−0.016 (2)
C110.0334 (17)0.0426 (18)0.043 (2)−0.0090 (15)−0.0082 (15)−0.0089 (15)
C130.0431 (19)0.0386 (18)0.046 (2)−0.0132 (15)−0.0020 (16)−0.0157 (16)
C140.0409 (19)0.051 (2)0.038 (2)−0.0194 (16)0.0004 (15)−0.0123 (16)
C150.052 (2)0.097 (4)0.042 (2)−0.037 (2)0.0066 (19)−0.017 (2)
C70.047 (2)0.049 (2)0.048 (2)−0.0041 (17)−0.0109 (18)−0.0144 (18)
C80.059 (3)0.073 (3)0.045 (2)−0.010 (2)0.003 (2)−0.023 (2)
O60.068 (2)0.075 (2)0.085 (3)−0.0421 (18)0.0217 (18)−0.0284 (19)
C210.0324 (17)0.054 (2)0.0364 (19)−0.0137 (16)−0.0002 (14)−0.0095 (16)
C40.050 (2)0.0374 (19)0.058 (2)−0.0137 (17)−0.0157 (19)−0.0045 (17)
C10.050 (2)0.051 (2)0.050 (2)−0.0226 (18)0.0022 (18)−0.0045 (18)
C220.038 (2)0.065 (3)0.052 (2)−0.0196 (19)0.0005 (17)−0.016 (2)
C190.0416 (19)0.052 (2)0.039 (2)−0.0193 (17)0.0012 (16)−0.0035 (16)
C200.0338 (18)0.055 (2)0.040 (2)−0.0095 (16)−0.0021 (15)−0.0103 (17)
C90.053 (3)0.079 (3)0.055 (3)−0.020 (2)0.010 (2)−0.017 (2)
C20.054 (2)0.058 (3)0.061 (3)−0.029 (2)0.000 (2)0.005 (2)
C100.050 (2)0.064 (3)0.056 (3)−0.026 (2)0.014 (2)−0.018 (2)
C260.044 (2)0.061 (2)0.046 (2)−0.0218 (19)0.0014 (17)−0.0048 (18)
C30.061 (3)0.046 (2)0.078 (3)−0.027 (2)−0.011 (2)−0.003 (2)
C50.072 (3)0.045 (2)0.085 (4)−0.019 (2)−0.014 (3)−0.021 (2)
C60.073 (3)0.054 (2)0.069 (3)−0.010 (2)−0.007 (3)−0.029 (2)
C250.052 (2)0.088 (3)0.043 (2)−0.028 (2)0.0101 (19)0.000 (2)
C240.061 (3)0.111 (4)0.047 (3)−0.022 (3)0.012 (2)−0.030 (3)
C230.065 (3)0.087 (3)0.063 (3)−0.028 (3)0.011 (2)−0.036 (3)
C180.049 (2)0.090 (3)0.044 (2)−0.033 (2)−0.0051 (19)−0.001 (2)
C170.068 (3)0.146 (6)0.042 (3)−0.053 (4)−0.011 (2)0.010 (3)
C160.078 (4)0.157 (6)0.040 (3)−0.067 (4)0.001 (2)0.006 (3)

Geometric parameters (Å, °)

Pb1—O22.458 (3)C8—H8A0.9300
Pb1—O52.703 (3)O6—C221.358 (6)
Pb1—O42.734 (3)O6—H6B0.8200
Pb1—O5i2.768 (3)C21—C261.388 (6)
Pb1—O12.785 (3)C21—C221.399 (6)
Pb1—O1ii2.887 (3)C21—C201.502 (5)
Pb1—N12.534 (3)C4—C31.398 (7)
Pb1—N22.662 (3)C4—C51.426 (7)
Cl1—C181.742 (4)C1—C21.397 (6)
Cl2—C251.737 (5)C1—H1A0.9300
O5—C201.259 (5)C22—C231.382 (6)
O5—Pb1i2.768 (3)C19—C181.364 (6)
O1—C131.235 (5)C19—H19A0.9300
O1—Pb1ii2.887 (3)C9—C101.393 (7)
O2—C131.270 (5)C9—H9A0.9300
O4—C201.261 (5)C2—C31.348 (7)
N1—C11.331 (5)C2—H2A0.9300
N1—C121.350 (5)C10—H10A0.9300
N2—C101.321 (5)C26—C251.366 (6)
N2—C111.353 (5)C26—H26A0.9300
C12—C41.416 (5)C3—H3A0.9300
C12—C111.439 (5)C5—C61.336 (8)
O3—C151.357 (5)C5—H5A0.9300
O3—H3B0.8200C6—H6A0.9300
C11—C71.415 (5)C25—C241.402 (8)
C13—C141.495 (5)C24—C231.354 (8)
C14—C191.390 (5)C24—H24A0.9300
C14—C151.395 (6)C23—H23A0.9300
C15—C161.386 (7)C18—C171.385 (7)
C7—C81.394 (7)C17—C161.358 (7)
C7—C61.417 (7)C17—H17A0.9300
C8—C91.358 (7)C16—H16A0.9300
O2—Pb1—N174.00 (10)O2—C13—C14116.7 (4)
O2—Pb1—N2107.51 (10)O1—C13—Pb168.5 (2)
N1—Pb1—N263.52 (10)O2—C13—Pb153.5 (2)
O2—Pb1—O570.89 (9)C14—C13—Pb1170.2 (3)
N1—Pb1—O581.85 (9)C19—C14—C15118.5 (4)
N2—Pb1—O5143.50 (9)C19—C14—C13120.0 (3)
O2—Pb1—O476.94 (10)C15—C14—C13121.5 (3)
N1—Pb1—O4128.10 (10)O3—C15—C16117.5 (4)
N2—Pb1—O4168.25 (9)O3—C15—C14122.5 (4)
O5—Pb1—O448.05 (9)C16—C15—C14120.0 (4)
O2—Pb1—O5i135.16 (9)C8—C7—C11117.1 (4)
N1—Pb1—O5i73.83 (9)C8—C7—C6123.7 (4)
N2—Pb1—O5i84.71 (9)C11—C7—C6119.2 (4)
O5—Pb1—O5i74.36 (9)C9—C8—C7120.6 (4)
O4—Pb1—O5i99.85 (9)C9—C8—H8A119.7
O2—Pb1—O148.91 (9)C7—C8—H8A119.7
N1—Pb1—O197.78 (9)C22—O6—H6B109.5
N2—Pb1—O181.42 (10)C26—C21—C22119.5 (4)
O5—Pb1—O1116.23 (9)C26—C21—C20120.4 (4)
O4—Pb1—O194.20 (10)C22—C21—C20120.1 (4)
O5i—Pb1—O1165.95 (9)C3—C4—C12117.3 (4)
O2—Pb1—O1ii111.66 (9)C3—C4—C5123.5 (4)
N1—Pb1—O1ii145.69 (10)C12—C4—C5119.2 (4)
N2—Pb1—O1ii83.09 (9)N1—C1—C2122.6 (4)
O5—Pb1—O1ii132.42 (9)N1—C1—H1A118.7
O4—Pb1—O1ii85.17 (9)C2—C1—H1A118.7
O5i—Pb1—O1ii112.58 (8)O6—C22—C23118.4 (4)
O1—Pb1—O1ii68.01 (9)O6—C22—C21121.9 (4)
O2—Pb1—C1324.55 (10)C23—C22—C21119.7 (4)
N1—Pb1—C1385.87 (10)C18—C19—C14120.6 (4)
N2—Pb1—C1394.97 (10)C18—C19—H19A119.7
O5—Pb1—C1393.59 (10)C14—C19—H19A119.7
O4—Pb1—C1384.95 (10)O5—C20—O4122.8 (4)
O5i—Pb1—C13157.51 (10)O5—C20—C21119.4 (4)
O1—Pb1—C1324.36 (9)O4—C20—C21117.8 (4)
O1ii—Pb1—C1389.63 (10)O5—C20—Pb162.0 (2)
O2—Pb1—C2068.44 (10)O4—C20—Pb163.4 (2)
N1—Pb1—C20103.98 (11)C21—C20—Pb1163.5 (2)
N2—Pb1—C20167.39 (11)C8—C9—C10118.2 (5)
O5—Pb1—C2024.29 (10)C8—C9—H9A120.9
O4—Pb1—C2024.36 (10)C10—C9—H9A120.9
O5i—Pb1—C2090.21 (9)C3—C2—C1119.2 (4)
O1—Pb1—C20102.90 (9)C3—C2—H2A120.4
O1ii—Pb1—C20109.53 (11)C1—C2—H2A120.4
C13—Pb1—C2085.33 (10)N2—C10—C9124.0 (5)
O2—Pb1—Pb1i104.32 (7)N2—C10—H10A118.0
N1—Pb1—Pb1i74.65 (7)C9—C10—H10A118.0
N2—Pb1—Pb1i116.10 (7)C25—C26—C21119.7 (4)
O5—Pb1—Pb1i37.70 (6)C25—C26—H26A120.1
O4—Pb1—Pb1i72.18 (7)C21—C26—H26A120.1
O5i—Pb1—Pb1i36.66 (6)C2—C3—C4120.3 (4)
O1—Pb1—Pb1i152.88 (6)C2—C3—H3A119.8
O1ii—Pb1—Pb1i131.46 (6)C4—C3—H3A119.8
C13—Pb1—Pb1i128.72 (8)C6—C5—C4121.2 (4)
C20—Pb1—Pb1i55.75 (7)C6—C5—H5A119.4
C20—O5—Pb193.7 (2)C4—C5—H5A119.4
C20—O5—Pb1i126.0 (2)C5—C6—C7121.9 (4)
Pb1—O5—Pb1i105.64 (9)C5—C6—H6A119.0
C13—O1—Pb187.2 (2)C7—C6—H6A119.0
C13—O1—Pb1ii145.9 (3)C26—C25—C24120.7 (4)
Pb1—O1—Pb1ii111.99 (9)C26—C25—Cl2119.8 (4)
C13—O2—Pb1101.9 (3)C24—C25—Cl2119.5 (4)
C20—O4—Pb192.2 (2)C23—C24—C25119.5 (4)
C1—N1—C12118.6 (3)C23—C24—H24A120.3
C1—N1—Pb1119.9 (3)C25—C24—H24A120.3
C12—N1—Pb1121.1 (2)C24—C23—C22120.9 (5)
C10—N2—C11117.9 (4)C24—C23—H23A119.6
C10—N2—Pb1124.7 (3)C22—C23—H23A119.6
C11—N2—Pb1116.5 (2)C19—C18—C17120.4 (4)
N1—C12—C4121.9 (4)C19—C18—Cl1120.3 (3)
N1—C12—C11118.9 (3)C17—C18—Cl1119.3 (4)
C4—C12—C11119.2 (4)C16—C17—C18119.9 (5)
C15—O3—H3B109.5C16—C17—H17A120.1
N2—C11—C7122.2 (4)C18—C17—H17A120.1
N2—C11—C12118.5 (3)C17—C16—C15120.5 (5)
C7—C11—C12119.3 (4)C17—C16—H16A119.8
O1—C13—O2122.0 (4)C15—C16—H16A119.8
O1—C13—C14121.3 (3)

Symmetry codes: (i) −x, −y, −z; (ii) −x+1, −y, −z.

Footnotes

Supplementary data and figures for this paper are available from the IUCr electronic archives (Reference: BH2289).

References

  • Bruker (2001). APEX2, SAINT and SADABS Bruker AXS Inc., Madison, Wisconsin, USA.
  • Sheldrick, G. M. (2008). Acta Cryst. A64, 112–122. [PubMed]
  • Wen, D., Xie, J. & Jiang, X. (2008). Acta Cryst. E64, m851–m852. [PMC free article] [PubMed]
  • Wen, D. & Ying, S. (2007). Acta Cryst. E63, m2407–m2408.

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