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Acta Crystallogr Sect E Struct Rep Online. 2008 January 1; 64(Pt 1): m88–m89.
Published online 2007 December 6. doi:  10.1107/S1600536807063933
PMCID: PMC2947776

Bis(2-amino­pyridine-κN 1)bis­(benzoato-κO)cobalt(II)

Abstract

In the title compound, [Co(C7H5O2)2(C5H6N2)2], the CoII atom is hexa­coordinated by four O atoms from two benzoate anions, and two N atoms from two 2-amino­pyridine mol­ecules, resulting in a distorted octa­hedral geometry. Both benzoate anions act as bidentate ligands and both 2-amino­pyridine mol­ecules are coordinated to the metal through their pyridyl N atoms. The crystal packing is stabilized by inter­molecular N—H(...)O hydrogen bonds, C—H(...)π, and π–π stacking inter­actions involving benzoate anions and 2-amino­pyridine mol­ecules.

Related literature

For related literature, see: Benbellat et al. (2006 [triangle]); Brechin et al. (2000 [triangle]); Dirnitrou et al. (1995 [triangle]); Kozlevčar et al. (2001 [triangle]); Zhu, Shao et al. (2003 [triangle]); Zhu, Usman et al. (2003 [triangle]).

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Object name is e-64-00m88-scheme1.jpg

Experimental

Crystal data

  • [Co(C7H5O2)2(C5H6N2)2]
  • M r = 489.39
  • Monoclinic, An external file that holds a picture, illustration, etc.
Object name is e-64-00m88-efi1.jpg
  • a = 9.0230 (9) Å
  • b = 11.3787 (12) Å
  • c = 22.451 (2) Å
  • β = 96.7650 (10)°
  • V = 2288.9 (4) Å3
  • Z = 4
  • Mo Kα radiation
  • μ = 0.79 mm−1
  • T = 296 (2) K
  • 0.36 × 0.28 × 0.22 mm

Data collection

  • Bruker SMART CCD area-detector diffractometer
  • Absorption correction: multi-scan (SADABS; Sheldrick, 1996 [triangle]) T min = 0.770, T max = 0.835
  • 19674 measured reflections
  • 5288 independent reflections
  • 4198 reflections with I > 2σ(I)
  • R int = 0.027

Refinement

  • R[F 2 > 2σ(F 2)] = 0.034
  • wR(F 2) = 0.092
  • S = 1.05
  • 5288 reflections
  • 298 parameters
  • 357 restraints
  • H-atom parameters constrained
  • Δρmax = 0.32 e Å−3
  • Δρmin = −0.27 e Å−3

Data collection: SMART (Bruker, 2004 [triangle]); cell refinement: SAINT (Bruker, 2004 [triangle]); data reduction: SAINT; program(s) used to solve structure: SHELXS97 (Sheldrick, 1997a [triangle]); program(s) used to refine structure: SHELXL97 (Sheldrick, 1997a [triangle]); molecular graphics: SHELXTL (Sheldrick, 1997b [triangle]); software used to prepare material for publication: SHELXTL.

Table 1
Selected geometric parameters (Å, °)
Table 2
Hydrogen-bond geometry (Å, °)
Table 3
π–π Interactions (Å, °)

Supplementary Material

Crystal structure: contains datablocks global, I. DOI: 10.1107/S1600536807063933/kp2149sup1.cif

Structure factors: contains datablocks I. DOI: 10.1107/S1600536807063933/kp2149Isup2.hkl

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

Acknowledgments

The authors thank the National Natural Science Foundation of China (Nos. 20361002 and 30460153), 973 Plan of China (2007CB516805).

supplementary crystallographic information

Comment

In recent years the study of crystal structures and properties of cobalt complexes based on carboxyl ligand, owing to their novel geometries and magnetic behaviours, have attracted chemists (Tan et al., 2003; Zheng et al., 2004; Wang et al., 2004; Shi et al., 2004) to explore their use. The structures of the mixed ligand complexes containing benzoate as the most simple aromatic carboxyl compoud with well antibacterial activity and 2-aminopyridine reported by (Kozlevčar et al., 2001; Zhu, Usman et al., 2003; Zhu, Shao et al., 2004). Herein, we report the synthesis and crystal structure of mixed ligands cobalt(II) complex.

The stucture of the title compound (I) is isostructural with the nickel (I) complex (Zhu, Shao et al., 2003) with the CoII atom hexa-coordinated by four O atoms of two benzoato anions, and two independent pyridine N atoms from two 2-aminopyridine molecules in distorted octahedral geometry (Fig. 1). The Co—N bond lengths of 2.1030 (14) Å and 2.1054 (14) Å, the Co—O distances ranging from 2.0363 (13) to 2.4016 (15) Å, are in the normal range. The close carboxylato distances O1—C8 and O2—C8, 1.260 (2) Å and 1.250 (2) Å, O3—C1 and O4—C1, 1.241 (2) Å and 1.274 (2) Å reveal the bidentate benzoato function. The molecules are held together by intramolecular and intermolecular hydrogen bonds, C—H···π and π–π stacking interactions generating three-dimensional supramolecular network.The amide N2 and N4 donate H atoms to the carboxyl O atoms O1and O4 in intramolecular N2—H2A···O1 and N4—H4A···O4 hydrogen bonds. The N2 and N4 also donate H atoms to O2 and O3 to form intermolecular N2—H2B···O2 and N4—H4B···O3 hydrogen bonds. Intermolecular C—H···π interation is pronounced in this crystal structure involving methyl group C13 of the benzoato and the pyridyl rings N1→C24, with the distance 2.95 Å between the methyl hydrogen and the centroid of the nearest aromatic ring. In addition, π–π stacking interactions are also observed; the distance between centroids of the pyridyl ring N3→C19 and the aromatic ring C2→C7 is 3.7145 (16) Å (Table 1, Fig. 2).

Experimental

The reagents available commercially were used without further purification. Co(NO3)2.6H2O (0.5 mmol), benzoate sodium (1 mmol) and 2-aminopyridine (1 mmol) were mixed in solution containing 8 ml of ethanol and 8 ml of water. After stirring 1.5 h, the mixture was placed in 25 ml Teflon-lined reactor and heated at 383 K in an oven for 7 days. The resulting solution was filtered and the filtrate was allowed to stay at ambience temperature. Well shaped purple crystals suitable for X-rays diffraction were obtained after two weeks. Yield: 78%.

Refinement

All the H atoms were placed in geometrically idealized positions and constrained to ride on their parent atoms, with N—H, C—H distances of 0.86 Å, 0.93 Å and with Uiso(H) = 1.2Ueq(C or N).

Figures

Fig. 1.
The structure of (I) with the 30% probability displacement ellipsoids and the atom-labeling scheme.
Fig. 2.
Three-dimensional supramolecular network constructed by hydrogen bonding (dashed lines) and C—H···π, π-π interactions.

Crystal data

[Co(C7H5O2)2(C5H6N2)2]F000 = 1012
Mr = 489.39Dx = 1.420 Mg m3
Monoclinic, P21/nMo Kα radiation λ = 0.71073 Å
Hall symbol: -P 2ynCell parameters from 7256 reflections
a = 9.0230 (9) Åθ = 2.4–27.2º
b = 11.3787 (12) ŵ = 0.79 mm1
c = 22.451 (2) ÅT = 296 (2) K
β = 96.7650 (10)ºBlock, purple
V = 2288.9 (4) Å30.36 × 0.28 × 0.22 mm
Z = 4

Data collection

Bruker APEXII CCD area-detector diffractometer5288 independent reflections
Radiation source: fine-focus sealed tube4198 reflections with I > 2σ(I)
Monochromator: graphiteRint = 0.027
T = 296(2) Kθmax = 27.7º
phi and ω scansθmin = 1.8º
Absorption correction: multi-scan(SADABS; Sheldrick, 1996)h = −11→11
Tmin = 0.770, Tmax = 0.835k = −14→14
19674 measured reflectionsl = −29→25

Refinement

Refinement on F2Secondary atom site location: difference Fourier map
Least-squares matrix: fullHydrogen site location: inferred from neighbouring sites
R[F2 > 2σ(F2)] = 0.034H-atom parameters constrained
wR(F2) = 0.092  w = 1/[σ2(Fo2) + (0.0416P)2 + 0.6259P] where P = (Fo2 + 2Fc2)/3
S = 1.05(Δ/σ)max = 0.050
5288 reflectionsΔρmax = 0.32 e Å3
298 parametersΔρmin = −0.27 e Å3
357 restraintsExtinction correction: none
Primary atom site location: structure-invariant direct methods

Special details

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)

xyzUiso*/Ueq
Co10.29899 (3)0.42895 (2)0.123207 (11)0.04251 (10)
N10.37446 (18)0.31734 (14)0.05834 (7)0.0434 (4)
N20.3314 (2)0.44408 (15)−0.02241 (8)0.0520 (4)
H2A0.27730.4869−0.00190.062*
H2B0.34390.4640−0.05840.062*
N30.11106 (18)0.33308 (14)0.14242 (7)0.0429 (4)
N40.2282 (2)0.2407 (2)0.22706 (9)0.0745 (6)
H4A0.31080.27360.22080.089*
H4B0.22540.19490.25740.089*
O10.1750 (2)0.55468 (13)0.06636 (7)0.0651 (5)
O20.2427 (2)0.60479 (15)0.15868 (8)0.0698 (5)
O30.54634 (19)0.51020 (15)0.13357 (6)0.0602 (4)
O40.45109 (17)0.39318 (15)0.19532 (6)0.0566 (4)
C10.5594 (2)0.45573 (18)0.18175 (9)0.0444 (4)
C20.6981 (2)0.4610 (2)0.22510 (10)0.0504 (5)
C30.7083 (3)0.3990 (3)0.27797 (11)0.0690 (7)
H30.62840.35390.28750.083*
C40.8401 (4)0.4045 (3)0.31715 (15)0.0957 (10)
H40.84830.36370.35330.115*
C50.9565 (4)0.4697 (4)0.30237 (19)0.1039 (11)
H51.04460.47160.32840.125*
C60.9476 (3)0.5316 (4)0.2510 (2)0.1015 (11)
H61.02830.57650.24210.122*
C70.8173 (3)0.5283 (3)0.21134 (14)0.0760 (7)
H70.81020.57100.17580.091*
C80.1784 (2)0.62950 (18)0.10788 (10)0.0520 (5)
C90.1044 (2)0.74580 (18)0.09538 (10)0.0499 (5)
C100.1555 (3)0.8438 (2)0.12792 (12)0.0667 (6)
H100.23640.83730.15750.080*
C110.0872 (4)0.9512 (2)0.11675 (15)0.0842 (8)
H110.12361.01730.13810.101*
C12−0.0346 (4)0.9607 (3)0.07410 (16)0.0886 (9)
H12−0.08131.03310.06700.106*
C13−0.0872 (4)0.8644 (3)0.04219 (15)0.0880 (8)
H13−0.17060.87090.01380.106*
C14−0.0171 (3)0.7572 (2)0.05190 (12)0.0696 (7)
H14−0.05150.69230.02920.084*
C15−0.0147 (2)0.3464 (2)0.10357 (10)0.0529 (5)
H15−0.01060.39560.07070.063*
C16−0.1465 (3)0.2924 (2)0.10970 (12)0.0634 (6)
H16−0.22950.30330.08150.076*
C17−0.1537 (3)0.2207 (2)0.15906 (12)0.0643 (6)
H17−0.24260.18340.16480.077*
C18−0.0309 (3)0.2052 (2)0.19887 (11)0.0594 (6)
H18−0.03530.15780.23240.071*
C190.1036 (2)0.26105 (18)0.18948 (9)0.0479 (5)
C200.3961 (2)0.34636 (17)0.00178 (8)0.0426 (4)
C210.4848 (3)0.27532 (19)−0.03144 (10)0.0532 (5)
H210.50280.2980−0.06970.064*
C220.5438 (3)0.1739 (2)−0.00744 (11)0.0610 (6)
H220.60250.1268−0.02910.073*
C230.5157 (3)0.1407 (2)0.05002 (11)0.0614 (6)
H230.55250.07040.06690.074*
C240.4331 (3)0.21426 (19)0.08048 (10)0.0548 (5)
H240.41560.19260.11900.066*

Atomic displacement parameters (Å2)

U11U22U33U12U13U23
Co10.04193 (16)0.05067 (17)0.03496 (15)−0.00377 (11)0.00463 (10)0.00284 (11)
N10.0453 (9)0.0461 (9)0.0388 (8)−0.0058 (7)0.0051 (7)0.0010 (7)
N20.0644 (11)0.0542 (10)0.0393 (9)0.0026 (8)0.0141 (8)0.0041 (7)
N30.0430 (9)0.0459 (9)0.0404 (8)−0.0037 (7)0.0080 (7)−0.0016 (7)
N40.0630 (13)0.0910 (16)0.0676 (13)−0.0130 (11)0.0000 (10)0.0383 (12)
O10.0964 (13)0.0450 (8)0.0594 (10)−0.0035 (8)0.0324 (9)−0.0087 (7)
O20.0713 (11)0.0598 (10)0.0745 (11)0.0096 (8)−0.0071 (9)−0.0133 (9)
O30.0701 (10)0.0665 (10)0.0455 (8)−0.0001 (8)0.0132 (7)0.0081 (7)
O40.0462 (8)0.0740 (10)0.0483 (8)−0.0136 (7)0.0003 (6)0.0080 (7)
C10.0448 (11)0.0493 (10)0.0399 (10)0.0008 (8)0.0088 (8)−0.0041 (8)
C20.0403 (10)0.0578 (12)0.0537 (12)0.0024 (9)0.0082 (9)−0.0181 (10)
C30.0601 (14)0.0847 (16)0.0591 (14)0.0156 (12)−0.0058 (11)−0.0075 (12)
C40.083 (2)0.119 (2)0.0781 (18)0.0320 (18)−0.0214 (16)−0.0218 (17)
C50.0558 (17)0.136 (3)0.113 (2)0.0282 (18)−0.0207 (17)−0.062 (2)
C60.0519 (15)0.125 (2)0.128 (3)−0.0153 (16)0.0137 (17)−0.060 (2)
C70.0550 (14)0.0890 (17)0.0862 (17)−0.0142 (13)0.0174 (13)−0.0327 (15)
C80.0520 (12)0.0452 (11)0.0625 (13)−0.0078 (9)0.0225 (10)−0.0096 (10)
C90.0507 (12)0.0462 (10)0.0556 (12)−0.0041 (9)0.0179 (9)−0.0073 (9)
C100.0746 (16)0.0515 (12)0.0732 (15)−0.0025 (11)0.0052 (12)−0.0129 (11)
C110.108 (2)0.0492 (13)0.097 (2)0.0020 (14)0.0172 (18)−0.0177 (13)
C120.098 (2)0.0639 (16)0.106 (2)0.0221 (15)0.0193 (18)0.0063 (16)
C130.0807 (19)0.0802 (19)0.100 (2)0.0087 (15)−0.0046 (16)0.0101 (16)
C140.0707 (16)0.0606 (14)0.0754 (16)−0.0063 (12)−0.0003 (13)−0.0067 (12)
C150.0504 (12)0.0540 (12)0.0530 (12)−0.0063 (9)0.0013 (9)0.0007 (10)
C160.0467 (12)0.0608 (13)0.0809 (16)−0.0081 (10)−0.0001 (11)−0.0041 (12)
C170.0498 (13)0.0555 (13)0.0900 (17)−0.0121 (10)0.0191 (12)−0.0067 (12)
C180.0655 (14)0.0483 (11)0.0686 (14)−0.0083 (10)0.0257 (12)0.0039 (10)
C190.0511 (11)0.0451 (10)0.0495 (11)−0.0017 (9)0.0146 (9)−0.0001 (9)
C200.0412 (10)0.0454 (10)0.0412 (9)−0.0104 (8)0.0050 (8)−0.0040 (8)
C210.0579 (13)0.0544 (12)0.0493 (11)−0.0079 (10)0.0151 (9)−0.0079 (9)
C220.0602 (14)0.0558 (13)0.0685 (14)−0.0024 (10)0.0141 (11)−0.0156 (11)
C230.0654 (14)0.0489 (12)0.0683 (14)0.0016 (10)0.0015 (11)−0.0004 (11)
C240.0614 (13)0.0525 (12)0.0503 (12)−0.0043 (10)0.0058 (10)0.0039 (10)

Geometric parameters (Å, °)

Co1—O42.0364 (15)C6—H60.9300
Co1—N32.1033 (16)C7—H70.9300
Co1—N12.1050 (16)C8—C91.494 (3)
Co1—O12.1426 (18)C9—C101.383 (3)
Co1—O22.2340 (17)C9—C141.386 (3)
Co1—O32.4016 (17)C10—C111.378 (4)
N1—C201.348 (2)C10—H100.9300
N1—C241.357 (3)C11—C121.374 (4)
N2—C201.341 (3)C11—H110.9300
N2—H2A0.8600C12—C131.364 (5)
N2—H2B0.8600C12—H120.9300
N3—C191.345 (3)C13—C141.379 (4)
N3—C151.356 (3)C13—H130.9300
N4—C191.344 (3)C14—H140.9300
N4—H4A0.8600C15—C161.360 (3)
N4—H4B0.8600C15—H150.9300
O1—C81.260 (3)C16—C171.384 (4)
O2—C81.249 (3)C16—H160.9300
O3—C11.240 (2)C17—C181.350 (4)
O4—C11.274 (2)C17—H170.9300
C1—C21.493 (3)C18—C191.408 (3)
C2—C31.375 (3)C18—H180.9300
C2—C71.385 (3)C20—C211.411 (3)
C3—C41.395 (4)C21—C221.355 (3)
C3—H30.9300C21—H210.9300
C4—C51.359 (6)C22—C231.396 (3)
C4—H40.9300C22—H220.9300
C5—C61.345 (5)C23—C241.358 (3)
C5—H50.9300C23—H230.9300
C6—C71.389 (4)C24—H240.9300
O4—Co1—N3102.55 (6)O2—C8—O1119.5 (2)
O4—Co1—N1100.77 (7)O2—C8—C9121.34 (19)
N3—Co1—N199.40 (6)O1—C8—C9119.2 (2)
O4—Co1—O1149.63 (7)C10—C9—C14118.9 (2)
N3—Co1—O195.25 (7)C10—C9—C8120.1 (2)
N1—Co1—O1100.34 (6)C14—C9—C8121.0 (2)
O4—Co1—O293.20 (7)C11—C10—C9120.3 (3)
N3—Co1—O299.72 (7)C11—C10—H10119.8
N1—Co1—O2153.21 (7)C9—C10—H10119.8
O1—Co1—O259.31 (6)C12—C11—C10120.1 (3)
O4—Co1—O357.88 (5)C12—C11—H11120.0
N3—Co1—O3160.43 (6)C10—C11—H11120.0
N1—Co1—O385.79 (6)C13—C12—C11120.2 (3)
O1—Co1—O3102.40 (6)C13—C12—H12119.9
O2—Co1—O382.44 (6)C11—C12—H12119.9
C20—N1—C24117.60 (18)C12—C13—C14120.2 (3)
C20—N1—Co1126.75 (13)C12—C13—H13119.9
C24—N1—Co1114.33 (13)C14—C13—H13119.9
C20—N2—H2A120.0C13—C14—C9120.3 (3)
C20—N2—H2B120.0C13—C14—H14119.8
H2A—N2—H2B120.0C9—C14—H14119.8
C19—N3—C15117.26 (17)N3—C15—C16124.0 (2)
C19—N3—Co1126.38 (14)N3—C15—H15118.0
C15—N3—Co1116.35 (13)C16—C15—H15118.0
C19—N4—H4A120.0C15—C16—C17118.2 (2)
C19—N4—H4B120.0C15—C16—H16120.9
H4A—N4—H4B120.0C17—C16—H16120.9
C8—O1—Co192.57 (15)C18—C17—C16119.7 (2)
C8—O2—Co188.66 (13)C18—C17—H17120.2
C1—O3—Co183.32 (13)C16—C17—H17120.2
C1—O4—Co199.33 (12)C17—C18—C19119.8 (2)
O3—C1—O4119.41 (19)C17—C18—H18120.1
O3—C1—C2122.31 (19)C19—C18—H18120.1
O4—C1—C2118.28 (18)N4—C19—N3118.84 (18)
C3—C2—C7120.1 (2)N4—C19—C18120.1 (2)
C3—C2—C1120.5 (2)N3—C19—C18121.1 (2)
C7—C2—C1119.4 (2)N2—C20—N1118.69 (18)
C2—C3—C4119.1 (3)N2—C20—C21120.54 (18)
C2—C3—H3120.4N1—C20—C21120.77 (19)
C4—C3—H3120.4C22—C21—C20119.9 (2)
C5—C4—C3119.8 (4)C22—C21—H21120.1
C5—C4—H4120.1C20—C21—H21120.1
C3—C4—H4120.1C21—C22—C23119.5 (2)
C4—C5—C6121.7 (3)C21—C22—H22120.3
C4—C5—H5119.1C23—C22—H22120.3
C6—C5—H5119.2C24—C23—C22118.0 (2)
C5—C6—C7119.7 (3)C24—C23—H23121.0
C5—C6—H6120.1C22—C23—H23121.0
C7—C6—H6120.1C23—C24—N1124.2 (2)
C2—C7—C6119.5 (3)C23—C24—H24117.9
C2—C7—H7120.2N1—C24—H24117.9
C6—C7—H7120.2

Hydrogen-bond geometry (Å, °)

D—H···AD—HH···AD···AD—H···A
N2—H2A···O10.862.032.866 (2)163
N2—H2B···O3i0.862.072.891 (2)158
N4—H4A···O40.861.992.810 (2)160
N4—H4B···O2ii0.862.142.980 (2)167

Symmetry codes: (i) −x+1, −y+1, −z; (ii) −x+1/2, y−1/2, −z+1/2.

Table 3 C-H···π interactions (Å, °)

C—H···CgaH···CgC···CgγbC—H···Cg
C13—H13···Cg(N1→C24)iii2.953.719 (3)6.07141

Notes: Cga = centre of gravity of the six-membered ring. γb = angle defined by a line connecting centre of gravity of the six-membered ring with H atom and the normal to the six-membered ring. Symmetry code: (iii) -x, 1 - y, -z.

Table 4 π–π interactions (Å, °)

π–π contactsCg···Cgαa(βbCg···Plane
Cg(N3→C19)···Cg(C2→C7)iv3.7145 (16)6.3016.023.535
Cg(C2→C7)···Cg(N3→C19)v3.7145 (16)6.3017.873.570

Notes: αa = angle between planes of two aromatic rings. βb = angle between Cg···Cg line and normal to the plane of the first aromatic ring. Symmetry codes: (iv) -1 + x, y, z; (v) 1 + x, y, z.

Footnotes

Supplementary data and figures for this paper are available from the IUCr electronic archives (Reference: KP2149).

References

  • Benbellat, N., Gavrilenko, K.-S., Gal, Y.-L., Cador, O., Golhen, S., Guoasmia, A., Fabre, J.-M. & Ouahab, L. (2006). Inorg. Chem.45, 10440–10442. [PubMed]
  • Brechin, E.-K., Graham, A., Parkin, A., Parsons, S., Seddon, A.-M. & Winpenny, R.-E.-P. (2000). J. Chem. Soc. Dalton Trans. pp. 3242–3252.
  • Bruker (2004). SMART and SAINT. Bruker AXS Inc., Madison, Wisconsin, USA.
  • Dirnitrou, K., Sun, J.-S., Folting, K. & Christou, G. (1995). Inorg. Chem.34, 4160–4166.
  • Kozlevčar, B., Lah, N., Žlindra, D., Leban, I. & šegedin, P. (2001). Acta Chim. Slov.48, 363–374.
  • Sheldrick, G. M. (1996). SADABS. University of Göttingen, Germany.
  • Sheldrick, G. M. (1997a). SHELXS97 and SHELXL97. University of Göttingen, Germany.
  • Sheldrick, G. M. (1997b). SHELXTL. Bruker AXS Inc., Madison, Wisconsin, USA.
  • Zhu, H.-L., Shao, S.-C., Ma, J.-L., Qiu, X.-Y., Sun, L. & Yang, S. (2003). Acta Cryst. E59, m843–m844.
  • Zhu, H.-L., Usman, A., Fun, H.-K. & Wang, X.-J. (2003). Acta Cryst. C59, m218–m220. [PubMed]

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