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

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ISSN: 2056-9890
Volume 68| Part 4| April 2012| Pages m486-m487

Tetra­aqua­bis­­[4-(1H-imidazol-1-yl-κN3)benzoato]cobalt(II)

aCollege of Chemistry and Chemical Engineering, Donghua University, Shanghai 200051, People's Republic of China, bCollege of Food Science and Technology, Guangdong Ocean University, Zhanjiang 524088, People's Republic of China, and cCollege of Science, Guangdong Ocean University, Zhanjiang 524088, People's Republic of China
*Correspondence e-mail: liujianshe@dhu.edu.cn

(Received 23 February 2012; accepted 9 March 2012; online 28 March 2012)

In the title compound, [Co(C10H7N2O2)2(H2O)4], the CoII atom lies on an inversion centre and displays a slightly distorted octa­hedral geometry. The coordination sphere is defined by two mutually trans N atoms from two 4-(imidazol-1-yl)benzoate ligands and the O atoms from four water mol­ecules. The crystal structure is stabilized by O—H⋯O hydrogen bonds.

Related literature

For our previous work on imidazole derivatives as ligands, see: Li, Song et al. (2011[Li, S. J., Song, W. D., Miao, D. L., Hu, S. W., Ji, L. L. & Ma, D. Y. (2011). Z. Anorg. Allg. Chem. 637, 1246-1252.]); Li, Ma et al. (2011[Li, S.-J., Ma, X.-T., Song, W.-D., Li, X.-F. & Liu, J.-H. (2011). Acta Cryst. E67, m295-m296.]); Fan et al. (2010[Fan, R.-Z., Li, S.-J., Song, W.-D., Miao, D.-L. & Hu, S.-W. (2010). Acta Cryst. E66, m897-m898.]); Li et al. (2010[Li, S.-J., Miao, D.-L., Song, W.-D., Li, S.-H. & Yan, J.-B. (2010). Acta Cryst. E66, m1096-m1097.]).

[Scheme 1]

Experimental

Crystal data
  • [Co(C10H7N2O2)2(H2O)4]

  • Mr = 505.35

  • Monoclinic, P 21 /c

  • a = 12.1976 (15) Å

  • b = 10.6555 (13) Å

  • c = 7.9602 (10) Å

  • β = 96.816 (2)°

  • V = 1027.3 (2) Å3

  • Z = 2

  • Mo Kα radiation

  • μ = 0.89 mm−1

  • T = 296 K

  • 0.22 × 0.19 × 0.15 mm

Data collection
  • Bruker APEXII area-detector diffractometer

  • Absorption correction: multi-scan (SADABS; Sheldrick, 1996[Sheldrick, G. M. (1996). SADABS. University of Göttingen, Germany.]) Tmin = 0.616, Tmax = 0.744

  • 7094 measured reflections

  • 1850 independent reflections

  • 1720 reflections with I > 2σ(I)

  • Rint = 0.048

Refinement
  • R[F2 > 2σ(F2)] = 0.032

  • wR(F2) = 0.092

  • S = 1.07

  • 1850 reflections

  • 151 parameters

  • 6 restraints

  • H-atom parameters constrained

  • Δρmax = 0.31 e Å−3

  • Δρmin = −0.36 e Å−3

Table 1
Selected bond lengths (Å)

Co1—O1W 2.1286 (13)
Co1—O2W 2.0644 (13)
Co1—N2 2.1238 (15)

Table 2
Hydrogen-bond geometry (Å, °)

D—H⋯A D—H H⋯A DA D—H⋯A
O2W—H3W⋯O2i 0.84 1.88 2.6745 (17) 157
O2W—H4W⋯O2ii 0.85 1.86 2.6964 (18) 170
O1W—H2W⋯O2i 0.83 2.03 2.8287 (19) 163
O1W—H1W⋯O1iii 0.83 1.87 2.7014 (18) 177
Symmetry codes: (i) -x+1, -y+1, -z+2; (ii) [-x+1, y-{\script{1\over 2}}, -z+{\script{3\over 2}}]; (iii) x+1, y, z+1.

Data collection: APEX2 (Bruker, 2004[Bruker (2004). APEX2 and SAINT. Bruker AXS Inc., Madison, Wisconsin, USA.]); cell refinement: SAINT (Bruker, 2004[Bruker (2004). APEX2 and SAINT. Bruker AXS 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: XP in SHELXTL (Sheldrick, 2008[Sheldrick, G. M. (2008). Acta Cryst. A64, 112-122.]); software used to prepare material for publication: SHELXL97.

Supporting information


Comment top

During the past decade, considerable efforts have been devoted to design and construct new metal-organic frameworks due to their intriguing structural diversity and potential application in many areas. In recent years, our research group has shown great interest in the design and synthesis of interesting metal-organic complexes with imidazole derivatives such as 2-propyl-imidazole-4,5-dicarboxylic acid (Fan et al., 2010; Li et al., 2010) and 2-ethyl-1H-imidazole-4,5-dicarboxylic acid (Li, Song et al., 2011; Li, Ma et al., 2011). In this paper, we report the synthesis and structure of a new CoII complex, [Co(C10H7N2O2)2(H2O)4].

As illustrated in Fig. 1, the title compound, consists of a CoII cation, two deprotonated 4-(imidazol-1-yl)benzoic acid ligands and four coordinated water molecules. Each six coordinate CoII ion, lies on an inversion center with the N atoms of the 4-(imidazol-1-yl)benzoic acid ligands mutually trans and the four water molecules in an equatorial plane. The Co–N distance is 2.1238 (15) Å and Co–O distances are 2.0643 (13) Å and 2.1287 (14) Å, respectively. It is interesting to note that in this molecule, the 4-(imidazol-1-yl)benzoic acid ligands coordinate to Co(II) via a nitrogen atom of the imidazole residue unlike several other complexes of dicarboxylic acid derivatives we have reported previously, which coordinate to metal atoms via the carboxylate group (Fan et al., 2010; Li et al., 2010; Li, Song et al., 2011; Li, Ma et al., 2011). In the crystal structure, molecules form a three-dimensional network through an extensive series of intermolecular O—H···O hydrogen bonds.

Related literature top

For our previous work on imidazole derivatives as ligands, see: Li, Song et al. (2011); Li, Ma et al. (2011); Fan et al. (2010); Li et al. (2010).

Experimental top

A mixture of Co(NO3)2.6H2O (0.5 mmol, 0.15 g) and 4-(imidazol-1-yl)benzoic acid (1 mmol, 0.19 g) in 12 ml of H2O was sealed in an autoclave equipped with a Teflon liner (20 ml) and then heated to 433 K for 4 days. After gradual cooling to room temperature, red crystals were obtained and collected by filtration with a yield of 31% based on Co.

Refinement top

Carbon and nitrogen bound H atoms were placed at calculated positions and were treated as riding on the parent C or N atoms with C—H = 0.93 Å, N—H = 0.86 Å, and with Uiso(H) = 1.2 Ueq(C, N). H atoms of the water molecules were located in a difference Fourier map and refined as riding with an O—H distance restraint of 0.84 (1) Å and with Uiso(H) = 1.5 Ueq. The H···H distances within the water molecules were also restrained to 1.39 (1) Å.

Structure description top

During the past decade, considerable efforts have been devoted to design and construct new metal-organic frameworks due to their intriguing structural diversity and potential application in many areas. In recent years, our research group has shown great interest in the design and synthesis of interesting metal-organic complexes with imidazole derivatives such as 2-propyl-imidazole-4,5-dicarboxylic acid (Fan et al., 2010; Li et al., 2010) and 2-ethyl-1H-imidazole-4,5-dicarboxylic acid (Li, Song et al., 2011; Li, Ma et al., 2011). In this paper, we report the synthesis and structure of a new CoII complex, [Co(C10H7N2O2)2(H2O)4].

As illustrated in Fig. 1, the title compound, consists of a CoII cation, two deprotonated 4-(imidazol-1-yl)benzoic acid ligands and four coordinated water molecules. Each six coordinate CoII ion, lies on an inversion center with the N atoms of the 4-(imidazol-1-yl)benzoic acid ligands mutually trans and the four water molecules in an equatorial plane. The Co–N distance is 2.1238 (15) Å and Co–O distances are 2.0643 (13) Å and 2.1287 (14) Å, respectively. It is interesting to note that in this molecule, the 4-(imidazol-1-yl)benzoic acid ligands coordinate to Co(II) via a nitrogen atom of the imidazole residue unlike several other complexes of dicarboxylic acid derivatives we have reported previously, which coordinate to metal atoms via the carboxylate group (Fan et al., 2010; Li et al., 2010; Li, Song et al., 2011; Li, Ma et al., 2011). In the crystal structure, molecules form a three-dimensional network through an extensive series of intermolecular O—H···O hydrogen bonds.

For our previous work on imidazole derivatives as ligands, see: Li, Song et al. (2011); Li, Ma et al. (2011); Fan et al. (2010); Li et al. (2010).

Computing details top

Data collection: APEX2 (Bruker, 2004); cell refinement: SAINT (Bruker, 2004); data reduction: SAINT (Bruker, 2004); program(s) used to solve structure: SHELXS97 (Sheldrick, 2008); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008); molecular graphics: XP in SHELXTL (Sheldrick, 2008); software used to prepare material for publication: SHELXL97 (Sheldrick, 2008).

Figures top
[Figure 1] Fig. 1. The structure of the title compound, showing the atomic numbering scheme. Non-H atoms are shown with 30% probability displacement ellipsoids (H atoms are omitted for clarity). [Symmetry code: i = 2 - x, 1 - y, 2 - z.]
Tetraaquabis[4-(1H-imidazol-1-yl-κN3)benzoato]cobalt(II) top
Crystal data top
[Co(C10H7N2O2)2(H2O)4]F(000) = 522
Mr = 505.35Dx = 1.634 Mg m3
Monoclinic, P21/cMo Kα radiation, λ = 0.71073 Å
Hall symbol: -P 2ybcCell parameters from 5837 reflections
a = 12.1976 (15) Åθ = 2.8–27.9°
b = 10.6555 (13) ŵ = 0.89 mm1
c = 7.9602 (10) ÅT = 296 K
β = 96.816 (2)°Block, red
V = 1027.3 (2) Å30.22 × 0.19 × 0.15 mm
Z = 2
Data collection top
Bruker APEXII area-detector
diffractometer
1850 independent reflections
Radiation source: fine-focus sealed tube1720 reflections with I > 2σ(I)
Graphite monochromatorRint = 0.048
φ and ω scanθmax = 25.2°, θmin = 1.7°
Absorption correction: multi-scan
(SADABS; Sheldrick, 1996)
h = 1414
Tmin = 0.616, Tmax = 0.744k = 1212
7094 measured reflectionsl = 99
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)] = 0.032Hydrogen site location: inferred from neighbouring sites
wR(F2) = 0.092H-atom parameters constrained
S = 1.07 w = 1/[σ2(Fo2) + (0.0491P)2 + 0.4159P]
where P = (Fo2 + 2Fc2)/3
1850 reflections(Δ/σ)max < 0.001
151 parametersΔρmax = 0.31 e Å3
6 restraintsΔρmin = 0.36 e Å3
Crystal data top
[Co(C10H7N2O2)2(H2O)4]V = 1027.3 (2) Å3
Mr = 505.35Z = 2
Monoclinic, P21/cMo Kα radiation
a = 12.1976 (15) ŵ = 0.89 mm1
b = 10.6555 (13) ÅT = 296 K
c = 7.9602 (10) Å0.22 × 0.19 × 0.15 mm
β = 96.816 (2)°
Data collection top
Bruker APEXII area-detector
diffractometer
1850 independent reflections
Absorption correction: multi-scan
(SADABS; Sheldrick, 1996)
1720 reflections with I > 2σ(I)
Tmin = 0.616, Tmax = 0.744Rint = 0.048
7094 measured reflections
Refinement top
R[F2 > 2σ(F2)] = 0.0326 restraints
wR(F2) = 0.092H-atom parameters constrained
S = 1.07Δρmax = 0.31 e Å3
1850 reflectionsΔρmin = 0.36 e Å3
151 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
C10.55457 (14)0.61139 (17)0.8770 (2)0.0122 (4)
C20.52906 (16)0.51963 (18)0.7536 (2)0.0159 (4)
H20.58270.46300.72820.019*
C30.42300 (17)0.51351 (17)0.6690 (3)0.0158 (4)
H30.40660.45300.58550.019*
C40.34080 (14)0.59535 (17)0.7058 (2)0.0122 (4)
C50.36592 (15)0.68373 (17)0.8335 (2)0.0146 (4)
H50.31110.73740.86250.018*
C60.47249 (14)0.69250 (17)0.9181 (2)0.0140 (4)
H60.48870.75261.00220.017*
C70.70472 (16)0.70111 (19)1.0893 (2)0.0208 (4)
H70.66440.75991.14270.025*
C80.81424 (16)0.67658 (18)1.1233 (2)0.0194 (4)
H80.86230.71681.20560.023*
C90.75273 (15)0.55233 (18)0.9212 (2)0.0156 (4)
H90.74900.49110.83740.019*
C100.22864 (14)0.59036 (17)0.6021 (2)0.0132 (4)
Co11.00000.50001.00000.01069 (15)
N10.66473 (12)0.62083 (14)0.95870 (17)0.0124 (3)
N20.84354 (12)0.58317 (15)1.01756 (18)0.0150 (3)
O10.22401 (10)0.54154 (14)0.45864 (16)0.0187 (3)
O20.14737 (10)0.63844 (12)0.66430 (15)0.0158 (3)
O1W1.02638 (11)0.52252 (13)1.26744 (17)0.0167 (3)
H1W1.08660.52651.32810.025*
H2W0.97940.48001.30890.025*
O2W0.93348 (12)0.32615 (13)1.04136 (16)0.0231 (3)
H4W0.91500.26860.97010.035*
H3W0.89410.32411.12110.035*
Atomic displacement parameters (Å2) top
U11U22U33U12U13U23
C10.0122 (8)0.0135 (9)0.0108 (8)0.0007 (7)0.0013 (6)0.0028 (7)
C20.0131 (10)0.0182 (9)0.0161 (10)0.0045 (7)0.0010 (8)0.0030 (7)
C30.0163 (10)0.0177 (10)0.0130 (9)0.0001 (7)0.0007 (8)0.0029 (7)
C40.0123 (9)0.0147 (9)0.0100 (8)0.0002 (7)0.0023 (7)0.0032 (7)
C50.0142 (9)0.0144 (9)0.0157 (9)0.0027 (7)0.0035 (7)0.0003 (7)
C60.0153 (9)0.0137 (9)0.0132 (9)0.0011 (7)0.0025 (7)0.0014 (6)
C70.0175 (10)0.0228 (10)0.0208 (10)0.0045 (8)0.0025 (8)0.0110 (8)
C80.0170 (10)0.0222 (10)0.0179 (9)0.0011 (8)0.0034 (7)0.0074 (8)
C90.0118 (9)0.0203 (10)0.0145 (9)0.0017 (7)0.0011 (7)0.0035 (7)
C100.0145 (9)0.0132 (9)0.0119 (9)0.0004 (7)0.0020 (7)0.0039 (7)
Co10.0086 (2)0.0135 (2)0.0097 (2)0.00079 (11)0.00011 (15)0.00126 (11)
N10.0111 (7)0.0148 (7)0.0111 (7)0.0016 (6)0.0010 (6)0.0004 (6)
N20.0123 (8)0.0189 (8)0.0135 (7)0.0005 (6)0.0001 (6)0.0004 (6)
O10.0144 (7)0.0289 (8)0.0124 (7)0.0013 (6)0.0005 (5)0.0042 (6)
O20.0112 (6)0.0231 (7)0.0132 (6)0.0029 (5)0.0023 (5)0.0021 (5)
O1W0.0128 (7)0.0254 (7)0.0118 (6)0.0028 (5)0.0006 (5)0.0006 (5)
O2W0.0325 (8)0.0198 (7)0.0197 (7)0.0101 (6)0.0145 (6)0.0077 (5)
Geometric parameters (Å, º) top
C1—C61.391 (3)C8—H80.9300
C1—C21.395 (3)C9—N21.312 (2)
C1—N11.425 (2)C9—N11.360 (2)
C2—C31.387 (3)C9—H90.9300
C2—H20.9300C10—O11.250 (2)
C3—C41.386 (3)C10—O21.268 (2)
C3—H30.9300Co1—O1Wi2.1286 (13)
C4—C51.393 (3)Co1—O1W2.1286 (13)
C4—C101.513 (2)Co1—O2W2.0644 (13)
C5—C61.395 (2)Co1—O2Wi2.0644 (13)
C5—H50.9300Co1—N22.1238 (15)
C6—H60.9300Co1—N2i2.1238 (15)
C7—C81.357 (3)O1W—H1W0.8307
C7—N11.389 (2)O1W—H2W0.8296
C7—H70.9300O2W—H4W0.8479
C8—N21.378 (2)O2W—H3W0.8402
C6—C1—C2119.67 (16)O2—C10—C4118.10 (15)
C6—C1—N1120.96 (15)O2W—Co1—O2Wi180.0
C2—C1—N1119.37 (16)O2W—Co1—N289.47 (6)
C3—C2—C1119.48 (17)O2Wi—Co1—N290.53 (6)
C3—C2—H2120.3O2W—Co1—N2i90.53 (6)
C1—C2—H2120.3O2Wi—Co1—N2i89.47 (6)
C4—C3—C2121.60 (17)N2—Co1—N2i180.0
C4—C3—H3119.2O2W—Co1—O1Wi92.45 (5)
C2—C3—H3119.2O2Wi—Co1—O1Wi87.55 (5)
C3—C4—C5118.53 (16)N2—Co1—O1Wi94.73 (5)
C3—C4—C10119.50 (16)N2i—Co1—O1Wi85.27 (5)
C5—C4—C10121.91 (16)O2W—Co1—O1W87.55 (5)
C4—C5—C6120.65 (16)O2Wi—Co1—O1W92.45 (5)
C4—C5—H5119.7N2—Co1—O1W85.27 (5)
C6—C5—H5119.7N2i—Co1—O1W94.73 (5)
C1—C6—C5120.01 (16)O1Wi—Co1—O1W180.0
C1—C6—H6120.0C9—N1—C7106.18 (15)
C5—C6—H6120.0C9—N1—C1125.99 (15)
C8—C7—N1106.30 (16)C7—N1—C1127.83 (15)
C8—C7—H7126.9C9—N2—C8106.02 (15)
N1—C7—H7126.9C9—N2—Co1124.04 (13)
C7—C8—N2109.76 (16)C8—N2—Co1129.94 (12)
C7—C8—H8125.1Co1—O1W—H1W127.2
N2—C8—H8125.1Co1—O1W—H2W107.9
N2—C9—N1111.74 (16)H1W—O1W—H2W113.7
N2—C9—H9124.1Co1—O2W—H4W128.4
N1—C9—H9124.1Co1—O2W—H3W114.5
O1—C10—O2124.93 (16)H4W—O2W—H3W110.8
O1—C10—C4116.95 (15)
Symmetry code: (i) x+2, y+1, z+2.
Hydrogen-bond geometry (Å, º) top
D—H···AD—HH···AD···AD—H···A
O2W—H3W···O2ii0.841.882.6745 (17)157
O2W—H4W···O2iii0.851.862.6964 (18)170
O1W—H2W···O2ii0.832.032.8287 (19)163
O1W—H1W···O1iv0.831.872.7014 (18)177
Symmetry codes: (ii) x+1, y+1, z+2; (iii) x+1, y1/2, z+3/2; (iv) x+1, y, z+1.

Experimental details

Crystal data
Chemical formula[Co(C10H7N2O2)2(H2O)4]
Mr505.35
Crystal system, space groupMonoclinic, P21/c
Temperature (K)296
a, b, c (Å)12.1976 (15), 10.6555 (13), 7.9602 (10)
β (°) 96.816 (2)
V3)1027.3 (2)
Z2
Radiation typeMo Kα
µ (mm1)0.89
Crystal size (mm)0.22 × 0.19 × 0.15
Data collection
DiffractometerBruker APEXII area-detector
Absorption correctionMulti-scan
(SADABS; Sheldrick, 1996)
Tmin, Tmax0.616, 0.744
No. of measured, independent and
observed [I > 2σ(I)] reflections
7094, 1850, 1720
Rint0.048
(sin θ/λ)max1)0.599
Refinement
R[F2 > 2σ(F2)], wR(F2), S 0.032, 0.092, 1.07
No. of reflections1850
No. of parameters151
No. of restraints6
H-atom treatmentH-atom parameters constrained
Δρmax, Δρmin (e Å3)0.31, 0.36

Computer programs: APEX2 (Bruker, 2004), SAINT (Bruker, 2004), SHELXS97 (Sheldrick, 2008), SHELXL97 (Sheldrick, 2008), XP in SHELXTL (Sheldrick, 2008).

Selected bond lengths (Å) top
Co1—O1W2.1286 (13)Co1—N22.1238 (15)
Co1—O2W2.0644 (13)
Hydrogen-bond geometry (Å, º) top
D—H···AD—HH···AD···AD—H···A
O2W—H3W···O2i0.841.882.6745 (17)156.8
O2W—H4W···O2ii0.851.862.6964 (18)169.6
O1W—H2W···O2i0.832.032.8287 (19)162.6
O1W—H1W···O1iii0.831.872.7014 (18)177.4
Symmetry codes: (i) x+1, y+1, z+2; (ii) x+1, y1/2, z+3/2; (iii) x+1, y, z+1.
 

Acknowledgements

The work was supported by the National Marine Public Welfare Projects (grant No. 2000905021), the Guangdong Chinese Academy of Science comprehensive strategic cooperation project (grant No. 2009B091300121), the Guangdong Province Key Project in the Field of Social Development [grant No. A2009011–007(c)], the Science and Technology Department of Guangdong Province Project (grant No. 00087061110314018) and the Guangdong Natural Science Foundation (No. 925240880002).

References

First citationBruker (2004). APEX2 and SAINT. Bruker AXS Inc., Madison, Wisconsin, USA.  Google Scholar
First citationFan, R.-Z., Li, S.-J., Song, W.-D., Miao, D.-L. & Hu, S.-W. (2010). Acta Cryst. E66, m897–m898.  Web of Science CSD CrossRef CAS IUCr Journals Google Scholar
First citationLi, S.-J., Ma, X.-T., Song, W.-D., Li, X.-F. & Liu, J.-H. (2011). Acta Cryst. E67, m295–m296.  Web of Science CSD CrossRef IUCr Journals Google Scholar
First citationLi, S.-J., Miao, D.-L., Song, W.-D., Li, S.-H. & Yan, J.-B. (2010). Acta Cryst. E66, m1096–m1097.  Web of Science CSD CrossRef IUCr Journals Google Scholar
First citationLi, S. J., Song, W. D., Miao, D. L., Hu, S. W., Ji, L. L. & Ma, D. Y. (2011). Z. Anorg. Allg. Chem. 637, 1246–1252.  Web of Science CSD CrossRef CAS 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

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Volume 68| Part 4| April 2012| Pages m486-m487
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