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

Journal logoCRYSTALLOGRAPHIC
COMMUNICATIONS
ISSN: 2056-9890
Volume 65| Part 4| April 2009| Pages m355-m356

Poly[(μ2-2-hydr­­oxy-2-methyl­propionato-κ3O1,O2:O1′)(μ2-2-hydr­­oxy-2-methyl­propionato-κ2O1:κO1′)dioxido­uranium(VI)]

aDepartment of Chemistry, Graduate School of Science, Osaka University, Toyonaka, Osaka 560-0043, Japan
*Correspondence e-mail: tyoshi@chem.sci.osaka-u.ac.jp

(Received 15 February 2009; accepted 19 February 2009; online 6 March 2009)

In the title compound, [UO2(C4H7O3)2]n, the dioxouranium(VI) units are linked by 2-hydr­oxy-2-methyl­propionate ligands into a honeycomb structure. The U atom is seven-coordinate in a penta­gonal-bipyramidal geometry. The uncoordinated hydr­oxy groups of the 2-hydr­oxy-2-methyl­propionate ions inter­act with the O atom of the uranyl and with the coordinated hydr­oxy group of an adjacent 2-hydr­oxy-2-methyl­propionate ion through O—H⋯O hydrogen bonds.

Related literature

For related structures, see: Back et al. (2007[Back, D. F., Manzoni de Oliveira, G. & Schulz Lang, E. (2007). Z. Anorg. Allg. Chem. 633, 729-733.]); Bombieri et al. (1973[Bombieri, G., Graziani, R. & Forsellini, E. (1973). Inorg. Nucl. Chem. Lett. 9, 551-557.], 1974[Bombieri, G., Croatto, U., Graziani, R., Forsellini, E. & Magon, L. (1974). Acta Cryst. B30, 407-411.]); Jiang et al. (2002[Jiang, J., Sarsfield, M. J., Renshaw, J. C., Livens, F. R., Collison, D., Charnock, J. M., Helliwell, M. & Eccles, H. (2002). Inorg. Chem. 41, 2799-2806.]); Thuéry (2006[Thuéry, P. (2006). Chem. Commun. pp. 853-855.], 2007a[Thuéry, P. (2007a). CrystEngComm, 9, 358-360.],b[Thuéry, P. (2007b). Inorg. Chem. 46, 2307-2315.],c[Thuéry, P. (2007c). Polyhedron, 26, 101-106.], 2008[Thuéry, P. (2008). CrystEngComm, 10, 79-85.]); Xie et al. (2003[Xie, Y.-R., Zhao, H., Wang, X.-S., Qu, Z.-R., Xiong, R.-G., Xue, X., Xue, Z. & You, X.-Z. (2003). Eur. J. Inorg. Chem. pp. 3712-3715.]); Yokoyama et al. (1990[Yokoyama, Y., Inaba, A., Hara, H., Yamazaki, T., Tamura, H. & Kushi, Y. (1990). Chem. Lett. pp. 671-674.]).

[Scheme 1]

Experimental

Crystal data
  • [U(C4H7O3)2O2]

  • Mr = 476.22

  • Monoclinic, P 21 /n

  • a = 9.009 (2) Å

  • b = 8.237 (2) Å

  • c = 17.552 (6) Å

  • β = 98.246 (9)°

  • V = 1289.0 (6) Å3

  • Z = 4

  • Mo Kα radiation

  • μ = 12.62 mm−1

  • T = 200 K

  • 0.20 × 0.11 × 0.03 mm

Data collection
  • Rigaku R-AXIS RAPID Imaging Plate diffractometer

  • Absorption correction: multi-scan (ABSCOR; Higashi, 1995[Higashi, T. (1995). ABSCOR. Rigaku Corporation, Tokyo, Japan.]) Tmin = 0.233, Tmax = 0.685

  • 11887 measured reflections

  • 2949 independent reflections

  • 2547 reflections with I > 2σ(I)

  • Rint = 0.050

Refinement
  • R[F2 > 2σ(F2)] = 0.029

  • wR(F2) = 0.100

  • S = 0.86

  • 2949 reflections

  • 160 parameters

  • H-atom parameters constrained

  • Δρmax = 0.99 e Å−3

  • Δρmin = −2.15 e Å−3

Table 1
Selected bond lengths (Å)

U1—O1 1.783 (5)
U1—O2 1.762 (6)
U1—O3 2.444 (5)
U1—O4 2.407 (5)
U1—O5i 2.355 (4)
U1—O7 2.346 (5)
U1—O7 2.336 (5)
Symmetry code: (i) [-x+{\script{3\over 2}}, y-{\script{1\over 2}}, -z+{\script{3\over 2}}].

Table 2
Hydrogen-bond geometry (Å, °)

D—H⋯A D—H H⋯A DA D—H⋯A
O3—H13⋯O6 0.82 1.93 2.597 (6) 138
O6—H14⋯O1ii 0.82 2.00 2.777 (6) 158
Symmetry code: (ii) -x+1, -y+1, -z+1.

Data collection: PROCESS-AUTO (Rigaku, 1998[Rigaku (1998). PROCESS-AUTO. Rigaku Corporation, Tokyo, Japan.]); cell refinement: PROCESS-AUTO; data reduction: TEXSAN (Rigaku/MSC, 2004[Rigaku/MSC (2004). TEXSAN. Rigaku/MSC, The Woodlands, Texas, USA.]); program(s) used to solve structure: SIR92 (Altomare et al., 1994[Altomare, A., Cascarano, G., Giacovazzo, C., Guagliardi, A., Burla, M. C., Polidori, G. & Camalli, M. (1994). J. Appl. Cryst. 27, 435.]); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008[Sheldrick, G. M. (2008). Acta Cryst. A64, 112-122.]); molecular graphics: ORTEP-3 (Farrugia, 1997[Farrugia, L. J. (1997). J. Appl. Cryst. 30, 565.]) and Mercury (Macrae et al., 2006[Macrae, C. F., Edgington, P. R., McCabe, P., Pidcock, E., Shields, G. P., Taylor, R., Towler, M. & van de Streek, J. (2006). J. Appl. Cryst. 39, 453-457.]); software used to prepare material for publication: TEXSAN.

Supporting information


Comment top

Structural chemistry of uranyl(VI) complexes with hydroxycarboxylate or alkoxycarboxylate has been extensively studied (Back et al. (2007); Bombieri et al.(1973, 1974); Jiang et al. (2002); Thuéry (2006, 2007a,b,c, 2008); Xie et al. (2003); Yokoyama et al.(1990)). The crystals of the title compound (I) suitable for single-crystal X-ray analysis were obtained by the reaction of bis(acetato)dioxouranium dihydrate with an excess amount of 2-hydroxy-2-methylpropionic acid in water. Herein, we report on the crystal structure of I. Uranium(VI) atom is seven-coordinate in a pentagonal-bipyramidal structure. The two oxygen atoms are located at the axial positions with nearly linear O(1)—U(1)—O(2) angle (178.3 (2)°). The equatorial positions are coordinated by five oxygen atoms of 2-hydroxy-2-methylpropionate (HIB) ligands. Two kinds of HIB ligands exist in the asymmetric unit. One of the HIB ligands links two uranium atoms by the carboxyl group. The other chelates one uranium atom through the hydroxy and carboxyl groups, moreover the carboxyl group bridges the neighboring uranium atom. As a result, a two-dimensional honeycomb structure is formed. The IR spectrum of I shows stretching bands of the carboxyl group of HIB at 1614 and 1561 cm-1.

Related literature top

For related structures, see: Back et al. (2007); Bombieri et al. (1973, 1974); Jiang et al. (2002); Thuéry (2006, 2007a,b,c, 2008); Xie et al. (2003); Yokoyama et al. (1990).

Experimental top

2-Hydroxy-2-methylpropionic acid (150 mg, 1.45 mmol) was added to a solution of bis(acetato)dioxouranium dihydrate (50 mg, 0.12 mmol) in 3 ml of water. The resulting yellow solution was left for several days at room temperature to give yellow crystals, which were filtered off, washed with a small amount of water, and then dried in air.

Refinement top

H atoms bonded to C and O atoms were placed at calculated positions [C—H = 0.96 and O—H = 0.82] and refined as riding with Uiso(H) = 1.0 Ueq(C,O). The deepest hole is 0.68 Å from atom U(1).

Computing details top

Data collection: PROCESS-AUTO (Rigaku, 1998); cell refinement: PROCESS-AUTO (Rigaku, 1998); data reduction: TEXSAN (Rigaku/MSC, 2004); program(s) used to solve structure: SIR92 (Altomare et al., 1994); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008); molecular graphics: ORTEP-3 (Farrugia, 1997) and Mercury (Macrae et al., 2006); software used to prepare material for publication: TEXSAN (Rigaku/MSC, 2004).

Figures top
[Figure 1] Fig. 1. The assymmetric unit of I, with the atom-numbering scheme and displacement ellipsoids drawn at 50% probability level. Hydrogen atoms are omitted for clarity.
[Figure 2] Fig. 2. Fragment of the polymeric structure. Hydrogen atoms are omitted for clarity.
[Figure 3] Fig. 3. View of the polymeric structure. Hydrogen atoms are omitted for clarity.
Poly[(µ2-2-hydroxy-2-methylpropionato- κ3O1,O2:O1')(µ2-2-hydroxy-2- methylpropionato-κ2O1:κO1')dioxidouranium(VI)] top
Crystal data top
[U(C4H7O3)2O2]F(000) = 872.00
Mr = 476.22Dx = 2.454 Mg m3
Monoclinic, P21/nMo Kα radiation, λ = 0.7107 Å
Hall symbol: -P 2ynCell parameters from 8716 reflections
a = 9.009 (2) Åθ = 3.0–27.5°
b = 8.237 (2) ŵ = 12.62 mm1
c = 17.552 (6) ÅT = 200 K
β = 98.246 (9)°Platelet, yellow
V = 1289.0 (6) Å30.20 × 0.11 × 0.03 mm
Z = 4
Data collection top
Rigaku R-AXIS RAPID Imaging Plate
diffractometer
2949 independent reflections
Radiation source: fine-focus sealed tube2547 reflections with I > 2σ(I)
Graphite monochromatorRint = 0.050
Detector resolution: 10.00 pixels mm-1θmax = 27.5°, θmin = 3.0°
ω scansh = 1211
Absorption correction: multi-scan
(ABSCOR; Higashi, 1995)
k = 910
Tmin = 0.233, Tmax = 0.685l = 2222
11887 measured reflections
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)] = 0.029H-atom parameters constrained
wR(F2) = 0.100 w = 1/[σ2(Fo2) + (0.079P)2 + 5.354P]
where P = (Fo2 + 2Fc2)/3
S = 0.86(Δ/σ)max = 0.001
2949 reflectionsΔρmax = 0.99 e Å3
160 parametersΔρmin = 2.15 e Å3
Primary atom site location: structure-invariant direct methods
Crystal data top
[U(C4H7O3)2O2]V = 1289.0 (6) Å3
Mr = 476.22Z = 4
Monoclinic, P21/nMo Kα radiation
a = 9.009 (2) ŵ = 12.62 mm1
b = 8.237 (2) ÅT = 200 K
c = 17.552 (6) Å0.20 × 0.11 × 0.03 mm
β = 98.246 (9)°
Data collection top
Rigaku R-AXIS RAPID Imaging Plate
diffractometer
2949 independent reflections
Absorption correction: multi-scan
(ABSCOR; Higashi, 1995)
2547 reflections with I > 2σ(I)
Tmin = 0.233, Tmax = 0.685Rint = 0.050
11887 measured reflections
Refinement top
R[F2 > 2σ(F2)] = 0.029160 parameters
wR(F2) = 0.100H-atom parameters constrained
S = 0.86Δρmax = 0.99 e Å3
2949 reflectionsΔρmin = 2.15 e Å3
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
U(1)0.63772 (2)0.19668 (3)0.62425 (1)0.0180 (1)
O(1)0.7538 (6)0.3101 (5)0.5695 (3)0.028 (1)
O(2)0.5188 (6)0.0891 (6)0.6778 (3)0.032 (1)
O(3)0.4753 (5)0.4342 (5)0.6250 (3)0.026 (1)
O(4)0.6920 (5)0.3869 (6)0.7286 (3)0.029 (1)
O(5)0.6435 (5)0.6018 (6)0.7991 (3)0.0252 (10)
O(6)0.2338 (5)0.4208 (5)0.5248 (3)0.0241 (10)
O(7)0.7009 (6)0.0415 (6)0.5630 (3)0.034 (1)
O(8)0.4514 (6)0.1975 (5)0.5169 (3)0.030 (1)
C(1)0.6115 (7)0.5015 (8)0.7435 (3)0.022 (1)
C(2)0.4611 (7)0.5295 (8)0.6929 (4)0.021 (1)
C(3)0.3351 (8)0.463 (1)0.7324 (4)0.036 (2)
C(4)0.4392 (10)0.7064 (7)0.6704 (5)0.030 (2)
C(5)0.3241 (7)0.1601 (8)0.4820 (4)0.020 (1)
C(6)0.1889 (7)0.2626 (8)0.4949 (4)0.021 (1)
C(7)0.1191 (10)0.1790 (9)0.5588 (5)0.039 (2)
C(8)0.0781 (10)0.280 (1)0.4211 (5)0.038 (2)
H(1)0.32770.52530.77790.0356*
H(2)0.24230.46980.69800.0356*
H(3)0.35550.35160.74620.0356*
H(4)0.43880.77110.71590.0297*
H(5)0.34540.71920.63740.0297*
H(6)0.51960.74090.64380.0297*
H(7)0.03210.23840.56840.0386*
H(8)0.19080.17570.60480.0386*
H(9)0.09070.07030.54320.0386*
H(10)0.01000.33590.43220.0383*
H(11)0.05070.17460.40070.0383*
H(12)0.12370.34130.38410.0383*
H(13)0.42100.47240.58780.0255*
H(14)0.21780.48830.49020.0241*
Atomic displacement parameters (Å2) top
U11U22U33U12U13U23
U(1)0.0192 (2)0.0158 (2)0.0185 (2)0.00083 (8)0.0005 (1)0.00114 (8)
O(1)0.022 (3)0.030 (3)0.032 (3)0.007 (2)0.004 (2)0.007 (2)
O(2)0.029 (3)0.025 (2)0.044 (3)0.005 (2)0.009 (2)0.007 (2)
O(3)0.034 (3)0.022 (2)0.017 (2)0.008 (2)0.008 (2)0.005 (2)
O(4)0.029 (3)0.025 (2)0.030 (2)0.007 (2)0.004 (2)0.006 (2)
O(5)0.028 (2)0.027 (2)0.020 (2)0.008 (2)0.001 (2)0.010 (2)
O(6)0.030 (2)0.016 (2)0.023 (2)0.002 (2)0.005 (2)0.001 (2)
O(7)0.032 (3)0.027 (3)0.038 (3)0.009 (2)0.008 (2)0.018 (2)
O(8)0.023 (3)0.033 (3)0.033 (3)0.005 (2)0.002 (2)0.008 (2)
C(1)0.023 (3)0.024 (3)0.017 (3)0.007 (3)0.000 (2)0.001 (3)
C(2)0.027 (3)0.016 (3)0.020 (3)0.000 (3)0.000 (2)0.008 (2)
C(3)0.032 (4)0.042 (4)0.035 (4)0.012 (3)0.009 (3)0.013 (3)
C(4)0.040 (4)0.015 (3)0.032 (4)0.004 (3)0.001 (3)0.004 (3)
C(5)0.022 (3)0.019 (3)0.020 (3)0.009 (3)0.001 (2)0.002 (3)
C(6)0.021 (3)0.018 (3)0.022 (3)0.013 (3)0.003 (2)0.003 (3)
C(7)0.035 (4)0.036 (4)0.048 (5)0.015 (3)0.017 (4)0.005 (3)
C(8)0.035 (4)0.035 (4)0.040 (4)0.014 (3)0.012 (4)0.004 (4)
Geometric parameters (Å, º) top
U(1)—O(1)1.783 (5)C(2)—C(4)1.514 (9)
U(1)—O(2)1.762 (6)C(3)—H(1)0.960
U(1)—O(3)2.444 (5)C(3)—H(2)0.960
U(1)—O(4)2.407 (5)C(3)—H(3)0.960
U(1)—O(5)i2.355 (4)C(4)—H(4)0.960
U(1)—O(7)2.346 (5)C(4)—H(5)0.960
U(1)—O(8)2.336 (5)C(4)—H(6)0.960
O(3)—C(2)1.449 (8)C(5)—C(6)1.525 (10)
O(3)—H(13)0.820C(6)—C(7)1.53 (1)
O(4)—C(1)1.241 (8)C(6)—C(8)1.523 (10)
O(5)—C(1)1.280 (8)C(7)—H(7)0.960
O(6)—C(6)1.441 (8)C(7)—H(8)0.960
O(6)—H(14)0.820C(7)—H(9)0.960
O(7)—C(5)ii1.257 (8)C(8)—H(10)0.960
O(8)—C(5)1.259 (8)C(8)—H(11)0.960
C(1)—C(2)1.528 (8)C(8)—H(12)0.960
C(2)—C(3)1.51 (1)
O(1)—U(1)—O(2)178.3 (2)C(1)—C(2)—C(4)111.6 (6)
O(1)—U(1)—O(3)88.9 (2)C(3)—C(2)—C(4)112.9 (6)
O(1)—U(1)—O(4)89.9 (2)C(2)—C(3)—H(1)109.5
O(1)—U(1)—O(5)i88.5 (2)C(2)—C(3)—H(2)109.5
O(1)—U(1)—O(7)89.5 (2)C(2)—C(3)—H(3)109.5
O(1)—U(1)—O(8)88.5 (2)H(1)—C(3)—H(2)109.5
O(2)—U(1)—O(3)89.4 (2)H(1)—C(3)—H(3)109.5
O(2)—U(1)—O(4)89.7 (2)H(2)—C(3)—H(3)109.5
O(2)—U(1)—O(5)i93.0 (2)C(2)—C(4)—H(4)109.5
O(2)—U(1)—O(7)91.7 (2)C(2)—C(4)—H(5)109.5
O(2)—U(1)—O(8)90.6 (2)C(2)—C(4)—H(6)109.5
O(3)—U(1)—O(4)62.1 (1)H(4)—C(4)—H(5)109.5
O(3)—U(1)—O(5)i135.7 (2)H(4)—C(4)—H(6)109.5
O(3)—U(1)—O(7)148.9 (2)H(5)—C(4)—H(6)109.5
O(3)—U(1)—O(8)68.9 (2)O(7)ii—C(5)—O(8)124.4 (6)
O(4)—U(1)—O(5)i73.7 (2)O(7)ii—C(5)—C(6)116.7 (6)
O(4)—U(1)—O(7)149.0 (2)O(8)—C(5)—C(6)119.0 (6)
O(4)—U(1)—O(8)131.0 (2)O(6)—C(6)—C(5)111.4 (5)
O(5)i—U(1)—O(7)75.3 (2)O(6)—C(6)—C(7)105.3 (5)
O(5)i—U(1)—O(8)155.1 (2)O(6)—C(6)—C(8)109.8 (6)
O(7)—U(1)—O(8)80.0 (2)C(5)—C(6)—C(7)106.3 (6)
U(1)—O(3)—C(2)124.2 (3)C(5)—C(6)—C(8)111.5 (6)
U(1)—O(3)—H(13)126.3C(7)—C(6)—C(8)112.2 (6)
C(2)—O(3)—H(13)109.5C(6)—C(7)—H(7)109.5
U(1)—O(4)—C(1)126.5 (4)C(6)—C(7)—H(8)109.5
U(1)iii—O(5)—C(1)136.7 (4)C(6)—C(7)—H(9)109.5
C(6)—O(6)—H(14)109.5H(7)—C(7)—H(8)109.5
U(1)—O(7)—C(5)ii154.9 (4)H(7)—C(7)—H(9)109.5
U(1)—O(8)—C(5)153.0 (5)H(8)—C(7)—H(9)109.5
O(4)—C(1)—O(5)125.3 (6)C(6)—C(8)—H(10)109.5
O(4)—C(1)—C(2)119.3 (5)C(6)—C(8)—H(11)109.5
O(5)—C(1)—C(2)115.4 (6)C(6)—C(8)—H(12)109.5
O(3)—C(2)—C(1)102.7 (5)H(10)—C(8)—H(11)109.5
O(3)—C(2)—C(3)109.9 (5)H(10)—C(8)—H(12)109.5
O(3)—C(2)—C(4)109.3 (5)H(11)—C(8)—H(12)109.5
C(1)—C(2)—C(3)109.9 (5)
Symmetry codes: (i) x+3/2, y1/2, z+3/2; (ii) x+1, y, z+1; (iii) x+3/2, y+1/2, z+3/2.
Hydrogen-bond geometry (Å, º) top
D—H···AD—HH···AD···AD—H···A
O(3)—H(13)···O(6)0.8201.9272.597 (6)138.188
O(6)—H(14)···O(1)iv0.8201.9992.777 (6)158.201
Symmetry code: (iv) x+1, y+1, z+1.

Experimental details

Crystal data
Chemical formula[U(C4H7O3)2O2]
Mr476.22
Crystal system, space groupMonoclinic, P21/n
Temperature (K)200
a, b, c (Å)9.009 (2), 8.237 (2), 17.552 (6)
β (°) 98.246 (9)
V3)1289.0 (6)
Z4
Radiation typeMo Kα
µ (mm1)12.62
Crystal size (mm)0.20 × 0.11 × 0.03
Data collection
DiffractometerRigaku R-AXIS RAPID Imaging Plate
diffractometer
Absorption correctionMulti-scan
(ABSCOR; Higashi, 1995)
Tmin, Tmax0.233, 0.685
No. of measured, independent and
observed [I > 2σ(I)] reflections
11887, 2949, 2547
Rint0.050
(sin θ/λ)max1)0.649
Refinement
R[F2 > 2σ(F2)], wR(F2), S 0.029, 0.100, 0.86
No. of reflections2949
No. of parameters160
No. of restraints?
H-atom treatmentH-atom parameters constrained
Δρmax, Δρmin (e Å3)0.99, 2.15

Computer programs: PROCESS-AUTO (Rigaku, 1998), TEXSAN (Rigaku/MSC, 2004), SIR92 (Altomare et al., 1994), SHELXL97 (Sheldrick, 2008), ORTEP-3 (Farrugia, 1997) and Mercury (Macrae et al., 2006).

Selected bond lengths (Å) top
U(1)—O(1)1.783 (5)U(1)—O(5)i2.355 (4)
U(1)—O(2)1.762 (6)U(1)—O(7)2.346 (5)
U(1)—O(3)2.444 (5)U(1)—O(8)2.336 (5)
U(1)—O(4)2.407 (5)
Symmetry code: (i) x+3/2, y1/2, z+3/2.
Hydrogen-bond geometry (Å, º) top
D—H···AD—HH···AD···AD—H···A
O(3)—H(13)···O(6)0.8201.9272.597 (6)138.188
O(6)—H(14)···O(1)ii0.8201.9992.777 (6)158.201
Symmetry code: (ii) x+1, y+1, z+1.
 

Acknowledgements

The present study is the result of the efficient separation and analysis of nuclear fission products for reprocessing systems entrusted to Osaka University by the Ministry of Education, Culture, Sports, Science and Technology of Japan (MEXT).

References

First citationAltomare, A., Cascarano, G., Giacovazzo, C., Guagliardi, A., Burla, M. C., Polidori, G. & Camalli, M. (1994). J. Appl. Cryst. 27, 435.  CrossRef Web of Science IUCr Journals Google Scholar
First citationBack, D. F., Manzoni de Oliveira, G. & Schulz Lang, E. (2007). Z. Anorg. Allg. Chem. 633, 729–733.  Web of Science CSD CrossRef CAS Google Scholar
First citationBombieri, G., Croatto, U., Graziani, R., Forsellini, E. & Magon, L. (1974). Acta Cryst. B30, 407–411.  CSD CrossRef CAS IUCr Journals Web of Science Google Scholar
First citationBombieri, G., Graziani, R. & Forsellini, E. (1973). Inorg. Nucl. Chem. Lett. 9, 551–557.  CSD CrossRef CAS Web of Science Google Scholar
First citationFarrugia, L. J. (1997). J. Appl. Cryst. 30, 565.  CrossRef IUCr Journals Google Scholar
First citationHigashi, T. (1995). ABSCOR. Rigaku Corporation, Tokyo, Japan.  Google Scholar
First citationJiang, J., Sarsfield, M. J., Renshaw, J. C., Livens, F. R., Collison, D., Charnock, J. M., Helliwell, M. & Eccles, H. (2002). Inorg. Chem. 41, 2799–2806.  Web of Science CSD CrossRef PubMed CAS Google Scholar
First citationMacrae, C. F., Edgington, P. R., McCabe, P., Pidcock, E., Shields, G. P., Taylor, R., Towler, M. & van de Streek, J. (2006). J. Appl. Cryst. 39, 453–457.  Web of Science CrossRef CAS IUCr Journals Google Scholar
First citationRigaku (1998). PROCESS-AUTO. Rigaku Corporation, Tokyo, Japan.  Google Scholar
First citationRigaku/MSC (2004). TEXSAN. Rigaku/MSC, The Woodlands, Texas, USA.  Google Scholar
First citationSheldrick, G. M. (2008). Acta Cryst. A64, 112–122.  Web of Science CrossRef CAS IUCr Journals Google Scholar
First citationThuéry, P. (2006). Chem. Commun. pp. 853–855.  Google Scholar
First citationThuéry, P. (2007a). CrystEngComm, 9, 358–360.  Google Scholar
First citationThuéry, P. (2007b). Inorg. Chem. 46, 2307–2315.  Web of Science PubMed Google Scholar
First citationThuéry, P. (2007c). Polyhedron, 26, 101–106.  Google Scholar
First citationThuéry, P. (2008). CrystEngComm, 10, 79–85.  Google Scholar
First citationXie, Y.-R., Zhao, H., Wang, X.-S., Qu, Z.-R., Xiong, R.-G., Xue, X., Xue, Z. & You, X.-Z. (2003). Eur. J. Inorg. Chem. pp. 3712–3715.  Web of Science CSD CrossRef Google Scholar
First citationYokoyama, Y., Inaba, A., Hara, H., Yamazaki, T., Tamura, H. & Kushi, Y. (1990). Chem. Lett. pp. 671–674.  CrossRef Web of Science Google Scholar

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Volume 65| Part 4| April 2009| Pages m355-m356
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