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

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ISSN: 2056-9890
Volume 65| Part 7| July 2009| Pages m756-m757

catena-Poly[[bis­­(4-carb­oxy­cyclo­hexane­carboxyl­ato-κ2O1,O1′)cadmium(II)]-μ-1,4-bis­­(imidazol-1-ylmeth­yl)benzene-κ2N3:N3′]

aSchool of Environmental Science and Engineering, Huazhong University of Science and Technology, Wuhan 430074, People's Republic of China, and bDepartment of Bioengineering, Henan University of Urban Construction, Pingdingshan 467000, People's Republic of China
*Correspondence e-mail: libingbinghncj@yahoo.com.cn

(Received 25 May 2009; accepted 7 June 2009; online 10 June 2009)

In the title coordination polymer, [Cd(C8H11O4)2(C14H14N4)]n, the Cd atom (site symmetry 2) is six-coordin­ated by two O,O′-bidentate 4-carboxy­cyclo­hexa­necarboxyl­ate (Hchdc) ligands and two N atoms from two different 1,4-bis­(imidazol-1-ylmeth­yl)benzene (1,4-bix) mol­ecules in a very distorted cis-CdN2O4 octa­hedral environment. The 1,4-bix mol­ecules act as bridging ligands that bind two CdII atoms, thus forming an infinite chain propagating in [100], which is decorated by the Hchdc anions. The structure is completed by O—H⋯O hydrogen bonds, which link the chains together.

Related literature

For related structures, see: Qi et al. (2003[Qi, Y., Wang, Y., Hu, C., Cao, M., Mao, L. & Wang, E. (2003). Inorg. Chem. 42, 8519-8523.]). For background to coordination polymers, see: Chen & Liu (2002[Chen, X. M. & Liu, G. F. (2002). Chem. Eur. J. 8, 4811-4817.]); Fang et al. (2006[Fang, Q.-R., Zhu, G.-S., Xue, M., Zhang, Q.-L., Sun, J.-Y., Guo, X.-D., Qiu, S.-L., Xu, S.-T., Wang, P., Wang, D.-J., Wei, Y. (2006). Chem. Eur. J. 12, 3754-3758.]); Kim & Jung (2002[Kim, Y. J. & Jung, D.-Y. (2002). Chem. Commun. pp. 908-909.]); Lehn (1990[Lehn, J. M. (1990). Angew. Chem., Int. Ed. Engl. 29, 1304-1305.]); Batten & Robson (1998[Batten, S. R. & Robson, R. (1998). Angew. Chem. Int. Ed. 37, 1460-1494.]); Yang et al. (2008[Yang, J., Ma, J.-F., Batten, S. R. & Su, Z.-M. (2008). Chem. Commun. pp. 2233-2235.]).

[Scheme 1]

Experimental

Crystal data
  • [Cd(C8H11O4)2(C14H14N4)]

  • Mr = 693.03

  • Orthorhombic, P c c n

  • a = 12.6317 (5) Å

  • b = 19.9697 (12) Å

  • c = 12.3703 (7) Å

  • V = 3120.4 (3) Å3

  • Z = 4

  • Mo Kα radiation

  • μ = 0.75 mm−1

  • T = 292 K

  • 0.26 × 0.22 × 0.17 mm

Data collection
  • Oxford Diffraction Gemini R Ultra diffractometer

  • Absorption correction: multi-scan (CrysAlis RED; Oxford Diffraction, 2006[Oxford Diffraction (2006). CrysAlis CCD and CrysAlis RED. Oxford Diffraction Ltd, Abingdon, England.]) Tmin = 0.816, Tmax = 0.882

  • 26676 measured reflections

  • 3190 independent reflections

  • 1658 reflections with I > 2σ(I)

  • Rint = 0.116

Refinement
  • R[F2 > 2σ(F2)] = 0.052

  • wR(F2) = 0.120

  • S = 0.95

  • 3190 reflections

  • 195 parameters

  • H-atom parameters constrained

  • Δρmax = 0.62 e Å−3

  • Δρmin = −0.30 e Å−3

Table 1
Selected geometric parameters (Å, °)

Cd1—N1 2.249 (4)
Cd1—O1 2.306 (4)
Cd1—O2 2.384 (4)
O1—Cd1—O2 55.00 (14)

Table 2
Hydrogen-bond geometry (Å, °)

D—H⋯A D—H H⋯A DA D—H⋯A
O4—H4⋯O2i 0.82 1.86 2.644 (6) 161
Symmetry code: (i) [x+{\script{1\over 2}}, -y, -z+{\script{1\over 2}}].

Data collection: CrysAlis CCD (Oxford Diffraction, 2006[Oxford Diffraction (2006). CrysAlis CCD and CrysAlis RED. Oxford Diffraction Ltd, Abingdon, England.]); cell refinement: CrysAlis CCD; data reduction: CrysAlis RED (Oxford Diffraction, 2006[Oxford Diffraction (2006). CrysAlis CCD and CrysAlis RED. Oxford Diffraction Ltd, Abingdon, England.]); 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-Plus (Sheldrick, 2008[Sheldrick, G. M. (2008). Acta Cryst. A64, 112-122.]); software used to prepare material for publication: SHELXL97.

Supporting information


Comment top

The rational design and synthesis of metal-organic coordination polymers have received intense interest due to their fascinating structural topologies and potential applications as functional materials (e.g. Fang et al., 2006). These coordination polymers can be specially designed by the careful selection of metal cations with preferred coordination geometries, the nature of the anions, the structure of the connecting ligands, and the reaction conditions (Kim & Jung, 2002). The selection of ligand is extremely important because changing the structures of the ligands can control and adjust the topologies of coordination frameworks. Among these mentioned above, chain structures have received much attention in coordination chemistry and life sciecnce (Lehn, 1990). So far, many chain complexes have been generated by self-assembly processes (Chen & Liu, 2002). In this regard, metal 1,4-benzenedicarboxylates (1,4-bdc) have been widely studied (Qi et al., 2003). However, so far, less attention has been given to the 1,4-cyclohexanedicarboxylic acid ligand (H2chdc). The H2chdc as an important analogues of 1,4-bdc may be a good candidate for the construction of metal-organic architectures. On the other hand, 4,4'-byridine is a rigid rod-like spacer, well known in the construction of metal-organic polymers, and it has adopted numerous interesting supramolecular architectures (Batten & Robson, 1998). However, flexible ligands such as 1,4-bis(imidazole-1-ylmethyl)-benzene (1,4-bix) have not been so well explored to date (Yang et al., 2008). In this work, the combination of 1,4-bix with H2chdc and CdII cations resulted in the title compound [Cd(1,4-bix)(Hchdc)2], (I), a new one-dimensional chain coordination polymer.

The selected bond lengthes and angles are listed in Table 1. In compound (I), the CdII atom is is six-coordinated by four carboxylate O atoms from two different Hchdc ligands, and two N atoms from two different 1,4-bix molecules in a distorted octahedral environment (Fig. 1). The O1, O2, O2i and N1i atoms comprise the basal plane, whereas the N1 and O1i occupy the axial positions of the octahedron. As shown in Fig. 2, each 1,4-bix acts as a bridging ligand that binds two CdII atoms, thus forming a unique chain. The chain is decorated with Hchdc molecules alternately at two sides. Furthermore, the O—H···O hydrogen bonds link the chains together, stablizing the structure of (I).

Related literature top

For related structures, see: Qi et al. (2003). For background to coordination polymers, see: Chen & Liu (2002); Fang et al. (2006); Kim & Jung (2002); Lehn (1990); Batten & Robson (1998); Yang et al. (2008).

Experimental top

A mixture of CdCl2.2H2O (0.5 mmol), H2chdc acid (0.5 mmol), 1,4-bix (0.5 mmol), and H2O (500 mmol) was adjusted to pH = 5.8 by addition of aqueous NaOH solution, and heated at 453 K for 5 days. After the mixture was slowly cooled to room temperature, colorless blocks of (I) were recovered in a 28% yield.

Refinement top

The H atoms were positioned geometrically (C—H = 0.93–0.97 Å, O—H = 0.82Å) and refined as riding, with Uiso(H)=1.2Ueq(carrier).

Computing details top

Data collection: CrysAlis CCD (Oxford Diffraction, 2006); cell refinement: CrysAlis CCD (Oxford Diffraction, 2006); data reduction: CrysAlis RED (Oxford Diffraction, 2006); program(s) used to solve structure: SHELXS97 (Sheldrick, 2008); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008); molecular graphics: SHELXTL-Plus (Sheldrick, 2008); software used to prepare material for publication: SHELXL97 (Sheldrick, 2008).

Figures top
[Figure 1] Fig. 1. The structure of (I), showing displacement ellipsoids drawn at the 20% probability level. Symmetry code: (i) 3/2 - x, 1/2 - y, z; (ii) 5/2 - x, -1/2 - y, z.
[Figure 2] Fig. 2. View of the chain structure of (I).
catena-Poly[[bis(4-carboxycyclohexanecarboxylato- κ2O1,O1')cadmium(II)]-µ-1,4-bis(imidazol-1- ylmethyl)benzene-κ2N3:N3'] top
Crystal data top
[Cd(C8H11O4)2(C14H14N4)]F(000) = 1424
Mr = 693.03Dx = 1.475 Mg m3
Orthorhombic, PccnMo Kα radiation, λ = 0.71073 Å
Hall symbol: -P 2ab 2acCell parameters from 3190 reflections
a = 12.6317 (5) Åθ = 3.0–26.5°
b = 19.9697 (12) ŵ = 0.75 mm1
c = 12.3703 (7) ÅT = 292 K
V = 3120.4 (3) Å3Block, colorless
Z = 40.26 × 0.22 × 0.17 mm
Data collection top
Oxford Diffraction Gemini R Ultra
diffractometer
3190 independent reflections
Radiation source: fine-focus sealed tube1658 reflections with I > 2σ(I)
Graphite monochromatorRint = 0.116
Detector resolution: 10.0 pixels mm-1θmax = 26.5°, θmin = 4.7°
ω scansh = 1515
Absorption correction: multi-scan
(CrysAlis RED; Oxford Diffraction, 2006)
k = 2424
Tmin = 0.816, Tmax = 0.882l = 1515
26676 measured reflections
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)] = 0.052Hydrogen site location: inferred from neighbouring sites
wR(F2) = 0.120H-atom parameters constrained
S = 0.95 w = 1/[σ2(Fo2) + (0.0575P)2]
where P = (Fo2 + 2Fc2)/3
3190 reflections(Δ/σ)max < 0.001
195 parametersΔρmax = 0.62 e Å3
0 restraintsΔρmin = 0.30 e Å3
Crystal data top
[Cd(C8H11O4)2(C14H14N4)]V = 3120.4 (3) Å3
Mr = 693.03Z = 4
Orthorhombic, PccnMo Kα radiation
a = 12.6317 (5) ŵ = 0.75 mm1
b = 19.9697 (12) ÅT = 292 K
c = 12.3703 (7) Å0.26 × 0.22 × 0.17 mm
Data collection top
Oxford Diffraction Gemini R Ultra
diffractometer
3190 independent reflections
Absorption correction: multi-scan
(CrysAlis RED; Oxford Diffraction, 2006)
1658 reflections with I > 2σ(I)
Tmin = 0.816, Tmax = 0.882Rint = 0.116
26676 measured reflections
Refinement top
R[F2 > 2σ(F2)] = 0.0520 restraints
wR(F2) = 0.120H-atom parameters constrained
S = 0.95Δρmax = 0.62 e Å3
3190 reflectionsΔρmin = 0.30 e Å3
195 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
C10.7200 (5)0.1255 (3)0.1946 (5)0.0556 (16)
C20.7134 (5)0.0551 (3)0.1562 (5)0.0703 (18)
H20.64720.04950.11580.084*
C30.8075 (6)0.0347 (3)0.0813 (6)0.089 (2)
H3A0.80720.06270.01720.107*
H3B0.87380.04200.11900.107*
C40.7998 (7)0.0363 (4)0.0488 (6)0.106 (3)
H4A0.86060.04780.00450.127*
H4B0.73670.04270.00540.127*
C50.7956 (5)0.0833 (3)0.1467 (6)0.082 (2)
H50.77880.12810.11920.099*
C60.7065 (7)0.0639 (4)0.2243 (7)0.098 (2)
H6A0.63870.07290.19050.118*
H6B0.71130.09100.28910.118*
C70.7123 (6)0.0065 (3)0.2537 (6)0.089 (2)
H7A0.77580.01370.29610.107*
H7B0.65210.01720.29920.107*
C80.9032 (6)0.0881 (3)0.2022 (7)0.078 (2)
C90.9060 (3)0.2554 (3)0.4765 (4)0.0524 (13)
H90.88510.29970.48560.063*
C100.9221 (4)0.1567 (3)0.4138 (5)0.0657 (16)
H100.91520.11920.36990.079*
C110.9818 (5)0.1601 (3)0.5038 (5)0.0665 (18)
H111.02180.12580.53390.080*
C121.0206 (3)0.2510 (3)0.6389 (4)0.0612 (14)
H12A0.99620.22570.70100.073*
H12B0.99720.29690.64810.073*
C131.1951 (4)0.2506 (5)0.5441 (5)0.125 (4)
H131.15920.25210.47850.150*
C141.1390 (3)0.2497 (3)0.6368 (4)0.0479 (11)
C151.1954 (4)0.2499 (4)0.7277 (5)0.0693 (15)
H151.15990.24980.79360.083*
N10.8735 (3)0.2166 (2)0.3967 (4)0.0527 (11)
N20.9721 (3)0.2237 (2)0.5420 (4)0.0515 (12)
O10.7903 (3)0.1640 (2)0.1601 (3)0.0683 (11)
O20.6563 (3)0.1466 (2)0.2657 (4)0.0700 (12)
O30.9194 (5)0.0730 (3)0.2950 (5)0.120 (2)
O40.9764 (4)0.1119 (2)0.1406 (4)0.0951 (15)
H41.03230.11340.17410.143*
Cd10.75000.25000.27740 (4)0.04487 (19)
Atomic displacement parameters (Å2) top
U11U22U33U12U13U23
C10.062 (4)0.045 (3)0.059 (4)0.007 (3)0.007 (3)0.005 (3)
C20.096 (5)0.045 (3)0.069 (4)0.000 (3)0.000 (4)0.002 (3)
C30.149 (6)0.058 (4)0.061 (4)0.006 (4)0.036 (5)0.000 (4)
C40.118 (6)0.103 (6)0.096 (6)0.048 (5)0.013 (5)0.008 (5)
C50.085 (4)0.068 (4)0.093 (6)0.022 (4)0.020 (4)0.014 (4)
C60.095 (5)0.078 (5)0.123 (7)0.020 (4)0.014 (5)0.016 (5)
C70.111 (6)0.065 (4)0.092 (6)0.013 (4)0.027 (4)0.005 (4)
C80.089 (5)0.058 (4)0.087 (6)0.029 (4)0.001 (4)0.002 (4)
C90.036 (2)0.060 (3)0.062 (3)0.015 (3)0.002 (3)0.001 (4)
C100.067 (4)0.055 (4)0.075 (5)0.009 (3)0.018 (3)0.002 (3)
C110.060 (4)0.062 (4)0.077 (5)0.014 (3)0.018 (3)0.006 (3)
C120.037 (2)0.094 (4)0.052 (3)0.009 (4)0.006 (2)0.000 (4)
C130.042 (3)0.291 (12)0.042 (4)0.020 (7)0.008 (3)0.003 (6)
C140.040 (2)0.062 (3)0.042 (3)0.002 (3)0.001 (2)0.009 (4)
C150.048 (3)0.119 (5)0.041 (3)0.006 (5)0.004 (2)0.004 (5)
N10.039 (2)0.056 (3)0.064 (3)0.000 (2)0.007 (2)0.006 (3)
N20.030 (2)0.069 (3)0.056 (3)0.0009 (19)0.002 (2)0.006 (2)
O10.083 (3)0.058 (2)0.064 (3)0.001 (2)0.021 (2)0.004 (2)
O20.051 (2)0.059 (2)0.100 (3)0.0010 (18)0.015 (2)0.025 (2)
O30.143 (5)0.130 (5)0.088 (4)0.059 (4)0.019 (4)0.005 (4)
O40.077 (3)0.099 (4)0.110 (4)0.027 (3)0.007 (3)0.027 (3)
Cd10.0318 (2)0.0523 (3)0.0505 (3)0.0036 (3)0.0000.000
Geometric parameters (Å, º) top
C1—O11.250 (6)C9—N21.325 (7)
C1—O21.265 (6)C9—H90.9300
C1—C21.487 (8)C10—C111.347 (8)
C1—Cd12.716 (6)C10—N11.361 (6)
C2—C71.548 (8)C10—H100.9300
C2—C31.561 (8)C11—N21.360 (7)
C2—H20.9800C11—H110.9300
C3—C41.478 (9)C12—N21.453 (7)
C3—H3A0.9700C12—C141.496 (6)
C3—H3B0.9700C12—H12A0.9700
C4—C51.533 (10)C12—H12B0.9700
C4—H4A0.9700C13—C141.347 (7)
C4—H4B0.9700C13—C13i1.388 (11)
C5—C81.526 (9)C13—H130.9300
C5—C61.529 (9)C14—C151.331 (7)
C5—H50.9800C15—C15i1.379 (10)
C6—C71.453 (9)C15—H150.9300
C6—H6A0.9700O4—H40.8200
C6—H6B0.9700Cd1—N12.249 (4)
C7—H7A0.9700Cd1—O12.306 (4)
C7—H7B0.9700Cd1—O22.384 (4)
C8—O31.205 (8)Cd1—N1ii2.249 (4)
C8—O41.288 (8)Cd1—O1ii2.306 (4)
C9—N11.320 (7)Cd1—O2ii2.384 (4)
O1—C1—O2119.0 (5)C11—C10—N1109.7 (5)
O1—C1—C2120.8 (5)C11—C10—H10125.2
O2—C1—C2120.2 (6)N1—C10—H10125.2
C1—C2—C7110.2 (5)C10—C11—N2106.5 (5)
C1—C2—C3113.2 (5)C10—C11—H11126.8
C7—C2—C3107.8 (5)N2—C11—H11126.8
C1—C2—H2108.5N2—C12—C14113.6 (4)
C7—C2—H2108.5N2—C12—H12A108.8
C3—C2—H2108.5C14—C12—H12A108.8
C4—C3—C2111.2 (6)N2—C12—H12B108.8
C4—C3—H3A109.4C14—C12—H12B108.8
C2—C3—H3A109.4H12A—C12—H12B107.7
C4—C3—H3B109.4C14—C13—C13i121.7 (3)
C2—C3—H3B109.4C14—C13—H13119.2
H3A—C3—H3B108.0C13i—C13—H13119.2
C3—C4—C5112.0 (6)C15—C14—C13115.9 (4)
C3—C4—H4A109.2C15—C14—C12121.3 (4)
C5—C4—H4A109.2C13—C14—C12122.7 (5)
C3—C4—H4B109.2C14—C15—C15i122.4 (3)
C5—C4—H4B109.2C14—C15—H15118.8
H4A—C4—H4B107.9C15i—C15—H15118.8
C8—C5—C6112.9 (6)C9—N1—C10105.1 (5)
C8—C5—C4111.2 (6)C9—N1—Cd1122.2 (4)
C6—C5—C4111.5 (6)C10—N1—Cd1132.5 (4)
C8—C5—H5106.9C9—N2—C11106.9 (5)
C6—C5—H5106.9C9—N2—C12126.2 (5)
C4—C5—H5106.9C11—N2—C12126.8 (5)
C7—C6—C5111.5 (6)C1—O1—Cd194.9 (3)
C7—C6—H6A109.3C1—O2—Cd190.9 (3)
C5—C6—H6A109.3C8—O4—H4109.5
C7—C6—H6B109.3N1—Cd1—N1ii97.9 (2)
C5—C6—H6B109.3N1—Cd1—O192.24 (16)
H6A—C6—H6B108.0N1ii—Cd1—O1141.92 (15)
C6—C7—C2114.3 (6)N1—Cd1—O1ii141.92 (15)
C6—C7—H7A108.7N1ii—Cd1—O1ii92.24 (16)
C2—C7—H7A108.7O1—Cd1—O1ii102.0 (2)
C6—C7—H7B108.7N1—Cd1—O297.33 (15)
C2—C7—H7B108.7N1ii—Cd1—O287.24 (15)
H7A—C7—H7B107.6O1—Cd1—O255.00 (14)
O3—C8—O4122.2 (7)O1ii—Cd1—O2119.83 (15)
O3—C8—C5124.4 (7)N1—Cd1—O2ii87.24 (15)
O4—C8—C5113.3 (7)N1ii—Cd1—O2ii97.33 (15)
N1—C9—N2111.8 (6)O1—Cd1—O2ii119.83 (15)
N1—C9—H9124.1O1ii—Cd1—O2ii55.00 (14)
N2—C9—H9124.1O2—Cd1—O2ii173.1 (2)
Symmetry codes: (i) x+5/2, y+1/2, z; (ii) x+3/2, y+1/2, z.
Hydrogen-bond geometry (Å, º) top
D—H···AD—HH···AD···AD—H···A
O4—H4···O2iii0.821.862.644 (6)161
Symmetry code: (iii) x+1/2, y, z+1/2.

Experimental details

Crystal data
Chemical formula[Cd(C8H11O4)2(C14H14N4)]
Mr693.03
Crystal system, space groupOrthorhombic, Pccn
Temperature (K)292
a, b, c (Å)12.6317 (5), 19.9697 (12), 12.3703 (7)
V3)3120.4 (3)
Z4
Radiation typeMo Kα
µ (mm1)0.75
Crystal size (mm)0.26 × 0.22 × 0.17
Data collection
DiffractometerOxford Diffraction Gemini R Ultra
diffractometer
Absorption correctionMulti-scan
(CrysAlis RED; Oxford Diffraction, 2006)
Tmin, Tmax0.816, 0.882
No. of measured, independent and
observed [I > 2σ(I)] reflections
26676, 3190, 1658
Rint0.116
(sin θ/λ)max1)0.627
Refinement
R[F2 > 2σ(F2)], wR(F2), S 0.052, 0.120, 0.95
No. of reflections3190
No. of parameters195
H-atom treatmentH-atom parameters constrained
Δρmax, Δρmin (e Å3)0.62, 0.30

Computer programs: CrysAlis CCD (Oxford Diffraction, 2006), CrysAlis RED (Oxford Diffraction, 2006), SHELXS97 (Sheldrick, 2008), SHELXL97 (Sheldrick, 2008), SHELXTL-Plus (Sheldrick, 2008).

Selected geometric parameters (Å, º) top
Cd1—N12.249 (4)Cd1—O22.384 (4)
Cd1—O12.306 (4)
O1—Cd1—O255.00 (14)
Hydrogen-bond geometry (Å, º) top
D—H···AD—HH···AD···AD—H···A
O4—H4···O2i0.821.862.644 (6)161
Symmetry code: (i) x+1/2, y, z+1/2.
 

Acknowledgements

The authors thank Henan University of Urban Construction for support of this work.

References

First citationBatten, S. R. & Robson, R. (1998). Angew. Chem. Int. Ed. 37, 1460–1494.  Web of Science CrossRef Google Scholar
First citationChen, X. M. & Liu, G. F. (2002). Chem. Eur. J. 8, 4811–4817.  CrossRef PubMed CAS Google Scholar
First citationFang, Q.-R., Zhu, G.-S., Xue, M., Zhang, Q.-L., Sun, J.-Y., Guo, X.-D., Qiu, S.-L., Xu, S.-T., Wang, P., Wang, D.-J., Wei, Y. (2006). Chem. Eur. J. 12, 3754-3758.  Web of Science CrossRef PubMed CAS Google Scholar
First citationKim, Y. J. & Jung, D.-Y. (2002). Chem. Commun. pp. 908–909.  Web of Science CSD CrossRef Google Scholar
First citationLehn, J. M. (1990). Angew. Chem., Int. Ed. Engl. 29, 1304–1305.  Google Scholar
First citationOxford Diffraction (2006). CrysAlis CCD and CrysAlis RED. Oxford Diffraction Ltd, Abingdon, England.  Google Scholar
First citationQi, Y., Wang, Y., Hu, C., Cao, M., Mao, L. & Wang, E. (2003). Inorg. Chem. 42, 8519–8523.  Web of Science CSD CrossRef PubMed CAS Google Scholar
First citationSheldrick, G. M. (2008). Acta Cryst. A64, 112–122.  Web of Science CrossRef CAS IUCr Journals Google Scholar
First citationYang, J., Ma, J.-F., Batten, S. R. & Su, Z.-M. (2008). Chem. Commun. pp. 2233–2235.  Web of Science CSD CrossRef Google Scholar

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Volume 65| Part 7| July 2009| Pages m756-m757
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