metal-organic compounds
catena-Poly[[aquadioxidouranium(VI)]-μ3-4,4′-oxydibenzoato]
aState Key Laboratory of Inorganic Synthesis and Preparative Chemistry, College of Chemistry, Jilin University, Changchun 130012, People's Republic of China
*Correspondence e-mail: zhangping@jlu.edu.cn.
The title compound, [UO2(C14H8O5)(H2O)]n, is a polymeric UO2 complex bridged by 4,4′-oxydibenzoate ligands. One carboxylate group of the bridging ligand chelates a uranyl cation while the other carboxylate group of the ligand bridges two other two uranyl cations, forming a double-chain polymeric structure. The central UVI atom is seven-coordinated in a distorted UO7 pentagonal-bipyramidal geometry. In the O—H⋯O hydrogen bonding links the polymeric chains into a three-dimensional supramolecular framework. Within the bridging ligand, the two benzene rings are oriented at a dihedral angle of 59.0 (2)°.
Related literature
For the potential applications of porous uranyl-organic frameworks, see: Thuéry & Masci (2008); Cahill et al. (2007); Masci & Thuéry (2008). For a related structure, see: Yu et al. (2004).
Experimental
Crystal data
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Refinement
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Data collection: RAPID-AUTO (Rigaku, 1998); cell RAPID-AUTO; data reduction: CrystalClear (Rigaku/MSC, 2002); program(s) used to solve structure: SHELXS97 (Sheldrick, 2008); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008); molecular graphics: ORTEP-3 for Windows (Farrugia, 1997); software used to prepare material for publication: WinGX (Farrugia, 1999).
Supporting information
10.1107/S1600536810010639/xu2712sup1.cif
contains datablocks I, global. DOI:Structure factors: contains datablock I. DOI: 10.1107/S1600536810010639/xu2712Isup2.hkl
For the preparation of the title compound, a mixture of uranium oxynitrate hexahydrate (0.1025 g, 0.21 mmol), 4,4'-oxybis(benzoic acid) (0.1092 g, 0.42 mmol), potassium hydroxide (0.0470 g, 0.84 mmol) and 6 mL water was sealed in a 23 mLstainless steel reactor with a Teflon liner. The reaction system was heated at 423 K for 48 h, and then cooled slowly to room temperature. A large number of pale-yellow crystals of the title compound were obtained and collected by filtration, washed with water and dried in air.
H atoms bound to C atoms were placed in calculated positions and treated as riding on their parent atoms, with C—H = 0.93 Å (aromatic) and with Uiso(H) = 1.2Ueq(C). Water H atoms were initially located in a difference Fourier map, but they were treated as riding on their parent atoms with O—H = 0.85 Å and with Uiso(H) = 1.5Ueq(O).
Data collection: RAPID-AUTO (Rigaku, 1998); cell
RAPID-AUTO (Rigaku, 1998); data reduction: CrystalClear (Rigaku/MSC, 2002); program(s) used to solve structure: SHELXS97 (Sheldrick, 2008); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008); molecular graphics: ORTEP-3 for Windows (Farrugia, 1997); software used to prepare material for publication: WinGX (Farrugia, 1999).[U(C14H8O5)O2(H2O)] | F(000) = 1000 |
Mr = 544.25 | Dx = 2.505 Mg m−3 |
Monoclinic, P21/c | Mo Kα radiation, λ = 0.71073 Å |
Hall symbol: -P 2ybc | Cell parameters from 4425 reflections |
a = 16.0160 (6) Å | θ = 2.5–25.0° |
b = 8.8832 (3) Å | µ = 11.29 mm−1 |
c = 10.1952 (4) Å | T = 296 K |
β = 95.736 (1)° | Block, yellow |
V = 1443.24 (9) Å3 | 0.19 × 0.18 × 0.17 mm |
Z = 4 |
Rigaku R-AXIS RAPID diffractometer | 3606 independent reflections |
Radiation source: fine-focus sealed tube | 3188 reflections with I > 2σ(I) |
Graphite monochromator | Rint = 0.020 |
ω scan | θmax = 28.4°, θmin = 1.3° |
Absorption correction: multi-scan (ABSCOR; Higashi, 1995) | h = −21→20 |
Tmin = 0.135, Tmax = 0.147 | k = −11→11 |
10376 measured reflections | l = −13→11 |
Refinement on F2 | Primary atom site location: structure-invariant direct methods |
Least-squares matrix: full | Secondary atom site location: difference Fourier map |
R[F2 > 2σ(F2)] = 0.019 | Hydrogen site location: inferred from neighbouring sites |
wR(F2) = 0.064 | H-atom parameters constrained |
S = 1.17 | w = 1/[σ2(Fo2) + (0.0365P)2] where P = (Fo2 + 2Fc2)/3 |
3606 reflections | (Δ/σ)max = 0.002 |
208 parameters | Δρmax = 0.74 e Å−3 |
0 restraints | Δρmin = −0.88 e Å−3 |
[U(C14H8O5)O2(H2O)] | V = 1443.24 (9) Å3 |
Mr = 544.25 | Z = 4 |
Monoclinic, P21/c | Mo Kα radiation |
a = 16.0160 (6) Å | µ = 11.29 mm−1 |
b = 8.8832 (3) Å | T = 296 K |
c = 10.1952 (4) Å | 0.19 × 0.18 × 0.17 mm |
β = 95.736 (1)° |
Rigaku R-AXIS RAPID diffractometer | 3606 independent reflections |
Absorption correction: multi-scan (ABSCOR; Higashi, 1995) | 3188 reflections with I > 2σ(I) |
Tmin = 0.135, Tmax = 0.147 | Rint = 0.020 |
10376 measured reflections |
R[F2 > 2σ(F2)] = 0.019 | 0 restraints |
wR(F2) = 0.064 | H-atom parameters constrained |
S = 1.17 | Δρmax = 0.74 e Å−3 |
3606 reflections | Δρmin = −0.88 e Å−3 |
208 parameters |
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. |
x | y | z | Uiso*/Ueq | ||
U1 | 0.586399 (8) | 0.547362 (15) | 0.296990 (13) | 0.02255 (6) | |
O1 | 0.55538 (19) | 0.4926 (4) | 0.6780 (3) | 0.0334 (6) | |
O4 | 1.2633 (2) | 0.4586 (4) | 0.6570 (3) | 0.0393 (8) | |
O5 | 1.31269 (18) | 0.3423 (4) | 0.8388 (3) | 0.0366 (7) | |
C14 | 1.2507 (3) | 0.3891 (5) | 0.7634 (4) | 0.0287 (8) | |
C11 | 1.1633 (2) | 0.3682 (4) | 0.7976 (4) | 0.0259 (8) | |
C12 | 1.0998 (3) | 0.4558 (4) | 0.7347 (4) | 0.0293 (9) | |
H12 | 1.1117 | 0.5218 | 0.6683 | 0.035* | |
C10 | 1.1455 (3) | 0.2688 (5) | 0.8968 (4) | 0.0303 (8) | |
H10 | 1.1882 | 0.2115 | 0.9408 | 0.036* | |
C13 | 1.0187 (3) | 0.4458 (4) | 0.7699 (4) | 0.0316 (9) | |
H13 | 0.9765 | 0.5067 | 0.7294 | 0.038* | |
C9 | 1.0644 (2) | 0.2558 (5) | 0.9295 (4) | 0.0308 (8) | |
H9 | 1.0521 | 0.1877 | 0.9941 | 0.037* | |
C8 | 1.0012 (2) | 0.3435 (5) | 0.8665 (4) | 0.0269 (8) | |
C1 | 0.6145 (3) | 0.4466 (4) | 0.6168 (4) | 0.0251 (8) | |
C2 | 0.6980 (2) | 0.4239 (4) | 0.6891 (4) | 0.0243 (8) | |
C7 | 0.7623 (2) | 0.3572 (5) | 0.6279 (4) | 0.0279 (8) | |
H7 | 0.7535 | 0.3328 | 0.5389 | 0.033* | |
C6 | 0.8389 (3) | 0.3266 (5) | 0.6969 (4) | 0.0304 (9) | |
H6 | 0.8814 | 0.2807 | 0.6555 | 0.037* | |
C5 | 0.8514 (2) | 0.3659 (5) | 0.8298 (4) | 0.0273 (8) | |
C4 | 0.7882 (3) | 0.4337 (5) | 0.8920 (4) | 0.0321 (9) | |
H4 | 0.7974 | 0.4596 | 0.9806 | 0.038* | |
C3 | 0.7115 (3) | 0.4629 (4) | 0.8222 (4) | 0.0307 (9) | |
H3 | 0.6690 | 0.5084 | 0.8638 | 0.037* | |
O3 | 0.92367 (17) | 0.3279 (4) | 0.9105 (3) | 0.0370 (7) | |
O2 | 0.60500 (19) | 0.4162 (4) | 0.4939 (3) | 0.0345 (7) | |
O7 | 0.5825 (2) | 0.7188 (3) | 0.3837 (3) | 0.0359 (7) | |
O6 | 0.58900 (19) | 0.3749 (3) | 0.2127 (3) | 0.0350 (7) | |
O8 | 0.50947 (19) | 0.6486 (3) | 0.0952 (3) | 0.0369 (7) | |
H11 | 0.4613 | 0.6883 | 0.0787 | 0.055* | |
H8 | 0.5375 | 0.6547 | 0.0288 | 0.055* |
U11 | U22 | U33 | U12 | U13 | U23 | |
U1 | 0.01670 (9) | 0.02981 (9) | 0.02128 (9) | 0.00041 (5) | 0.00266 (6) | −0.00035 (5) |
O1 | 0.0196 (15) | 0.0439 (16) | 0.0374 (17) | 0.0045 (13) | 0.0064 (12) | 0.0048 (14) |
O4 | 0.0205 (16) | 0.066 (2) | 0.0309 (16) | −0.0022 (14) | 0.0011 (12) | 0.0114 (14) |
O5 | 0.0197 (14) | 0.0566 (19) | 0.0330 (15) | −0.0005 (14) | 0.0010 (12) | 0.0132 (14) |
C14 | 0.022 (2) | 0.037 (2) | 0.0282 (19) | −0.0036 (17) | 0.0037 (15) | −0.0004 (17) |
C11 | 0.0195 (18) | 0.032 (2) | 0.0260 (18) | −0.0040 (16) | 0.0004 (14) | −0.0040 (16) |
C12 | 0.023 (2) | 0.036 (2) | 0.029 (2) | −0.0037 (16) | 0.0002 (16) | 0.0052 (16) |
C10 | 0.023 (2) | 0.035 (2) | 0.031 (2) | 0.0035 (17) | −0.0028 (15) | 0.0052 (17) |
C13 | 0.022 (2) | 0.038 (2) | 0.035 (2) | 0.0007 (16) | −0.0016 (17) | 0.0073 (17) |
C9 | 0.022 (2) | 0.038 (2) | 0.032 (2) | −0.0036 (17) | 0.0006 (15) | 0.0086 (17) |
C8 | 0.0161 (18) | 0.040 (2) | 0.0235 (18) | −0.0034 (16) | −0.0017 (14) | −0.0002 (16) |
C1 | 0.0184 (19) | 0.0268 (19) | 0.030 (2) | −0.0022 (14) | 0.0024 (15) | 0.0066 (15) |
C2 | 0.0156 (18) | 0.0284 (19) | 0.029 (2) | −0.0013 (14) | 0.0012 (15) | 0.0050 (15) |
C7 | 0.024 (2) | 0.036 (2) | 0.0233 (18) | 0.0026 (17) | 0.0018 (15) | −0.0009 (16) |
C6 | 0.0204 (19) | 0.044 (2) | 0.027 (2) | 0.0069 (17) | 0.0026 (15) | −0.0029 (17) |
C5 | 0.0165 (18) | 0.038 (2) | 0.0270 (18) | −0.0005 (16) | −0.0020 (14) | 0.0056 (16) |
C4 | 0.025 (2) | 0.044 (2) | 0.026 (2) | −0.0015 (18) | −0.0005 (16) | −0.0021 (17) |
C3 | 0.023 (2) | 0.040 (2) | 0.030 (2) | 0.0051 (16) | 0.0025 (17) | −0.0051 (16) |
O3 | 0.0169 (14) | 0.066 (2) | 0.0278 (14) | 0.0009 (14) | −0.0014 (11) | 0.0103 (14) |
O2 | 0.0238 (16) | 0.0517 (17) | 0.0270 (15) | 0.0005 (13) | −0.0015 (12) | 0.0113 (13) |
O7 | 0.0363 (17) | 0.0354 (16) | 0.0362 (16) | 0.0002 (13) | 0.0045 (13) | −0.0099 (13) |
O6 | 0.0298 (16) | 0.0351 (16) | 0.0399 (17) | 0.0026 (13) | 0.0024 (12) | −0.0072 (13) |
O8 | 0.0334 (17) | 0.0473 (17) | 0.0298 (15) | 0.0056 (14) | 0.0027 (12) | 0.0101 (13) |
U1—O1i | 2.337 (3) | C10—H10 | 0.9300 |
U1—O2 | 2.315 (3) | C13—C8 | 1.389 (6) |
U1—O4ii | 2.407 (3) | C13—H13 | 0.9300 |
U1—O5ii | 2.437 (3) | C9—C8 | 1.384 (5) |
U1—O6 | 1.759 (3) | C9—H9 | 0.9300 |
U1—O7 | 1.765 (3) | C8—O3 | 1.369 (5) |
U1—O8 | 2.461 (3) | C1—O2 | 1.275 (5) |
U1—C14ii | 2.798 (4) | C1—C2 | 1.475 (5) |
O1—C1 | 1.254 (5) | C2—C7 | 1.389 (5) |
O1—U1i | 2.337 (3) | C2—C3 | 1.396 (6) |
O4—C14 | 1.282 (5) | C7—C6 | 1.379 (5) |
O4—U1ii | 2.407 (3) | C7—H7 | 0.9300 |
O5—C14 | 1.263 (5) | C6—C5 | 1.395 (5) |
O5—U1ii | 2.437 (3) | C6—H6 | 0.9300 |
C14—C11 | 1.488 (5) | C5—C4 | 1.385 (6) |
C14—U1ii | 2.798 (4) | C5—O3 | 1.393 (4) |
C11—C12 | 1.386 (6) | C4—C3 | 1.381 (6) |
C11—C10 | 1.393 (5) | C4—H4 | 0.9300 |
C12—C13 | 1.384 (6) | C3—H3 | 0.9300 |
C12—H12 | 0.9300 | O8—H11 | 0.8499 |
C10—C9 | 1.377 (6) | O8—H8 | 0.8500 |
O6—U1—O7 | 178.90 (14) | C13—C12—H12 | 119.7 |
O6—U1—O2 | 88.75 (12) | C11—C12—H12 | 119.7 |
O7—U1—O2 | 90.45 (12) | C9—C10—C11 | 119.6 (4) |
O6—U1—O1i | 89.53 (13) | C9—C10—H10 | 120.2 |
O7—U1—O1i | 89.62 (13) | C11—C10—H10 | 120.2 |
O2—U1—O1i | 82.59 (10) | C12—C13—C8 | 119.2 (4) |
O6—U1—O4ii | 90.22 (13) | C12—C13—H13 | 120.4 |
O7—U1—O4ii | 90.34 (13) | C8—C13—H13 | 120.4 |
O2—U1—O4ii | 77.30 (10) | C10—C9—C8 | 120.3 (4) |
O1i—U1—O4ii | 159.90 (11) | C10—C9—H9 | 119.8 |
O6—U1—O5ii | 91.33 (12) | C8—C9—H9 | 119.8 |
O7—U1—O5ii | 89.77 (13) | O3—C8—C9 | 115.9 (3) |
O2—U1—O5ii | 131.32 (10) | O3—C8—C13 | 123.5 (4) |
O1i—U1—O5ii | 146.09 (10) | C9—C8—C13 | 120.5 (4) |
O4ii—U1—O5ii | 54.01 (10) | O1—C1—O2 | 122.4 (4) |
O6—U1—O8 | 86.79 (12) | O1—C1—C2 | 119.2 (4) |
O7—U1—O8 | 93.66 (12) | O2—C1—C2 | 118.4 (4) |
O2—U1—O8 | 156.87 (10) | C7—C2—C3 | 119.5 (4) |
O1i—U1—O8 | 74.70 (10) | C7—C2—C1 | 120.6 (4) |
O4ii—U1—O8 | 125.36 (10) | C3—C2—C1 | 119.8 (4) |
O5ii—U1—O8 | 71.51 (10) | C6—C7—C2 | 121.1 (4) |
O6—U1—C14ii | 90.00 (13) | C6—C7—H7 | 119.4 |
O7—U1—C14ii | 90.93 (13) | C2—C7—H7 | 119.4 |
O2—U1—C14ii | 104.52 (11) | C7—C6—C5 | 118.7 (4) |
O1i—U1—C14ii | 172.86 (11) | C7—C6—H6 | 120.6 |
O4ii—U1—C14ii | 27.22 (11) | C5—C6—H6 | 120.6 |
O5ii—U1—C14ii | 26.82 (10) | C4—C5—O3 | 116.0 (3) |
O8—U1—C14ii | 98.17 (11) | C4—C5—C6 | 120.9 (4) |
C1—O1—U1i | 142.7 (3) | O3—C5—C6 | 122.9 (4) |
C14—O4—U1ii | 93.6 (2) | C3—C4—C5 | 119.9 (4) |
C14—O5—U1ii | 92.7 (2) | C3—C4—H4 | 120.0 |
O5—C14—O4 | 119.6 (4) | C5—C4—H4 | 120.0 |
O5—C14—C11 | 121.1 (3) | C4—C3—C2 | 119.9 (4) |
O4—C14—C11 | 119.3 (4) | C4—C3—H3 | 120.1 |
O5—C14—U1ii | 60.5 (2) | C2—C3—H3 | 120.1 |
O4—C14—U1ii | 59.2 (2) | C8—O3—C5 | 120.7 (3) |
C11—C14—U1ii | 175.5 (3) | C1—O2—U1 | 137.5 (3) |
C12—C11—C10 | 119.9 (4) | U1—O8—H11 | 133.3 |
C12—C11—C14 | 119.1 (4) | U1—O8—H8 | 115.4 |
C10—C11—C14 | 121.0 (4) | H11—O8—H8 | 110.9 |
C13—C12—C11 | 120.5 (4) |
Symmetry codes: (i) −x+1, −y+1, −z+1; (ii) −x+2, −y+1, −z+1. |
D—H···A | D—H | H···A | D···A | D—H···A |
O8—H8···O7iii | 0.85 | 2.05 | 2.812 (4) | 150 |
O8—H11···O2iv | 0.85 | 2.37 | 3.083 (4) | 142 |
Symmetry codes: (iii) x, −y+3/2, z−1/2; (iv) −x+1, y+1/2, −z+1/2. |
Experimental details
Crystal data | |
Chemical formula | [U(C14H8O5)O2(H2O)] |
Mr | 544.25 |
Crystal system, space group | Monoclinic, P21/c |
Temperature (K) | 296 |
a, b, c (Å) | 16.0160 (6), 8.8832 (3), 10.1952 (4) |
β (°) | 95.736 (1) |
V (Å3) | 1443.24 (9) |
Z | 4 |
Radiation type | Mo Kα |
µ (mm−1) | 11.29 |
Crystal size (mm) | 0.19 × 0.18 × 0.17 |
Data collection | |
Diffractometer | Rigaku R-AXIS RAPID diffractometer |
Absorption correction | Multi-scan (ABSCOR; Higashi, 1995) |
Tmin, Tmax | 0.135, 0.147 |
No. of measured, independent and observed [I > 2σ(I)] reflections | 10376, 3606, 3188 |
Rint | 0.020 |
(sin θ/λ)max (Å−1) | 0.668 |
Refinement | |
R[F2 > 2σ(F2)], wR(F2), S | 0.019, 0.064, 1.17 |
No. of reflections | 3606 |
No. of parameters | 208 |
H-atom treatment | H-atom parameters constrained |
Δρmax, Δρmin (e Å−3) | 0.74, −0.88 |
Computer programs: RAPID-AUTO (Rigaku, 1998), CrystalClear (Rigaku/MSC, 2002), SHELXS97 (Sheldrick, 2008), SHELXL97 (Sheldrick, 2008), ORTEP-3 for Windows (Farrugia, 1997), WinGX (Farrugia, 1999).
U1—O1i | 2.337 (3) | U1—O6 | 1.759 (3) |
U1—O2 | 2.315 (3) | U1—O7 | 1.765 (3) |
U1—O4ii | 2.407 (3) | U1—O8 | 2.461 (3) |
U1—O5ii | 2.437 (3) |
Symmetry codes: (i) −x+1, −y+1, −z+1; (ii) −x+2, −y+1, −z+1. |
D—H···A | D—H | H···A | D···A | D—H···A |
O8—H8···O7iii | 0.85 | 2.05 | 2.812 (4) | 149.7 |
O8—H11···O2iv | 0.85 | 2.37 | 3.083 (4) | 141.8 |
Symmetry codes: (iii) x, −y+3/2, z−1/2; (iv) −x+1, y+1/2, −z+1/2. |
Acknowledgements
We gratefully acknowledge the financial support of the National Natural Science Foundation of China (No. 50573030).
References
Cahill, C. L., de Lilla, D. T. & Frisch, M. (2007). CrystEngComm, 9, 15–26. Web of Science CSD CrossRef CAS Google Scholar
Farrugia, L. J. (1997). J. Appl. Cryst. 30, 565. CrossRef IUCr Journals Google Scholar
Farrugia, L. J. (1999). J. Appl. Cryst. 32, 837–838. CrossRef CAS IUCr Journals Google Scholar
Higashi, T. (1995). ABSCOR. Rigaku Corporation, Tokyo, Japan. Google Scholar
Masci, B. & Thuéry, P. (2008). CrystEngComm, 10, 1082–1087. Web of Science CSD CrossRef CAS Google Scholar
Rigaku (1998). PROCESS-AUTO. Rigaku Corporation, Tokyo, Japan. Google Scholar
Rigaku/MSC (2002). CrystalClear. Rigaku/MSC, The Woodlands, Texas, USA. Google Scholar
Sheldrick, G. M. (2008). Acta Cryst. A64, 112–122. Web of Science CrossRef CAS IUCr Journals Google Scholar
Thuéry, P. & Masci, B. (2008). Cryst. Growth Des. 8, 3430–3436. Google Scholar
Yu, Z.-T., Liao, Z.-L., Jiang, Y.-S., Li, G.-D. & Chen, J.-S. (2004). Chem. Commun. pp. 1814–1815. Web of Science CSD CrossRef Google Scholar
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Recently the design and synthesis of porous uranyl-organic frameworks (UOFs) have received rather considerable attention due to their potential applications (Thuéry & Masci, 2008; Cahill et al., 2007; Masci & Thuéry, 2008; Yu et al., 2004; Chen et al., 2003). However the coordination polymers of uranyl with 4,4'-oxydibenzoate ligand (oba) have not been reported to our knowledge. We are currently interested in using oba as a bridging ligand to build novel UOFs. Herein we report a novel UOF of [UO2(oba)(H2O)]n.
The compound possesses a 1-D double chain architecture, in which the asymmetric unit consists of one UO22+ cation, one oxy-bis(benzoate) anion and one coordinated water molecule. The central U atom is seven-coordinated in a UO7 pentagonal-bipyramidal geometry by four O atoms from three different oba2- ligands and one water O atom, and other two O atoms are oxo groups in axial positions (Fig. 1). The coordinate bond distances are listed in Table 1, which are comparable to the related uranyl carboxylate compound (Yu et al., 2004). The terminal groups of the oba ligand coordinate to three U centers to form the 1D double chain framework (Fig. 2). The O—H···O hydrogen bonding links the polymeric chains into 3D supramolecular structure (Table 2 and Fig. 3).