supplementary materials


hg5272 scheme

Acta Cryst. (2013). E69, m52    [ doi:10.1107/S160053681205026X ]

Poly[[tetraaquadi-[mu]4-fumarato-[mu]2-oxalato-dierbium(III)] tetrahydrate]

Q.-F. Yang, X.-Z. Wang and P. Xue

Abstract top

The title compound, {[Er2(C4H2O4)2(C2O4)(H2O)4]·4H2O}n, was synthesized by the reaction of erbium nitrate hexahydrate with fumaric acid and oxalic acid under hydrothermal conditions. The Er3+ cation (site symmetry ..2) is eight-coordinated by six O atoms from four fumarate anions (site symmetry ..2) and one bidentate oxalate anion (site symmetry 222), and by two water molecules. The complex exhibits a three-dimensional structure consisting of oxalate pillared Er-fumarate layers with channels occupied by coordinating and lattice water molecules. The three-dimensional structure features by Owater-H...O hydrogen bonds involving both the coordinating and lattice water molecules.

Comment top

In recent years, lanthanide metal-organic compounds have been of great interest due to their fascinating structures and potential applications in magnetism, luminescence, catalysis, gas storage and separation. Multitopic carboxylates have received considerable study due to their availability and potential for allowing for the tailored design of such frameworks. As we know, fumaric acid is a unique ligand with a relatively small, conjugated middle part and versatile coordination modes. A large number of lanthanide metal complexes containing fumarate ligands have been reported, see: Zhang et al. (2006). And lanthanide-containing MOFs with two different flexible carboxylate ligands are less developed, see: Zhang et al.(2008); Zhu et al.(2007). In this paper, we report the synthesis and structure of a new metal-organic compound constructed from fumarate ligands coordinated to Er atoms in the presence of oxalate ligands.

In the title compound I, Er1 is eight-coordinated with four O atoms from four fumarate ligands (O2iii, O1iv, O2, O1v, (iii), 1.25 - x, 0.25 - y, z; (iv) 1.5 - x, 0.5 - y, 1 - z; (v) -0.25 + x, -0.25 + y, 1 - z), two O atoms from one oxalate ligand (O3 and O3iii) and two water molecules (O4 and O4iii) (Fig. 1). The Er—O bond lengths are between 2.273 (3)–2.428 (3) Å. The Er atoms are linked through bridging carboxyl groups of fumarate ligands to form two-dimensional Er–fum layers in the ab plane (Fig. 2). Along the c direction, the Er-fum layers are pillared by the oxalic acid resulting in a three-dimensional structure. The framework contains approximately 6.2 Å×11.1 Å rectangular channels along the [100] direction. These channels are occupied by coordinated and free water molecules (Fig. 3). The three-dimensional structure is stabilized by Owater—H···O hydrogen bonds involving both the coordinated and free water molecules.

Related literature top

For lanthanide–metal complexes containing fumarate ligands, see: Zhang et al. (2006). For lanthanide-containing structures with metal-organic frameworks and two different flexible carboxylate ligands, see: Zhang et al. (2008); Zhu et al. (2007).

Experimental top

A mixture of fumaric acid (0.058 g, 0.50 mmol), oxalic acid (0.063 g, 0.50 mmol) and erbium nitrate hexahydrate (0.230 g, 0.50 mmol) in distilled water (15 ml) was stirred fully in air, and then sealed in 25 ml Teflon-lined stainless steel container, which was heated firstly at 403 K for 2 days and then at 443 K for 1 day. The pink block product, I, was crystallized upon cooling to 273 K.

Refinement top

The H atoms attached to carbon were positioned geometrically and treated as riding on their parent atoms, with C—H 0.93. The hydrogen atoms of the water molecules were located in difference maps and refined by using the 'DFIX' command with O—H = 0.85 (2)Å with Uiso(H) = 1.5Uiso(O).

Computing details top

Data collection: SMART (Bruker, 2007); cell refinement: SAINT (Bruker, 2007); data reduction: SAINT (Bruker, 2007); program(s) used to solve structure: SHELXS97 (Sheldrick, 2008); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008); molecular graphics: DIAMOND (Brandenburg, 1999); software used to prepare material for publication: SHELXTL (Sheldrick, 2008).

Figures top
[Figure 1] Fig. 1. Coordination environment of Er1 in compound I with labelling and displacement ellipsoids drawn at the 30% probability level. Symmetry codes: (i) 2.25 - x, 0.25 - y, z; (ii) 1.25 - x, y, 1.25 - z; (iii) 1.25 - x, 0.25 - y, z; (iv) 1.5 - x, 0.5 - y, 1 - z; (v) -0.25 + x, -0.25 + y, 1 - z; (vi) 1 + x, y, z; (vii) 2 - x, -y, 1 - z; (viii) x, 0.25 - y, 1.25 - z; (ix) -1 + x, y, z; (x) -0.75 + x, 0.25 + y, 1 - z.
[Figure 2] Fig. 2. The two-dimensional Er-fum layer extends in the ab plane.
[Figure 3] Fig. 3. The three-dimensional network with rectangular channels along the [100] direction.
Poly[[tetraaquadi-µ4-fumarato-µ2-oxalato-dierbium(III)] tetrahydrate] top
Crystal data top
[Er2(C4H2O4)2(C2O4)(H2O)4]·4H2ODx = 2.621 Mg m3
Mr = 794.78Melting point: not measured K
Orthorhombic, FdddMo Kα radiation, λ = 0.71073 Å
Hall symbol: -F 2uv 2vwCell parameters from 9875 reflections
a = 9.6016 (19) Åθ = 3.0–27.5°
b = 15.701 (3) ŵ = 8.38 mm1
c = 26.722 (5) ÅT = 293 K
V = 4028.5 (14) Å3Block, pink
Z = 80.19 × 0.16 × 0.13 mm
F(000) = 3008
Data collection top
Bruker SMART APEX CCD
diffractometer
1162 independent reflections
Radiation source: fine-focus sealed tube1088 reflections with I > 2σ(I)
Graphite monochromatorRint = 0.022
Detector resolution: 9.00cm pixels mm-1θmax = 27.5°, θmin = 3.0°
ω scansh = 1212
Absorption correction: multi-scan
(SADABS; Bruker, 2001)
k = 2020
Tmin = 0.305, Tmax = 0.402l = 3431
9284 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)] = 0.018Hydrogen site location: inferred from neighbouring sites
wR(F2) = 0.045H-atom parameters constrained
S = 1.11 w = 1/[σ2(Fo2) + (0.0186P)2 + 60.2587P]
where P = (Fo2 + 2Fc2)/3
1162 reflections(Δ/σ)max = 0.003
74 parametersΔρmax = 0.51 e Å3
0 restraintsΔρmin = 1.04 e Å3
Crystal data top
[Er2(C4H2O4)2(C2O4)(H2O)4]·4H2OV = 4028.5 (14) Å3
Mr = 794.78Z = 8
Orthorhombic, FdddMo Kα radiation
a = 9.6016 (19) ŵ = 8.38 mm1
b = 15.701 (3) ÅT = 293 K
c = 26.722 (5) Å0.19 × 0.16 × 0.13 mm
Data collection top
Bruker SMART APEX CCD
diffractometer
1162 independent reflections
Absorption correction: multi-scan
(SADABS; Bruker, 2001)
1088 reflections with I > 2σ(I)
Tmin = 0.305, Tmax = 0.402Rint = 0.022
9284 measured reflectionsθmax = 27.5°
Refinement top
R[F2 > 2σ(F2)] = 0.018 w = 1/[σ2(Fo2) + (0.0186P)2 + 60.2587P]
where P = (Fo2 + 2Fc2)/3
wR(F2) = 0.045Δρmax = 0.51 e Å3
S = 1.11Δρmin = 1.04 e Å3
1162 reflectionsAbsolute structure: ?
74 parametersFlack parameter: ?
0 restraintsRogers parameter: ?
H-atom parameters constrained
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
C10.9358 (4)0.1660 (2)0.52974 (13)0.0167 (6)
C21.0906 (4)0.1604 (3)0.53278 (16)0.0268 (8)
H21.14070.21100.53480.032*
C30.62500.0756 (3)0.62500.0150 (8)
Er10.62500.12500.508677 (7)0.01528 (8)
O10.8868 (3)0.23742 (16)0.51740 (10)0.0237 (5)
O20.8597 (3)0.10210 (16)0.53731 (11)0.0239 (5)
O30.6164 (3)0.04009 (15)0.58332 (9)0.0190 (5)
O40.4757 (3)0.12267 (15)0.43533 (9)0.0256 (5)
H4A0.39850.14470.44400.031*
H4B0.45950.07060.42880.031*
O50.5533 (3)0.20049 (15)0.34370 (9)0.0859 (16)
H5A0.52980.17690.37110.103*
H5B0.56610.25340.34850.129*
Atomic displacement parameters (Å2) top
U11U22U33U12U13U23
C10.0141 (15)0.0186 (16)0.0173 (16)0.0032 (13)0.0010 (13)0.0001 (13)
C20.0159 (17)0.0232 (18)0.041 (2)0.0021 (14)0.0015 (15)0.0025 (17)
C30.0133 (19)0.013 (2)0.019 (2)0.0000.0012 (19)0.000
Er10.01765 (12)0.01422 (11)0.01396 (11)0.00560 (8)0.0000.000
O10.0239 (13)0.0200 (12)0.0270 (13)0.0067 (10)0.0003 (11)0.0045 (10)
O20.0168 (12)0.0205 (12)0.0344 (14)0.0009 (10)0.0001 (11)0.0027 (11)
O30.0269 (13)0.0139 (11)0.0161 (11)0.0003 (10)0.0015 (10)0.0010 (9)
O40.0296 (13)0.0215 (12)0.0256 (13)0.0017 (11)0.0040 (11)0.0002 (11)
O50.099 (4)0.076 (3)0.082 (3)0.011 (3)0.012 (3)0.037 (3)
Geometric parameters (Å, º) top
C1—O21.258 (4)Er1—O32.401 (2)
C1—O11.260 (4)Er1—O22.407 (3)
C1—C21.491 (5)Er1—O2iii2.407 (3)
C2—C2i1.294 (8)Er1—O42.428 (2)
C2—H20.9300Er1—O4iii2.428 (2)
C3—O31.249 (3)O1—Er1iv2.273 (3)
C3—O3ii1.249 (3)O4—H4A0.8500
C3—C3iii1.550 (9)O4—H4B0.8499
Er1—O1iv2.273 (3)O5—H5A0.8500
Er1—O1v2.273 (3)O5—H5B0.8500
Er1—O3iii2.401 (2)
O2—C1—O1122.4 (3)O3—Er1—O2iii77.67 (9)
O2—C1—C2121.5 (3)O2—Er1—O2iii142.93 (13)
O1—C1—C2116.0 (3)O1iv—Er1—O474.78 (9)
C2i—C2—C1124.0 (5)O1v—Er1—O476.55 (9)
C2i—C2—H2118.0O3iii—Er1—O4134.38 (9)
C1—C2—H2118.0O3—Er1—O4129.93 (8)
O3—C3—O3ii126.9 (4)O2—Er1—O4143.80 (9)
O3—C3—C3iii116.6 (2)O2iii—Er1—O472.91 (9)
O3ii—C3—C3iii116.6 (2)O1iv—Er1—O4iii76.55 (9)
O1iv—Er1—O1v144.28 (13)O1v—Er1—O4iii74.78 (9)
O1iv—Er1—O3iii74.25 (9)O3iii—Er1—O4iii129.93 (8)
O1v—Er1—O3iii141.35 (9)O3—Er1—O4iii134.38 (9)
O1iv—Er1—O3141.35 (9)O2—Er1—O4iii72.91 (9)
O1v—Er1—O374.25 (9)O2iii—Er1—O4iii143.80 (9)
O3iii—Er1—O367.62 (11)O4—Er1—O4iii72.38 (12)
O1iv—Er1—O2106.62 (9)C1—O1—Er1iv160.8 (3)
O1v—Er1—O284.78 (9)C1—O2—Er1111.9 (2)
O3iii—Er1—O277.67 (9)C3—O3—Er1119.4 (2)
O3—Er1—O271.66 (9)Er1—O4—H4A106.7
O1iv—Er1—O2iii84.78 (9)Er1—O4—H4B106.7
O1v—Er1—O2iii106.62 (9)H4A—O4—H4B106.7
O3iii—Er1—O2iii71.66 (9)H5A—O5—H5B109.5
Symmetry codes: (i) x+9/4, y+1/4, z; (ii) x+5/4, y, z+5/4; (iii) x+5/4, y+1/4, z; (iv) x+3/2, y+1/2, z+1; (v) x1/4, y1/4, z+1.
Hydrogen-bond geometry (Å, º) top
D—H···AD—HH···AD···AD—H···A
O4—H4A···O5vi0.852.353.045 (5)139
O4—H4B···O3vii0.851.912.750 (3)168
O5—H5A···O40.851.992.836180
O5—H5B···O2viii0.852.362.938 (4)125
Symmetry codes: (vi) x+3/4, y, z+3/4; (vii) x+1, y, z+1; (viii) x+3/2, y+1/4, z1/4.
Hydrogen-bond geometry (Å, º) top
D—H···AD—HH···AD···AD—H···A
O4—H4A···O5i0.852.353.045 (5)138.8
O4—H4B···O3ii0.851.912.750 (3)168.1
O5—H5A···O40.851.992.836179.5
O5—H5B···O2iii0.852.362.938 (4)125.4
Symmetry codes: (i) x+3/4, y, z+3/4; (ii) x+1, y, z+1; (iii) x+3/2, y+1/4, z1/4.
Acknowledgements top

This work was supported by the Natural Science Foundation of Ningxia Hui Autonomous Region (No. NZ1150).

references
References top

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