Poly[tetra­aqua­(5-hy­droxy­pyridin-1-ium-3-carboxyl­ato-κO³)tris­(μ-oxalato-κ⁴O¹,O²:O^1′,O^2′)dieuropium(III)]

In the title compound, [Eu₂(C₆H₅NO₃)₂(C₂O₄)₃(H₂O)₄]_n, the Eu^III atom is bonded to one O atom from a monodentate 5-hy­droxy­pyridin-1-ium-3-carboxyl­ate ligand, six O atoms from three oxalate ligands and two water mol­ecules, exhibiting a highly distorted tricapped trigonal geometry. Three independent oxalate ligands, each lying on an inversion center, bridge the Eu^III atoms, forming a brickwall-like layer parallel to (001), which is stabilized by intra­layer O—H...O hydrogen bonds. The layers are further linked through inter­layer O—H...O and N—H...O hydrogen bonds and π–π inter­actions between the pyridine rings [centroid–centroid distance = 3.5741 (14) Å] into a three-dimensional supra­molecular network.

Key indicators

• Single-crystal X-ray study
• T = 153 K
• Mean [sigma](C-C) = 0.003 Å
• R factor = 0.018
• wR factor = 0.038
• Data-to-parameter ratio = 14.2

checkCIF/PLATON results

No syntax errors found



Alert level C
PLAT250_ALERT_2_C Large U3/U1 Ratio for Average U(i,j) Tensor ....        2.1
PLAT910_ALERT_3_C Missing # of FCF Reflections Below Th(Min) .....          1
PLAT975_ALERT_2_C Positive Residual Density at 0.92A from O10    .       0.45 eA-3
PLAT976_ALERT_2_C Negative Residual Density at 0.96A from N1     .      -0.42 eA-3

Alert level G
PLAT004_ALERT_5_G Info: Polymeric Structure Found with Dimension .          2
PLAT005_ALERT_5_G No _iucr_refine_instructions_details  in the CIF          ?
PLAT007_ALERT_5_G Note: Number of Unrefined D-H Atoms ............          1
PLAT042_ALERT_1_G Calc. and Reported MoietyFormula Strings  Differ          ?
PLAT045_ALERT_1_G Calculated and Reported Z Differ by ............       2.00 Ratio
PLAT154_ALERT_1_G The su's on the Cell Angles are Equal ..........    0.00300 Deg.
PLAT232_ALERT_2_G Hirshfeld Test Diff (M-X)  Eu1    --  O4      ..        5.6 su
PLAT764_ALERT_4_G Overcomplete CIF Bond List Detected (Rep/Expd) .       1.11 Ratio
PLAT912_ALERT_4_G Missing # of FCF Reflections Above STh/L=  0.600        312

   0 ALERT level A = Most likely a serious problem - resolve or explain
   0 ALERT level B = A potentially serious problem, consider carefully
   4 ALERT level C = Check. Ensure it is not caused by an omission or oversight
   9 ALERT level G = General information/check it is not something unexpected

   3 ALERT type 1 CIF construction/syntax error, inconsistent or missing data
   4 ALERT type 2 Indicator that the structure model may be wrong or deficient
   1 ALERT type 3 Indicator that the structure quality may be low
   2 ALERT type 4 Improvement, methodology, query or suggestion
   3 ALERT type 5 Informative message, check

---

S1. Comment

Pyridine-carboxylic derivatives are of resent interest in coordination polymers due to their structural diverity and unique physical properties (Black et al., 2009; Cañadillas-Delgado et al., 2010). Some transition and/or rare earth metal complexes with pyridine-2,5/6-dicarboxylic acid (Sun et al., 2010; Wen et al., 2007) or 2/6-hydroxynicotinic acid (Hu et al., 2007; Xu et al., 2008) have been prepared and documented. Recently, a few coordination polymers from 5-hydroxynicotinic acid are reported, in which the multidentate bridging ligand exhibits versatile coordination modes in constructing transition metal (Yang et al., 2011) and rare earth metal (Zhang et al., 2012) organic frameworks. The research interest in europium(III) coordination polymers with the ligands comes from their luminescent properties (Decadt et al., 2012; Gai et al., 2012; Ramya et al., 2012) and applications (Bunzli, 2010). Here, we report the crystal structure of an europium(III) complex of a pyridine-carboxylic derivative.

The title compound is isostructural with its Tb(III) and Sm(III) analogues (Zhang et al., 2012). As shown in Fig. 1, the asymmetric unit contains an Eu^III ion, a 3-H-5-hydroxynicotinate ligand, one and half oxalate ligands and two coordinated water molecules. The Eu^III ion is bonded to nine O atoms, one from the 3-H-5-hydroxynicotinate ligand, six from three oxalate ligands and two from the water molecules, exhibiting a highly distorted tricapped trigonal geometry. The Eu^III ions are linked by the oxalate ligands into a brickwall-like layer parallel to (001) (Fig. 2), with Eu···Eu distances of 6.1886 (3), 6.2845 (3) and 6.4206 (3) Å. In the compound, the three oxalate ligands are centrosymmetric and bridge metal ions in a side-by-side coordination manner. The layers are stabilized by intralayer O—H···O hydrogen bonds and further linked through interlayer O—H···O hydrogen bonds and π–π interactions between the pyridine rings [centroid–centroid distance = 3.5741 (14) Å] into a three-dimensional supramolecular network.

Related literature

For background to metal complexes of pyridine-carboxylic derivatives, see: Black et al. (2009); Cañadillas-Delgado et al. (2010); Hu et al. (2007); Sun et al. (2010); Wen et al. (2007); Xu et al. (2008). For structures and properties of coordination polymers with 5-hydroxynicotinic acid, see: Bunzli (2010); Decadt et al. (2012); Gai et al. (2012); Ramya et al. (2012); Yang et al. (2011); Zhang et al. (2012).

S2. Experimental

A mixture of europium nitrate (0.4 mmol, 0.186 g), 5-hydroxynicotinic acid (0.8 mmol, 0.112 g), ammonium oxalate (0.8 mmol, 0.099 g) and 10 ml water was sealed in a 15 ml Teflon-lined autoclave. Colorless crystals suitable for X-ray analysis were obtained by heating the mixture at 443 K for 70 h and then cooled down to room temperature at a rate of 5 K/h (yield: 45%). Analysis, calculated for C₉H₉EuNO₁₁: C 23.54, H 1.98, N 3.05%; found: C 23.36, H 2.02, N 3.01%.

S3. Refinement

C-bound H atoms and H atom on hydroxyl were positioned geometrically and refined as riding atoms, with C—H = 0.93 and O—H = 0.82 Å and with U_iso(H) = 1.2(1.5 for hydroxyl)U_eq(C,O). Other H atoms were located from a difference Fourier map and refined isotropically.

Computing details

Data collection: APEX2 (Bruker, 2007); cell refinement: SAINT (Bruker, 2007); data reduction: SAINT (Bruker, 2007); program(s) used to solve structure: SHELXTL (Sheldrick, 2008); program(s) used to refine structure: SHELXTL (Sheldrick, 2008); molecular graphics: DIAMOND (Brandenburg, 1999); software used to prepare material for publication: SHELXTL (Sheldrick, 2008).

Figures

	Fig. 1. The asymmetric unit of the title compound, showing displacement ellipsoids at the 50% probability level. [Symmetry codes: (i) -x+1, -y+2, -z+1; (ii) -x+2, -y+1, -z+1; (iii) -x+1, -y+1, -z+1.]
	Fig. 2. The layer structure of the title compound parallel to (001). H atoms are omitted for clarity.

Poly[tetraaqua(5-hydroxypyridin-1-ium-3-carboxylato-κO³)tris(µ-oxalato-κ⁴O¹,O²:O^1',O^2')dieuropium(III)]

Crystal data

[Eu2(C6H5NO3)2(C2O4)3(H2O)4]	Z = 1
Mr = 918.26	F(000) = 442
Triclinic, P1	Dx = 2.425 Mg m^−3
Hall symbol: -P 1	Mo Kα radiation, λ = 0.71073 Å
a = 7.5912 (2) Å	Cell parameters from 3135 reflections
b = 8.0973 (3) Å	θ = 2.6–29.4°
c = 10.6706 (3) Å	µ = 5.05 mm^−1
α = 103.493 (3)°	T = 153 K
β = 98.589 (3)°	Block, colorless
γ = 92.240 (3)°	0.24 × 0.17 × 0.08 mm
V = 628.78 (3) Å^3

Data collection

Bruker APEXII CCD diffractometer	3135 independent reflections
Radiation source: fine-focus sealed tube	2965 reflections with I > 2σ(I)
Graphite monochromator	Rint = 0.037
φ and ω scans	θmax = 29.5°, θmin = 2.6°
Absorption correction: multi-scan (SADABS; Sheldrick, 1996)	h = −9→9
Tmin = 0.377, Tmax = 0.688	k = −11→10
12455 measured reflections	l = −13→14

Refinement

Refinement on F^2	Secondary atom site location: difference Fourier map
Least-squares matrix: full	Hydrogen site location: inferred from neighbouring sites
R[F^2 > 2σ(F^2)] = 0.018	H atoms treated by a mixture of independent and constrained refinement
wR(F^2) = 0.038	w = 1/[σ^2(Fo^2) + (0.0087P)^2 + 0.3669P] where P = (Fo^2 + 2Fc^2)/3
S = 1.09	(Δ/σ)max = 0.002
3135 reflections	Δρmax = 0.55 e Å^−3
221 parameters	Δρmin = −0.54 e Å^−3
0 restraints	Extinction correction: SHELXL, Fc^*=kFc[1+0.001xFc^2λ^3/sin(2θ)]^-1/4
Primary atom site location: structure-invariant direct methods	Extinction coefficient: 0.0094 (4)

Special details

Experimental. IR (cm^-1, KBr): 3495(s), 3380(s), 3103(m), 3076(w), 3047(w), 2929(w), 2461(m), 2146(m), 1968(w), 1893(w), 1695(s), 1655(s), 1621(s), 1602(s), 1575(s), 1379(s), 1320(s), 1256(m), 1147(w), 1114(w), 1010(w), 935(w), 880(m), 806(s), 784(s), 667(m), 620(w), 565(w), 531(w), 484(m).

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 (Ų)

	x	y	z	Uiso*/Ueq
C1	0.7687 (3)	0.8846 (3)	0.9610 (2)	0.0095 (5)
C2	0.7420 (3)	0.7295 (3)	1.0146 (2)	0.0094 (5)
C3	0.7733 (3)	0.5691 (3)	0.9454 (2)	0.0116 (5)
H3	0.8082	0.5552	0.8639	0.014*
C4	0.7525 (4)	0.4283 (3)	0.9978 (2)	0.0127 (5)
C5	0.7046 (4)	0.4541 (3)	1.1205 (2)	0.0132 (5)
H5	0.6934	0.3631	1.1590	0.016*
C6	0.6887 (3)	0.7479 (3)	1.1353 (2)	0.0110 (5)
H6	0.6631	0.8540	1.1818	0.013*
C7	0.5536 (3)	1.0035 (3)	0.4431 (2)	0.0099 (5)
C8	1.0255 (3)	0.5479 (3)	0.4489 (2)	0.0084 (5)
C9	0.4854 (3)	0.4971 (3)	0.5697 (2)	0.0101 (5)
Eu1	0.797021 (16)	0.810935 (14)	0.626500 (11)	0.00700 (5)
N1	0.6745 (3)	0.6119 (3)	1.1836 (2)	0.0112 (4)
O1	0.8197 (2)	0.8624 (2)	0.85299 (16)	0.0118 (4)
O2	0.7395 (3)	1.0258 (2)	1.03073 (16)	0.0141 (4)
O3	0.7803 (3)	0.2743 (2)	0.92694 (18)	0.0225 (5)
H3A	0.7713	0.2035	0.9698	0.034*
O4	0.7120 (2)	0.9644 (2)	0.45635 (16)	0.0117 (4)
O5	0.5274 (2)	0.9519 (2)	0.65247 (17)	0.0138 (4)
O6	0.9752 (2)	0.6961 (2)	0.45804 (16)	0.0103 (3)
O7	0.8889 (2)	0.5283 (2)	0.63432 (17)	0.0120 (4)
O8	0.5549 (2)	0.6147 (2)	0.66268 (16)	0.0117 (4)
O9	0.6111 (2)	0.6314 (2)	0.42511 (16)	0.0138 (4)
O10	1.1269 (2)	0.8348 (2)	0.70926 (19)	0.0138 (4)
O11	0.9123 (3)	1.1139 (2)	0.7043 (2)	0.0161 (4)
H1	0.645 (4)	0.622 (4)	1.257 (3)	0.025 (9)*
H7	1.179 (5)	0.876 (4)	0.667 (4)	0.032 (11)*
H8	1.168 (5)	0.893 (4)	0.794 (4)	0.038 (10)*
H9	0.937 (5)	1.181 (5)	0.654 (4)	0.050 (12)*
H10	0.874 (5)	1.164 (4)	0.760 (4)	0.027 (10)*

Atomic displacement parameters (Ų)

	U^11	U^22	U^33	U^12	U^13	U^23
C1	0.0109 (12)	0.0101 (11)	0.0078 (12)	−0.0005 (9)	0.0008 (9)	0.0036 (9)
C2	0.0096 (12)	0.0113 (11)	0.0076 (12)	−0.0008 (9)	0.0007 (9)	0.0037 (9)
C3	0.0162 (13)	0.0124 (12)	0.0073 (12)	0.0010 (10)	0.0041 (9)	0.0035 (9)
C4	0.0177 (13)	0.0096 (12)	0.0118 (13)	0.0024 (10)	0.0037 (10)	0.0034 (9)
C5	0.0191 (14)	0.0104 (12)	0.0127 (13)	0.0025 (10)	0.0051 (10)	0.0060 (9)
C6	0.0151 (13)	0.0080 (11)	0.0101 (12)	−0.0007 (10)	0.0036 (9)	0.0015 (9)
C7	0.0127 (12)	0.0076 (11)	0.0106 (12)	0.0009 (9)	0.0053 (9)	0.0025 (9)
C8	0.0074 (12)	0.0105 (11)	0.0078 (11)	0.0007 (9)	0.0009 (9)	0.0030 (9)
C9	0.0080 (12)	0.0138 (12)	0.0103 (13)	0.0028 (10)	0.0037 (9)	0.0045 (9)
Eu1	0.00918 (8)	0.00665 (7)	0.00609 (7)	0.00141 (4)	0.00295 (4)	0.00217 (4)
N1	0.0159 (11)	0.0124 (10)	0.0056 (10)	−0.0002 (9)	0.0039 (8)	0.0014 (8)
O1	0.0162 (9)	0.0119 (8)	0.0077 (9)	−0.0008 (7)	0.0031 (7)	0.0027 (6)
O2	0.0256 (10)	0.0077 (8)	0.0102 (9)	0.0014 (7)	0.0067 (7)	0.0019 (7)
O3	0.0487 (14)	0.0073 (9)	0.0173 (10)	0.0068 (9)	0.0196 (9)	0.0049 (7)
O4	0.0101 (9)	0.0144 (9)	0.0126 (9)	0.0033 (7)	0.0047 (7)	0.0052 (7)
O5	0.0154 (9)	0.0194 (9)	0.0107 (9)	0.0078 (7)	0.0051 (7)	0.0088 (7)
O6	0.0128 (9)	0.0080 (8)	0.0129 (9)	0.0032 (7)	0.0067 (7)	0.0049 (6)
O7	0.0170 (9)	0.0095 (8)	0.0131 (9)	0.0045 (7)	0.0096 (7)	0.0047 (7)
O8	0.0125 (9)	0.0142 (9)	0.0082 (9)	−0.0020 (7)	0.0027 (7)	0.0020 (7)
O9	0.0173 (10)	0.0148 (9)	0.0098 (9)	−0.0066 (7)	0.0049 (7)	0.0038 (7)
O10	0.0118 (9)	0.0165 (9)	0.0123 (10)	−0.0015 (8)	0.0031 (7)	0.0016 (8)
O11	0.0274 (12)	0.0109 (9)	0.0122 (10)	0.0002 (8)	0.0090 (8)	0.0035 (8)

Geometric parameters (Å, º)

C1—O1	1.246 (3)	C9—O9^iii	1.266 (3)
C1—O2	1.258 (3)	C9—C9^iii	1.546 (5)
C1—C2	1.515 (3)	Eu1—O1	2.3333 (16)
C2—C6	1.384 (3)	Eu1—O5	2.4025 (18)
C2—C3	1.385 (3)	Eu1—O7	2.4348 (16)
C3—C4	1.395 (3)	Eu1—O6	2.4433 (17)
C3—H3	0.9300	Eu1—O4	2.4539 (17)
C4—O3	1.341 (3)	Eu1—O11	2.4776 (18)
C4—C5	1.383 (3)	Eu1—O9	2.4899 (17)
C5—N1	1.344 (3)	Eu1—O10	2.5118 (19)
C5—H5	0.9300	Eu1—O8	2.5142 (16)
C6—N1	1.328 (3)	N1—H1	0.83 (3)
C6—H6	0.9300	O3—H3A	0.8200
C7—O5^i	1.246 (3)	O5—C7^i	1.246 (3)
C7—O4	1.252 (3)	O7—C8^ii	1.241 (3)
C7—C7^i	1.569 (5)	O9—C9^iii	1.266 (3)
C8—O7^ii	1.241 (3)	O10—H7	0.76 (4)
C8—O6	1.260 (3)	O10—H8	0.92 (4)
C8—C8^ii	1.562 (5)	O11—H9	0.89 (4)
C9—O8	1.238 (3)	O11—H10	0.74 (4)
O1—C1—O2	125.5 (2)	O1—Eu1—O8	75.12 (6)
O1—C1—C2	117.7 (2)	O5—Eu1—O8	68.60 (6)
O2—C1—C2	116.8 (2)	O7—Eu1—O8	66.05 (6)
C6—C2—C3	119.3 (2)	O6—Eu1—O8	117.53 (5)
C6—C2—C1	119.8 (2)	O4—Eu1—O8	115.81 (6)
C3—C2—C1	120.9 (2)	O11—Eu1—O8	138.86 (6)
C2—C3—C4	120.1 (2)	O9—Eu1—O8	64.36 (5)
C2—C3—H3	119.9	O10—Eu1—O8	129.19 (6)
C4—C3—H3	119.9	O1—Eu1—C7^i	100.78 (6)
O3—C4—C5	123.0 (2)	O5—Eu1—C7^i	20.20 (6)
O3—C4—C3	118.5 (2)	O7—Eu1—C7^i	140.16 (6)
C5—C4—C3	118.5 (2)	O6—Eu1—C7^i	120.37 (6)
N1—C5—C4	119.3 (2)	O4—Eu1—C7^i	48.67 (6)
N1—C5—H5	120.4	O11—Eu1—C7^i	78.99 (6)
C4—C5—H5	120.4	O9—Eu1—C7^i	70.91 (6)
N1—C6—C2	119.0 (2)	O10—Eu1—C7^i	148.31 (6)
N1—C6—H6	120.5	O8—Eu1—C7^i	77.75 (6)
C2—C6—H6	120.5	O1—Eu1—C7	125.61 (6)
O5^i—C7—O4	125.9 (2)	O5—Eu1—C7	48.20 (6)
O5^i—C7—C7^i	116.6 (3)	O7—Eu1—C7	141.25 (6)
O4—C7—C7^i	117.5 (3)	O6—Eu1—C7	93.32 (6)
O7^ii—C8—O6	125.7 (2)	O4—Eu1—C7	20.65 (6)
O7^ii—C8—C8^ii	117.4 (3)	O11—Eu1—C7	75.30 (6)
O6—C8—C8^ii	116.9 (3)	O9—Eu1—C7	62.82 (6)
O8—C9—O9^iii	126.9 (2)	O10—Eu1—C7	132.68 (6)
O8—C9—C9^iii	118.7 (3)	O8—Eu1—C7	98.11 (6)
O9^iii—C9—C9^iii	114.4 (3)	C7^i—Eu1—C7	28.45 (8)
O1—Eu1—O5	80.96 (6)	O1—Eu1—C8^ii	102.84 (6)
O1—Eu1—O7	85.97 (6)	O5—Eu1—C8^ii	146.68 (6)
O5—Eu1—O7	134.62 (6)	O7—Eu1—C8^ii	19.51 (6)
O1—Eu1—O6	138.32 (6)	O6—Eu1—C8^ii	47.81 (6)
O5—Eu1—O6	140.49 (6)	O4—Eu1—C8^ii	119.19 (6)
O7—Eu1—O6	67.29 (5)	O11—Eu1—C8^ii	135.25 (6)
O1—Eu1—O4	137.52 (6)	O9—Eu1—C8^ii	71.90 (6)
O5—Eu1—O4	67.69 (6)	O10—Eu1—C8^ii	67.29 (6)
O7—Eu1—O4	136.49 (6)	O8—Eu1—C8^ii	80.29 (6)
O6—Eu1—O4	75.83 (6)	C7^i—Eu1—C8^ii	142.17 (6)
O1—Eu1—O11	76.53 (6)	C7—Eu1—C8^ii	129.65 (6)
O5—Eu1—O11	78.03 (7)	C6—N1—C5	123.8 (2)
O7—Eu1—O11	140.07 (7)	C6—N1—H1	120 (2)
O6—Eu1—O11	103.48 (6)	C5—N1—H1	116 (2)
O4—Eu1—O11	69.67 (6)	C1—O1—Eu1	158.00 (17)
O1—Eu1—O9	139.48 (6)	C4—O3—H3A	109.5
O5—Eu1—O9	83.77 (6)	C7—O4—Eu1	115.60 (15)
O7—Eu1—O9	78.60 (6)	C7^i—O5—Eu1	118.04 (15)
O6—Eu1—O9	67.69 (6)	C8—O6—Eu1	118.79 (14)
O4—Eu1—O9	66.30 (6)	C8^ii—O7—Eu1	119.54 (15)
O11—Eu1—O9	135.93 (6)	C9—O8—Eu1	118.26 (15)
O1—Eu1—O10	75.35 (6)	C9^iii—O9—Eu1	120.53 (15)
O5—Eu1—O10	143.27 (6)	Eu1—O10—H7	111 (3)
O7—Eu1—O10	71.49 (6)	Eu1—O10—H8	119 (2)
O6—Eu1—O10	66.30 (6)	H7—O10—H8	105 (3)
O4—Eu1—O10	113.98 (6)	Eu1—O11—H9	125 (3)
O11—Eu1—O10	69.47 (7)	Eu1—O11—H10	116 (3)
O9—Eu1—O10	131.87 (6)	H9—O11—H10	109 (4)

Symmetry codes: (i) −x+1, −y+2, −z+1; (ii) −x+2, −y+1, −z+1; (iii) −x+1, −y+1, −z+1.

Hydrogen-bond geometry (Å, º)

D—H···A	D—H	H···A	D···A	D—H···A
N1—H1···O9^iv	0.83 (3)	1.84 (3)	2.662 (3)	172 (3)
O3—H3A···O2^v	0.82	1.73	2.543 (2)	169
O10—H7···O4^vi	0.76 (4)	2.26 (4)	3.016 (2)	168 (4)
O10—H8···O2^vii	0.92 (4)	1.85 (4)	2.759 (3)	170 (3)
O11—H9···O6^vi	0.88 (4)	1.90 (4)	2.771 (3)	170 (4)
O11—H10···O3^viii	0.74 (4)	2.04 (4)	2.776 (3)	172 (4)

Symmetry codes: (iv) x, y, z+1; (v) x, y−1, z; (vi) −x+2, −y+2, −z+1; (vii) −x+2, −y+2, −z+2; (viii) x, y+1, z.