The title complex, [Eu(C6H4O2)3(H2O)2], has a double carboxylate-bridged infinite-chain structure, with one chelating carboxylate group on each Eu ion centre, which also binds to two water molecules to yield an eight-coordinate square-antiprismatic geometry, with Eu-O bond lengths in the range 2.338 (3)-2.594 (3) Å. The pyridine N atoms of the isonicotinate groups do not coordinate to the Eu ions; instead, they direct the formation of EuIII coordination polymers via hydrogen bonding with coordinated water molecules.
Supporting information
CCDC reference: 150378
Isonicotinic acid (0.1 g) and Eu(CF3COO)3 (0.1 g) were mixed with ethanol (1 ml) and water (0.1 ml) in a heavy-walled Pyrex tube. The Pyrex tube was sealed under vacuum (while frozen with liquid nitrogen). The tube was kept in oven at the temperature 350 K for 24 h, after which time, colourless prismatic crystals were obtained.
The deepest difference electron-density hole was 1.07 Å from the Eu1 atom.
Data collection: CAD-4 Software (Enraf-Nonius, 1989); cell refinement: CAD-4 Software; program(s) used to solve structure: SHELXS97 (Sheldrick, 1990); program(s) used to refine structure: SHELXTL (Sheldrick, 1997); software used to prepare material for publication: SHELXTL.
catena-poly[[[diaqua(isonicotinato-O,
O')europium(III)]-di-µ-isonicotinato-O:
O'] dihydrate]
top
Crystal data top
[Eu(C6H4O2)3(H2O)2] | F(000) = 1088 |
Mr = 554.30 | Dx = 1.903 Mg m−3 |
Monoclinic, P21/c | Mo Kα radiation, λ = 0.71073 Å |
a = 9.4860 (19) Å | Cell parameters from 25 reflections |
b = 18.974 (4) Å | θ = 2.6–6.9° |
c = 10.759 (2) Å | µ = 3.30 mm−1 |
β = 92.48 (3)° | T = 293 K |
V = 1934.7 (7) Å3 | Prism, colourless |
Z = 4 | 0.32 × 0.26 × 0.24 mm |
Data collection top
CAD-4 diffractometer | 3060 reflections with I > 2σ(I) |
Radiation source: fine-focus sealed tube | Rint = 0.017 |
Graphite monochromator | θmax = 25.0°, θmin = 2.2° |
ω–2θ scans | h = 0→11 |
Absorption correction: empirical (using intensity measurements) from ψ scan (North et al., 1968) | k = 0→22 |
Tmin = 0.348, Tmax = 0.452 | l = −12→12 |
3615 measured reflections | 3 standard reflections every 97 reflections |
3402 independent reflections | intensity decay: 0.0% |
Refinement top
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)] = 0.025 | Hydrogen site location: inferred from neighbouring sites |
wR(F2) = 0.070 | H-atom parameters constrained |
S = 1.09 | w = 1/[σ2(Fo2) + (0.046P)2 + 1.409P] where P = (Fo2 + 2Fc2)/3 |
3402 reflections | (Δ/σ)max = 0.002 |
271 parameters | Δρmax = 0.73 e Å−3 |
25 restraints | Δρmin = −2.01 e Å−3 |
Crystal data top
[Eu(C6H4O2)3(H2O)2] | V = 1934.7 (7) Å3 |
Mr = 554.30 | Z = 4 |
Monoclinic, P21/c | Mo Kα radiation |
a = 9.4860 (19) Å | µ = 3.30 mm−1 |
b = 18.974 (4) Å | T = 293 K |
c = 10.759 (2) Å | 0.32 × 0.26 × 0.24 mm |
β = 92.48 (3)° | |
Data collection top
CAD-4 diffractometer | 3060 reflections with I > 2σ(I) |
Absorption correction: empirical (using intensity measurements) from ψ scan (North et al., 1968) | Rint = 0.017 |
Tmin = 0.348, Tmax = 0.452 | 3 standard reflections every 97 reflections |
3615 measured reflections | intensity decay: 0.0% |
3402 independent reflections | |
Refinement top
R[F2 > 2σ(F2)] = 0.025 | 25 restraints |
wR(F2) = 0.070 | H-atom parameters constrained |
S = 1.09 | Δρmax = 0.73 e Å−3 |
3402 reflections | Δρmin = −2.01 e Å−3 |
271 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 | x | y | z | Uiso*/Ueq | |
Eu1 | 0.752779 (16) | 0.510153 (9) | 0.456300 (14) | 0.01684 (9) | |
O1W | 0.6382 (3) | 0.40522 (14) | 0.3657 (2) | 0.0292 (6) | |
H1 | 0.5424 | 0.3919 | 0.3775 | 0.035* | |
H2 | 0.6829 | 0.3689 | 0.3177 | 0.035* | |
O2W | 0.8836 (3) | 0.47286 (17) | 0.2768 (2) | 0.0323 (6) | |
H3 | 0.9648 | 0.4527 | 0.3000 | 0.039* | |
H4 | 0.8416 | 0.4494 | 0.2173 | 0.039* | |
O1 | 1.1216 (3) | 0.38761 (14) | 0.6106 (2) | 0.0301 (6) | |
O2 | 0.9155 (3) | 0.42765 (14) | 0.5368 (2) | 0.0291 (6) | |
O3 | 0.6445 (3) | 0.61205 (13) | 0.5816 (2) | 0.0258 (6) | |
O4 | 0.8466 (3) | 0.56611 (15) | 0.6481 (2) | 0.0281 (6) | |
O5 | 0.6047 (3) | 0.46244 (15) | 0.6070 (2) | 0.0300 (6) | |
O6 | 0.4040 (2) | 0.44150 (16) | 0.6971 (2) | 0.0314 (6) | |
N1 | 0.7539 (4) | 0.4242 (2) | 1.0543 (3) | 0.0439 (10) | |
N2 | 0.7412 (5) | 0.7223 (2) | 1.0056 (4) | 0.0545 (11) | |
N3 | 0.7828 (4) | 0.20768 (19) | 0.7625 (4) | 0.0409 (9) | |
C1 | 0.8081 (6) | 0.6612 (3) | 0.9960 (4) | 0.0591 (14) | |
H1A | 0.8551 | 0.6422 | 1.0694 | 0.071* | |
C2 | 0.8131 (5) | 0.6234 (3) | 0.8865 (4) | 0.0454 (11) | |
H2A | 0.8674 | 0.5808 | 0.8827 | 0.055* | |
C3 | 0.7398 (4) | 0.6478 (2) | 0.7817 (3) | 0.0269 (8) | |
C4 | 0.6666 (4) | 0.7107 (2) | 0.7908 (4) | 0.0331 (9) | |
H4A | 0.6136 | 0.7293 | 0.7201 | 0.040* | |
C5 | 0.6728 (5) | 0.7463 (2) | 0.9032 (4) | 0.0429 (11) | |
H5A | 0.6241 | 0.7906 | 0.9080 | 0.051* | |
C6 | 0.7435 (4) | 0.60703 (19) | 0.6625 (3) | 0.0229 (7) | |
C7 | 0.7178 (5) | 0.2477 (2) | 0.6754 (5) | 0.0429 (11) | |
H7A | 0.6220 | 0.2362 | 0.6511 | 0.052* | |
C8 | 0.7799 (4) | 0.3035 (2) | 0.6177 (4) | 0.0341 (9) | |
H8A | 0.7267 | 0.3316 | 0.5580 | 0.041* | |
C9 | 0.9186 (4) | 0.31954 (18) | 0.6490 (3) | 0.0226 (7) | |
C10 | 0.9890 (4) | 0.2773 (2) | 0.7360 (3) | 0.0277 (8) | |
H10A | 1.0865 | 0.2859 | 0.7586 | 0.033* | |
C11 | 0.9168 (5) | 0.2228 (2) | 0.7900 (4) | 0.0357 (9) | |
H11A | 0.9660 | 0.1944 | 0.8518 | 0.043* | |
C12 | 0.9917 (4) | 0.38275 (18) | 0.5938 (3) | 0.0214 (7) | |
C13 | 0.6142 (5) | 0.4175 (3) | 1.0415 (4) | 0.0475 (12) | |
H13A | 0.5628 | 0.4093 | 1.1151 | 0.057* | |
C14 | 0.5398 (4) | 0.4212 (3) | 0.9289 (3) | 0.0384 (10) | |
H14A | 0.4392 | 0.4149 | 0.9241 | 0.046* | |
C15 | 0.6128 (4) | 0.43401 (19) | 0.8225 (3) | 0.0237 (7) | |
C16 | 0.7585 (4) | 0.4397 (2) | 0.8339 (4) | 0.0318 (9) | |
H16A | 0.8133 | 0.4476 | 0.7622 | 0.038* | |
C17 | 0.8231 (5) | 0.4338 (3) | 0.9503 (4) | 0.0402 (10) | |
H17A | 0.9241 | 0.4368 | 0.9575 | 0.048* | |
C18 | 0.5350 (3) | 0.44648 (18) | 0.6990 (3) | 0.0199 (7) | |
Atomic displacement parameters (Å2) top | U11 | U22 | U33 | U12 | U13 | U23 |
Eu1 | 0.02142 (13) | 0.01718 (13) | 0.01167 (12) | −0.00061 (6) | −0.00198 (8) | 0.00027 (6) |
O1W | 0.0269 (13) | 0.0294 (15) | 0.0314 (14) | −0.0040 (11) | 0.0029 (11) | −0.0126 (12) |
O2W | 0.0277 (14) | 0.0491 (17) | 0.0197 (13) | 0.0032 (13) | −0.0043 (11) | −0.0107 (13) |
O1 | 0.0249 (13) | 0.0287 (14) | 0.0365 (15) | −0.0058 (11) | −0.0027 (11) | 0.0085 (12) |
O2 | 0.0332 (14) | 0.0249 (14) | 0.0293 (14) | 0.0050 (11) | 0.0022 (11) | 0.0088 (11) |
O3 | 0.0283 (13) | 0.0263 (14) | 0.0225 (13) | −0.0016 (11) | −0.0039 (11) | −0.0040 (10) |
O4 | 0.0258 (13) | 0.0366 (15) | 0.0216 (12) | 0.0022 (12) | −0.0031 (10) | −0.0104 (11) |
O5 | 0.0382 (15) | 0.0345 (15) | 0.0173 (12) | −0.0074 (13) | 0.0001 (11) | 0.0031 (12) |
O6 | 0.0273 (14) | 0.0425 (16) | 0.0239 (13) | −0.0008 (12) | −0.0059 (11) | 0.0059 (12) |
N1 | 0.054 (2) | 0.055 (3) | 0.0217 (18) | 0.0079 (17) | −0.0126 (17) | 0.0005 (15) |
N2 | 0.076 (3) | 0.055 (3) | 0.032 (2) | 0.005 (2) | −0.0035 (19) | −0.020 (2) |
N3 | 0.043 (2) | 0.0296 (19) | 0.051 (2) | −0.0093 (16) | 0.0104 (17) | 0.0121 (17) |
C1 | 0.079 (3) | 0.064 (3) | 0.033 (2) | 0.010 (3) | −0.012 (2) | −0.015 (2) |
C2 | 0.060 (3) | 0.044 (3) | 0.031 (2) | 0.010 (2) | −0.010 (2) | −0.013 (2) |
C3 | 0.0286 (19) | 0.031 (2) | 0.0216 (18) | −0.0055 (15) | 0.0045 (15) | −0.0086 (16) |
C4 | 0.037 (2) | 0.032 (2) | 0.031 (2) | −0.0011 (17) | 0.0019 (17) | −0.0062 (17) |
C5 | 0.051 (3) | 0.035 (2) | 0.044 (2) | −0.001 (2) | 0.007 (2) | −0.017 (2) |
C6 | 0.0228 (17) | 0.0234 (18) | 0.0225 (18) | −0.0053 (15) | 0.0017 (15) | −0.0055 (14) |
C7 | 0.034 (2) | 0.035 (2) | 0.059 (3) | −0.0092 (18) | −0.005 (2) | 0.011 (2) |
C8 | 0.031 (2) | 0.030 (2) | 0.041 (2) | −0.0033 (16) | −0.0066 (18) | 0.0118 (18) |
C9 | 0.0258 (18) | 0.0194 (18) | 0.0226 (18) | −0.0009 (14) | 0.0015 (14) | 0.0008 (14) |
C10 | 0.0272 (19) | 0.0278 (19) | 0.0278 (19) | −0.0004 (15) | −0.0013 (15) | 0.0053 (15) |
C11 | 0.044 (2) | 0.031 (2) | 0.032 (2) | 0.0020 (18) | 0.0003 (18) | 0.0126 (17) |
C12 | 0.0301 (19) | 0.0181 (17) | 0.0160 (16) | −0.0020 (14) | 0.0015 (14) | −0.0010 (13) |
C13 | 0.054 (3) | 0.067 (3) | 0.0221 (19) | 0.004 (2) | −0.0007 (18) | 0.0073 (19) |
C14 | 0.036 (2) | 0.060 (3) | 0.0196 (19) | −0.002 (2) | 0.0002 (17) | 0.0106 (19) |
C15 | 0.0276 (18) | 0.0236 (18) | 0.0195 (17) | 0.0022 (15) | −0.0041 (14) | 0.0014 (14) |
C16 | 0.032 (2) | 0.042 (2) | 0.0218 (19) | 0.0031 (18) | −0.0038 (16) | 0.0015 (17) |
C17 | 0.034 (2) | 0.055 (3) | 0.030 (2) | 0.004 (2) | −0.0162 (18) | 0.000 (2) |
C18 | 0.0269 (18) | 0.0166 (16) | 0.0157 (16) | −0.0006 (14) | −0.0020 (14) | 0.0008 (13) |
Geometric parameters (Å, º) top
Eu1—O2 | 2.338 (3) | N3—C11 | 1.324 (6) |
Eu1—O6i | 2.359 (3) | N3—C7 | 1.336 (6) |
Eu1—O5 | 2.370 (3) | C1—C2 | 1.381 (6) |
Eu1—O1ii | 2.403 (3) | C2—C3 | 1.378 (6) |
Eu1—O2W | 2.445 (3) | C3—C4 | 1.387 (6) |
Eu1—O1W | 2.450 (3) | C3—C6 | 1.499 (5) |
Eu1—O4 | 2.453 (2) | C4—C5 | 1.385 (6) |
Eu1—O3 | 2.594 (3) | C7—C8 | 1.374 (6) |
O1—C12 | 1.240 (4) | C8—C9 | 1.378 (5) |
O1—Eu1ii | 2.403 (3) | C9—C10 | 1.382 (5) |
O2—C12 | 1.259 (4) | C9—C12 | 1.519 (5) |
O3—C6 | 1.257 (4) | C10—C11 | 1.382 (5) |
O4—C6 | 1.263 (4) | C12—Eu1ii | 3.226 (3) |
O5—C18 | 1.252 (4) | C13—C14 | 1.377 (6) |
O6—C18 | 1.245 (3) | C14—C15 | 1.385 (5) |
O6—Eu1i | 2.359 (3) | C15—C16 | 1.386 (5) |
N1—C17 | 1.334 (5) | C15—C18 | 1.510 (4) |
N1—C13 | 1.332 (6) | C16—C17 | 1.375 (5) |
N2—C1 | 1.329 (7) | C18—Eu1i | 3.244 (3) |
N2—C5 | 1.335 (6) | | |
| | | |
O2—Eu1—O6i | 154.91 (10) | O3—Eu1—C18i | 74.65 (8) |
O2—Eu1—O5 | 83.80 (9) | C6—Eu1—C18i | 100.46 (9) |
O6i—Eu1—O5 | 104.64 (9) | C12ii—Eu1—C18i | 112.06 (8) |
O2—Eu1—O1ii | 108.86 (9) | C12—O1—Eu1ii | 121.2 (2) |
O6i—Eu1—O1ii | 77.44 (9) | C12—O2—Eu1 | 171.6 (2) |
O5—Eu1—O1ii | 146.04 (10) | C6—O3—Eu1 | 90.2 (2) |
O2—Eu1—O2W | 75.50 (9) | C6—O4—Eu1 | 96.6 (2) |
O6i—Eu1—O2W | 83.46 (9) | C18—O5—Eu1 | 169.3 (2) |
O5—Eu1—O2W | 139.98 (11) | C18—O6—Eu1i | 125.5 (2) |
O1ii—Eu1—O2W | 73.85 (10) | C17—N1—C13 | 116.7 (3) |
O2—Eu1—O1W | 82.98 (10) | C1—N2—C5 | 116.8 (4) |
O6i—Eu1—O1W | 77.42 (9) | C11—N3—C7 | 116.3 (3) |
O5—Eu1—O1W | 72.29 (9) | N2—C1—C2 | 123.6 (5) |
O1ii—Eu1—O1W | 138.94 (9) | C3—C2—C1 | 119.3 (4) |
O2W—Eu1—O1W | 71.48 (9) | C2—C3—C4 | 117.9 (4) |
O2—Eu1—O4 | 76.61 (10) | C2—C3—C6 | 119.8 (4) |
O6i—Eu1—O4 | 127.95 (10) | C4—C3—C6 | 122.3 (3) |
O5—Eu1—O4 | 78.13 (9) | C5—C4—C3 | 118.6 (4) |
O1ii—Eu1—O4 | 74.68 (9) | N2—C5—C4 | 123.7 (4) |
O2W—Eu1—O4 | 127.70 (9) | O3—C6—O4 | 121.3 (3) |
O1W—Eu1—O4 | 145.57 (9) | O3—C6—C3 | 120.6 (3) |
O2—Eu1—O3 | 125.19 (9) | O4—C6—C3 | 118.0 (3) |
O6i—Eu1—O3 | 79.74 (9) | O3—C6—Eu1 | 64.01 (18) |
O5—Eu1—O3 | 70.71 (9) | O4—C6—Eu1 | 57.61 (17) |
O1ii—Eu1—O3 | 76.50 (9) | C3—C6—Eu1 | 171.4 (3) |
O2W—Eu1—O3 | 148.43 (9) | N3—C7—C8 | 124.2 (4) |
O1W—Eu1—O3 | 129.30 (8) | C7—C8—C9 | 118.9 (4) |
O4—Eu1—O3 | 51.53 (8) | C8—C9—C10 | 117.8 (3) |
O2—Eu1—C6 | 100.54 (10) | C8—C9—C12 | 121.7 (3) |
O6i—Eu1—C6 | 104.54 (10) | C10—C9—C12 | 120.5 (3) |
O5—Eu1—C6 | 71.27 (10) | C9—C10—C11 | 119.0 (4) |
O1ii—Eu1—C6 | 75.41 (10) | N3—C11—C10 | 123.8 (4) |
O2W—Eu1—C6 | 145.59 (10) | O1—C12—O2 | 124.5 (3) |
O1W—Eu1—C6 | 142.72 (9) | O1—C12—C9 | 118.0 (3) |
O4—Eu1—C6 | 25.78 (9) | O2—C12—C9 | 117.5 (3) |
O3—Eu1—C6 | 25.82 (9) | O1—C12—Eu1ii | 39.57 (17) |
O2—Eu1—C12ii | 89.72 (9) | O2—C12—Eu1ii | 85.0 (2) |
O6i—Eu1—C12ii | 95.37 (9) | C9—C12—Eu1ii | 157.2 (2) |
O5—Eu1—C12ii | 145.76 (9) | N1—C13—C14 | 123.8 (4) |
O1ii—Eu1—C12ii | 19.19 (9) | C13—C14—C15 | 118.7 (4) |
O2W—Eu1—C12ii | 68.88 (10) | C14—C15—C16 | 118.2 (3) |
O1W—Eu1—C12ii | 140.26 (9) | C14—C15—C18 | 120.8 (3) |
O4—Eu1—C12ii | 67.67 (9) | C16—C15—C18 | 120.8 (3) |
O3—Eu1—C12ii | 86.25 (8) | C17—C16—C15 | 118.5 (4) |
C6—Eu1—C12ii | 77.01 (9) | N1—C17—C16 | 124.0 (4) |
O2—Eu1—C18i | 152.60 (9) | O6—C18—O5 | 124.5 (3) |
O6i—Eu1—C18i | 18.21 (8) | O6—C18—C15 | 116.9 (3) |
O5—Eu1—C18i | 86.50 (9) | O5—C18—C15 | 118.6 (3) |
O1ii—Eu1—C18i | 93.34 (8) | O6—C18—Eu1i | 36.31 (16) |
O2W—Eu1—C18i | 96.37 (9) | O5—C18—Eu1i | 89.6 (2) |
O1W—Eu1—C18i | 69.65 (9) | C15—C18—Eu1i | 149.4 (2) |
O4—Eu1—C18i | 126.16 (9) | | |
Symmetry codes: (i) −x+1, −y+1, −z+1; (ii) −x+2, −y+1, −z+1. |
Hydrogen-bond geometry (Å, º) top
D—H···A | D—H | H···A | D···A | D—H···A |
O1W—H1···O3i | 0.95 (7) | 1.84 (7) | 2.784 (4) | 165 (8) |
O1W—H2···N3iii | 0.97 (1) | 1.84 (7) | 2.799 (5) | 166 (6) |
O2W—H3···O4ii | 0.88 (6) | 1.88 (5) | 2.752 (4) | 165 (3) |
O2W—H4···N1iv | 0.86 (3) | 1.96 (7) | 2.800 (4) | 161 (9) |
C16—H16A···O4 | 0.96 (1) | 2.58 (8) | 3.255 (5) | 126 (7) |
Symmetry codes: (i) −x+1, −y+1, −z+1; (ii) −x+2, −y+1, −z+1; (iii) x, −y+1/2, z−1/2; (iv) x, y, z−1. |
Experimental details
Crystal data |
Chemical formula | [Eu(C6H4O2)3(H2O)2] |
Mr | 554.30 |
Crystal system, space group | Monoclinic, P21/c |
Temperature (K) | 293 |
a, b, c (Å) | 9.4860 (19), 18.974 (4), 10.759 (2) |
β (°) | 92.48 (3) |
V (Å3) | 1934.7 (7) |
Z | 4 |
Radiation type | Mo Kα |
µ (mm−1) | 3.30 |
Crystal size (mm) | 0.32 × 0.26 × 0.24 |
|
Data collection |
Diffractometer | CAD-4 diffractometer |
Absorption correction | Empirical (using intensity measurements) from ψ scan (North et al., 1968) |
Tmin, Tmax | 0.348, 0.452 |
No. of measured, independent and observed [I > 2σ(I)] reflections | 3615, 3402, 3060 |
Rint | 0.017 |
(sin θ/λ)max (Å−1) | 0.594 |
|
Refinement |
R[F2 > 2σ(F2)], wR(F2), S | 0.025, 0.070, 1.09 |
No. of reflections | 3402 |
No. of parameters | 271 |
No. of restraints | 25 |
H-atom treatment | H-atom parameters constrained |
Δρmax, Δρmin (e Å−3) | 0.73, −2.01 |
Selected bond lengths (Å) topEu1—O2 | 2.338 (3) | Eu1—O2W | 2.445 (3) |
Eu1—O6i | 2.359 (3) | Eu1—O1W | 2.450 (3) |
Eu1—O5 | 2.370 (3) | Eu1—O4 | 2.453 (2) |
Eu1—O1ii | 2.403 (3) | Eu1—O3 | 2.594 (3) |
Symmetry codes: (i) −x+1, −y+1, −z+1; (ii) −x+2, −y+1, −z+1. |
Hydrogen-bond geometry (Å, º) top
D—H···A | D—H | H···A | D···A | D—H···A |
O1W—H1···O3i | 0.95 (7) | 1.84 (7) | 2.784 (4) | 165 (8) |
O1W—H2···N3iii | 0.97 (1) | 1.84 (7) | 2.799 (5) | 166 (6) |
O2W—H3···O4ii | 0.88 (6) | 1.88 (5) | 2.752 (4) | 165 (3) |
O2W—H4···N1iv | 0.86 (3) | 1.96 (7) | 2.800 (4) | 161 (9) |
Symmetry codes: (i) −x+1, −y+1, −z+1; (ii) −x+2, −y+1, −z+1; (iii) x, −y+1/2, z−1/2; (iv) x, y, z−1. |
There has been considerable interest in rare earth isonicotinates (Moore et al., 1972; Chupakhina et al., 1963; Xu et al., 1997; Ye & Qin, 1991). In this paper, we report that catena-poly[[[diaqua(isonicotinato-O,O')europium(III)]-di-µ-isonicotinato-O:O'] dihydrate], (I), has a one-dimensional chain structure instead of the dimers reported for SmIII and LaIII isonicotinates (Moore et al., 1972).
In the title compound, the isonicotinates are coordinated to the EuIII ions solely through the carboxylate O atoms, leaving the pyridine N atoms uncoordinated, and two isonicotinates act as bridging ligands between all adjacent Eu ions, thus forming a one-dimensional structure. In other words, the complex has a double carboxylate-bridged infinite chain, with one chelating carboxylate group on each Eu ion centre. The chelating carboxyl groups of isonicotinate have two Eu—O distances of 2.594 (3) and 2.454 (3) Å. A prominent feature is that the distances of the bridging isoniconates have two shorter Eu—O distances: O1ii is 2.403 (3) Å from Eu1 and O2 is 2.338 (3) Å from Eu1, which represents a weak interaction between the metal ion and the C atom of the carboxylate group (see Table 1 for symmetry code).
The coordination sphere of each Eu ion is completed by two water molecules to yield an eight-coordinate square-antiprismatic geometry. The Eu1—OW1 and Eu1—OW2 bond lengths are 2.449 (3) and 2.444 (3) Å, respectively. The presence of water molecules permits hydrogen bonding to the N and O atoms of adjacent chain units, whose relevant geometric parameters are quoted in Table 2. This hydrogen bonding occurs between different chain units, so that the bulk structure is bound together by these hydrogen bonds into a three-dimensional network.