Supporting information
Crystallographic Information File (CIF) https://doi.org/10.1107/S1600536807029789/bi2197sup1.cif | |
Structure factor file (CIF format) https://doi.org/10.1107/S1600536807029789/bi2197Isup2.hkl |
CCDC reference: 1212035
A mixture of GdCl3 (0.5 mmol), NaOH (0.5 mmol), pyridine-2,6-dicarboxylic acid (0.5 mmol), H2O (8 ml) and ethanol (8 ml) in a 25 ml Teflon-lined stainless steel autoclave was kept at 433 K for three days. Colourless crystals were obtained after cooling to room temperature with a yield of 36%. Elemental analysis calculated: C 28.16, H 3.18, N 4.69%; found: C 28.50, H 3.22, N 4.76%.
The H atoms of the water molecule were located from difference Fourier maps and were refined with distance restraints of H···H = 1.38 (2)Å and O—H = 0.82 (2) Å. All other H atoms were placed in calculated positions with: a C—H bond distance of 0.93 Å and Uiso(H) = 1.2Ueq(C).
The title compound is isostructural with its LaIII (Guerriero et al., 1987; Ghosh & Bharadwaj, 2005), CeIII (Okabe et al., 2002; Ghosh & Bharadwaj, 2003; Rafizadeh et al., 2005; Ramezanipour et al., 2005), PrIII (Ghosh & Bharadwaj, 2003; Zhao et al., 2005), NdIII (Miao et al., 1992), SmIII (Liu et al., 2005; Liu et al., 2006; Rafizadeh et al., 2005; Song et al., 2005) and EuIII (Brayshaw et al., 2005) analogues.
The GdIII ion is nine-coordinated by four O and two N atoms from two independent tridentate pyridine-2,6-dicarboxylate ligands, one O atom belonging to a neighboring pyridine-2,6-dicarboxylate ligand and two water molecules (Fig. 1). The bridging pyridine-2,6-dicarboxylate ligand gives rise to infinite chains along the c-axis (Fig. 2). An extensive network of hydrogen bonds exists between the water molecules.
The isostructural lanthanide compounds are those with LaIII (Guerriero et al., 1987; Ghosh & Bharadwaj, 2005), CeIII (Okabe et al., 2002; Ghosh & Bharadwaj, 2003; Rafizadeh et al., 2005; Ramezanipour et al., 2005), PrIII (Ghosh & Bharadwaj, 2003; Zhao et al., 2005), NdIII (Miao et al., 1992), SmIII (Liu et al., 2005, 2006; Rafizadeh et al., 2005; Song et al., 2005) and EuIII (Brayshaw et al., 2005).
Data collection: SMART (Bruker 2001); cell refinement: SAINT-Plus (Bruker, 2001); data reduction: SAINT-Plus; program(s) used to solve structure: SHELXS97 (Sheldrick, 1997); program(s) used to refine structure: SHELXL97 (Sheldrick, 1997); molecular graphics: SHELXTL (Bruker, 2001); software used to prepare material for publication: SHELXTL.
[Gd(C7H3NO4)(C7H4NO4)(H2O)2]·4H2O | F(000) = 1172 |
Mr = 596.56 | Dx = 1.951 Mg m−3 |
Monoclinic, P21/c | Mo Kα radiation, λ = 0.71073 Å |
Hall symbol: -P 2ybc | Cell parameters from 3925 reflections |
a = 14.1267 (3) Å | θ = 1.5–26.0° |
b = 11.2787 (2) Å | µ = 3.34 mm−1 |
c = 13.0162 (2) Å | T = 293 K |
β = 101.728 (1)° | Cubic, colourless |
V = 2030.59 (6) Å3 | 0.10 × 0.10 × 0.10 mm |
Z = 4 |
Bruker SMART CCD diffractometer | 3925 independent reflections |
Radiation source: fine-focus sealed tube | 3237 reflections with I > 2σ(I) |
Graphite monochromator | Rint = 0.033 |
φ and ω scans | θmax = 26.0°, θmin = 1.5° |
Absorption correction: multi-scan (SADABS; Sheldrick, 1996) | h = −16→16 |
Tmin = 0.731, Tmax = 0.731 | k = −13→13 |
7168 measured reflections | l = −7→15 |
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)] = 0.037 | Hydrogen site location: inferred from neighbouring sites |
wR(F2) = 0.134 | H atoms treated by a mixture of independent and constrained refinement |
S = 1.00 | w = 1/[σ2(Fo2) + (0.1152P)2 + 2.6596P] where P = (Fo2 + 2Fc2)/3 |
3925 reflections | (Δ/σ)max < 0.001 |
317 parameters | Δρmax = 1.05 e Å−3 |
0 restraints | Δρmin = −1.13 e Å−3 |
[Gd(C7H3NO4)(C7H4NO4)(H2O)2]·4H2O | V = 2030.59 (6) Å3 |
Mr = 596.56 | Z = 4 |
Monoclinic, P21/c | Mo Kα radiation |
a = 14.1267 (3) Å | µ = 3.34 mm−1 |
b = 11.2787 (2) Å | T = 293 K |
c = 13.0162 (2) Å | 0.10 × 0.10 × 0.10 mm |
β = 101.728 (1)° |
Bruker SMART CCD diffractometer | 3925 independent reflections |
Absorption correction: multi-scan (SADABS; Sheldrick, 1996) | 3237 reflections with I > 2σ(I) |
Tmin = 0.731, Tmax = 0.731 | Rint = 0.033 |
7168 measured reflections |
R[F2 > 2σ(F2)] = 0.037 | 0 restraints |
wR(F2) = 0.134 | H atoms treated by a mixture of independent and constrained refinement |
S = 1.00 | Δρmax = 1.05 e Å−3 |
3925 reflections | Δρmin = −1.13 e Å−3 |
317 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 | ||
Gd1 | 0.26984 (3) | 0.29481 (3) | 0.64844 (3) | 0.0182 (3) | |
C1 | 0.4427 (8) | 0.5000 (9) | 0.6318 (8) | 0.031 (2) | |
C2 | 0.5030 (7) | 0.3903 (10) | 0.6329 (8) | 0.032 (2) | |
C3 | 0.6014 (9) | 0.3898 (13) | 0.6353 (11) | 0.052 (3) | |
H3 | 0.6354 | 0.4605 | 0.6362 | 0.063* | |
C4 | 0.6477 (11) | 0.2826 (13) | 0.6365 (17) | 0.041 (3) | |
H4 | 0.7141 | 0.2801 | 0.6399 | 0.084* | |
C5 | 0.5952 (9) | 0.1780 (13) | 0.6325 (13) | 0.055 (4) | |
H5 | 0.6253 | 0.1049 | 0.6313 | 0.066* | |
C6 | 0.4975 (7) | 0.1849 (9) | 0.6305 (8) | 0.027 (2) | |
C7 | 0.4325 (7) | 0.0764 (9) | 0.6274 (8) | 0.026 (2) | |
C8 | 0.1194 (6) | 0.5248 (8) | 0.6735 (7) | 0.0199 (18) | |
C9 | 0.1269 (6) | 0.5389 (7) | 0.5597 (6) | 0.0150 (15) | |
C10 | 0.0915 (7) | 0.6395 (8) | 0.5001 (7) | 0.0239 (19) | |
H10 | 0.0641 | 0.7026 | 0.5298 | 0.029* | |
C11 | 0.0990 (7) | 0.6412 (8) | 0.3934 (7) | 0.026 (2) | |
H11 | 0.0772 | 0.7068 | 0.3520 | 0.031* | |
C12 | 0.1382 (6) | 0.5472 (7) | 0.3510 (6) | 0.0206 (17) | |
H12 | 0.1411 | 0.5463 | 0.2803 | 0.025* | |
C13 | 0.1740 (6) | 0.4515 (7) | 0.4171 (6) | 0.0163 (16) | |
C14 | 0.2257 (6) | 0.3477 (7) | 0.3807 (7) | 0.0167 (17) | |
N1 | 0.4519 (6) | 0.2884 (6) | 0.6323 (6) | 0.0227 (18) | |
N2 | 0.1687 (5) | 0.4485 (6) | 0.5185 (5) | 0.0140 (13) | |
O1 | 0.3562 (5) | 0.4925 (6) | 0.6348 (5) | 0.0286 (15) | |
O2 | 0.4846 (6) | 0.5978 (7) | 0.6261 (7) | 0.049 (2) | |
H2 | 0.4491 | 0.6558 | 0.6226 | 0.073* | |
O3 | 0.3440 (5) | 0.0970 (6) | 0.6299 (5) | 0.0265 (14) | |
O4 | 0.4693 (5) | −0.0207 (6) | 0.6241 (7) | 0.0424 (19) | |
O5 | 0.0799 (6) | 0.6041 (6) | 0.7145 (5) | 0.0329 (16) | |
O6 | 0.1550 (5) | 0.4297 (5) | 0.7180 (4) | 0.0245 (14) | |
O7 | 0.2736 (5) | 0.2815 (5) | 0.4534 (5) | 0.0202 (14) | |
O8 | 0.2190 (5) | 0.3336 (6) | 0.2838 (4) | 0.0216 (13) | |
O9 | 0.1254 (5) | 0.1838 (6) | 0.5631 (5) | 0.0284 (15) | |
O10 | 0.3672 (6) | 0.3476 (7) | 0.8247 (5) | 0.0405 (19) | |
O11 | 0.9704 (6) | 0.0577 (6) | 0.5986 (6) | 0.0370 (18) | |
O12 | 0.7979 (9) | 0.4016 (10) | 0.9161 (12) | 0.090 (4) | |
O13 | 0.3766 (9) | 0.7743 (10) | 0.6153 (14) | 0.092 (4) | |
O14 | 0.0414 (5) | 0.3081 (6) | 0.8505 (6) | 0.0277 (16) | |
H21 | 0.125 (12) | 0.205 (12) | 0.503 (5) | 0.080* | |
H22 | 0.085 (9) | 0.134 (11) | 0.573 (10) | 0.080* | |
H23 | 0.407 (8) | 0.401 (11) | 0.839 (10) | 0.080* | |
H24 | 0.335 (10) | 0.333 (15) | 0.868 (9) | 0.080* | |
H25 | 0.968 (12) | 0.086 (10) | 0.655 (6) | 0.080* | |
H26 | 0.954 (12) | −0.014 (6) | 0.588 (10) | 0.080* | |
H27 | 0.855 (4) | 0.419 (16) | 0.918 (10) | 0.080* | |
H28 | 0.786 (10) | 0.398 (17) | 0.978 (6) | 0.080* | |
H29 | 0.383 (11) | 0.828 (12) | 0.660 (11) | 0.080* | |
H30 | 0.323 (6) | 0.744 (14) | 0.603 (13) | 0.080* | |
H31 | 0.005 (11) | 0.252 (10) | 0.843 (11) | 0.080* | |
H32 | 0.067 (11) | 0.324 (13) | 0.802 (8) | 0.080* |
U11 | U22 | U33 | U12 | U13 | U23 | |
Gd1 | 0.0194 (4) | 0.0192 (4) | 0.0153 (4) | 0.00107 (14) | 0.0021 (2) | 0.00124 (13) |
C1 | 0.039 (6) | 0.023 (5) | 0.032 (5) | −0.006 (4) | 0.006 (4) | 0.004 (4) |
C2 | 0.026 (5) | 0.036 (6) | 0.032 (5) | −0.012 (4) | 0.004 (4) | 0.002 (4) |
C3 | 0.031 (6) | 0.054 (8) | 0.075 (9) | −0.016 (6) | 0.019 (6) | −0.006 (6) |
C4 | 0.038 (5) | 0.037 (5) | 0.046 (5) | −0.001 (5) | 0.007 (5) | −0.001 (5) |
C5 | 0.024 (6) | 0.051 (7) | 0.093 (11) | −0.001 (6) | 0.019 (7) | −0.015 (8) |
C6 | 0.014 (5) | 0.033 (5) | 0.033 (5) | −0.002 (4) | 0.001 (4) | −0.003 (4) |
C7 | 0.016 (5) | 0.032 (5) | 0.030 (5) | −0.001 (4) | 0.003 (4) | 0.001 (4) |
C8 | 0.019 (4) | 0.022 (4) | 0.018 (4) | 0.001 (3) | 0.004 (3) | −0.001 (3) |
C9 | 0.015 (4) | 0.012 (4) | 0.017 (4) | 0.002 (3) | 0.003 (3) | −0.001 (3) |
C10 | 0.031 (5) | 0.020 (4) | 0.021 (4) | 0.008 (4) | 0.006 (4) | 0.001 (3) |
C11 | 0.033 (5) | 0.024 (5) | 0.018 (4) | 0.007 (4) | −0.003 (4) | 0.006 (3) |
C12 | 0.027 (5) | 0.021 (4) | 0.012 (4) | 0.006 (3) | 0.001 (3) | 0.002 (3) |
C13 | 0.016 (4) | 0.017 (4) | 0.015 (4) | −0.003 (3) | 0.001 (3) | −0.002 (3) |
C14 | 0.017 (4) | 0.017 (4) | 0.015 (4) | 0.001 (3) | 0.002 (3) | −0.001 (3) |
N1 | 0.020 (4) | 0.028 (4) | 0.019 (4) | 0.000 (3) | 0.002 (3) | 0.000 (3) |
N2 | 0.014 (3) | 0.014 (3) | 0.013 (3) | 0.003 (3) | 0.001 (3) | 0.002 (3) |
O1 | 0.028 (4) | 0.020 (3) | 0.036 (4) | −0.008 (3) | 0.001 (3) | 0.003 (3) |
O2 | 0.049 (5) | 0.037 (4) | 0.052 (5) | −0.022 (4) | −0.009 (4) | 0.008 (4) |
O3 | 0.027 (4) | 0.018 (3) | 0.034 (4) | 0.001 (3) | 0.004 (3) | 0.002 (3) |
O4 | 0.033 (4) | 0.023 (4) | 0.069 (5) | 0.013 (3) | 0.005 (4) | −0.002 (4) |
O5 | 0.052 (5) | 0.024 (3) | 0.027 (3) | 0.016 (3) | 0.018 (3) | 0.002 (3) |
O6 | 0.038 (4) | 0.023 (3) | 0.015 (3) | 0.012 (3) | 0.010 (3) | 0.004 (2) |
O7 | 0.027 (4) | 0.022 (3) | 0.012 (3) | 0.011 (2) | 0.003 (3) | 0.002 (2) |
O8 | 0.029 (4) | 0.021 (3) | 0.013 (3) | 0.006 (3) | 0.001 (3) | −0.002 (2) |
O9 | 0.032 (4) | 0.037 (4) | 0.015 (3) | −0.010 (3) | 0.002 (3) | 0.005 (3) |
O10 | 0.046 (5) | 0.056 (5) | 0.017 (3) | −0.032 (4) | 0.000 (3) | −0.001 (3) |
O11 | 0.051 (5) | 0.034 (4) | 0.032 (4) | −0.014 (3) | 0.025 (4) | −0.002 (3) |
O12 | 0.062 (7) | 0.047 (6) | 0.148 (12) | 0.013 (5) | −0.011 (7) | −0.004 (7) |
O13 | 0.066 (8) | 0.043 (6) | 0.163 (14) | 0.000 (5) | 0.013 (9) | −0.004 (7) |
O14 | 0.026 (4) | 0.033 (4) | 0.023 (4) | −0.002 (3) | 0.002 (3) | 0.001 (3) |
Gd1—O9 | 2.458 (7) | C9—N2 | 1.343 (10) |
Gd1—O3 | 2.497 (6) | C9—C10 | 1.408 (11) |
Gd1—O8i | 2.496 (6) | C10—C11 | 1.414 (12) |
Gd1—O10 | 2.496 (6) | C10—H10 | 0.930 |
Gd1—O6 | 2.523 (6) | C11—C12 | 1.363 (13) |
Gd1—O7 | 2.554 (6) | C11—H11 | 0.930 |
Gd1—O1 | 2.566 (6) | C12—C13 | 1.409 (11) |
Gd1—N1 | 2.624 (9) | C12—H12 | 0.930 |
Gd1—N2 | 2.631 (6) | C13—N2 | 1.338 (10) |
C1—O1 | 1.232 (13) | C13—C14 | 1.506 (11) |
C1—O2 | 1.261 (13) | C14—O8 | 1.256 (10) |
C1—C2 | 1.501 (15) | C14—O7 | 1.285 (10) |
C2—N1 | 1.356 (12) | O2—H2 | 0.820 |
C2—C3 | 1.383 (16) | O8—Gd1ii | 2.496 (6) |
C3—C4 | 1.37 (2) | O9—H21 | 0.82 (9) |
C3—H3 | 0.930 | O9—H22 | 0.83 (12) |
C4—C5 | 1.39 (2) | O10—H23 | 0.82 (13) |
C4—H4 | 0.930 | O10—H24 | 0.81 (13) |
C5—C6 | 1.377 (16) | O11—H25 | 0.81 (9) |
C5—H5 | 0.930 | O11—H26 | 0.85 (7) |
C6—N1 | 1.335 (13) | O12—H27 | 0.83 (9) |
C6—C7 | 1.526 (13) | O12—H28 | 0.86 (9) |
C7—O4 | 1.216 (12) | O13—H29 | 0.83 (15) |
C7—O3 | 1.278 (12) | O13—H30 | 0.82 (10) |
C8—O5 | 1.232 (11) | O14—H31 | 0.81 (12) |
C8—O6 | 1.273 (10) | O14—H32 | 0.81 (14) |
C8—C9 | 1.515 (11) | ||
O9—Gd1—O3 | 80.1 (2) | C6—C5—H5 | 120.7 |
O9—Gd1—O8i | 72.1 (2) | N1—C6—C5 | 122.2 (11) |
O3—Gd1—O8i | 74.7 (2) | N1—C6—C7 | 114.4 (9) |
O9—Gd1—O10 | 142.0 (2) | C5—C6—C7 | 123.4 (10) |
O3—Gd1—O10 | 98.0 (3) | O4—C7—O3 | 126.3 (9) |
O8i—Gd1—O10 | 70.9 (2) | O4—C7—C6 | 117.6 (9) |
O9—Gd1—O6 | 86.2 (2) | O3—C7—C6 | 116.0 (8) |
O3—Gd1—O6 | 152.5 (2) | O5—C8—O6 | 125.9 (8) |
O8i—Gd1—O6 | 78.4 (2) | O5—C8—C9 | 118.4 (8) |
O10—Gd1—O6 | 78.5 (3) | O6—C8—C9 | 115.7 (7) |
O9—Gd1—O7 | 72.8 (2) | N2—C9—C10 | 121.9 (7) |
O3—Gd1—O7 | 76.0 (2) | N2—C9—C8 | 115.7 (7) |
O8i—Gd1—O7 | 137.3 (2) | C10—C9—C8 | 122.3 (7) |
O10—Gd1—O7 | 144.0 (2) | C11—C10—C9 | 117.5 (8) |
O6—Gd1—O7 | 122.46 (19) | C11—C10—H10 | 121.2 |
O9—Gd1—O1 | 140.7 (2) | C9—C10—H10 | 121.3 |
O3—Gd1—O1 | 123.7 (2) | C12—C11—C10 | 120.3 (8) |
O8i—Gd1—O1 | 139.7 (2) | C12—C11—H11 | 119.9 |
O10—Gd1—O1 | 71.0 (2) | C10—C11—H11 | 119.8 |
O6—Gd1—O1 | 81.4 (2) | C11—C12—C13 | 118.3 (8) |
O7—Gd1—O1 | 82.9 (2) | C11—C12—H12 | 120.8 |
O9—Gd1—N1 | 133.4 (2) | C13—C12—H12 | 120.9 |
O3—Gd1—N1 | 62.0 (2) | N2—C13—C12 | 122.4 (7) |
O8i—Gd1—N1 | 117.9 (2) | N2—C13—C14 | 114.8 (7) |
O10—Gd1—N1 | 73.4 (3) | C12—C13—C14 | 122.7 (7) |
O6—Gd1—N1 | 139.3 (2) | O8—C14—O7 | 125.9 (7) |
O7—Gd1—N1 | 72.5 (2) | O8—C14—C13 | 118.2 (7) |
O1—Gd1—N1 | 62.0 (2) | O7—C14—C13 | 115.9 (7) |
O9—Gd1—N2 | 75.7 (2) | C6—N1—C2 | 118.9 (9) |
O3—Gd1—N2 | 135.2 (2) | C6—N1—Gd1 | 120.6 (6) |
O8i—Gd1—N2 | 129.7 (2) | C2—N1—Gd1 | 120.4 (6) |
O10—Gd1—N2 | 124.0 (3) | C9—N2—C13 | 119.4 (7) |
O6—Gd1—N2 | 61.85 (19) | C9—N2—Gd1 | 118.0 (5) |
O7—Gd1—N2 | 61.20 (19) | C13—N2—Gd1 | 121.2 (5) |
O1—Gd1—N2 | 65.6 (2) | C1—O1—Gd1 | 123.4 (6) |
N1—Gd1—N2 | 112.3 (2) | C1—O2—H2 | 114.00 |
O1—C1—O2 | 122.8 (10) | C7—O3—Gd1 | 126.7 (6) |
O1—C1—C2 | 120.5 (9) | C8—O6—Gd1 | 124.6 (5) |
O2—C1—C2 | 116.7 (10) | C14—O7—Gd1 | 125.7 (5) |
N1—C2—C3 | 121.8 (11) | C14—O8—Gd1ii | 144.0 (5) |
N1—C2—C1 | 113.4 (8) | Gd1—O9—H21 | 98 (10) |
C3—C2—C1 | 124.7 (10) | Gd1—O9—H22 | 144 (9) |
C2—C3—C4 | 118.6 (12) | H21—O9—H22 | 118 (13) |
C2—C3—H3 | 120.8 | Gd1—O10—H23 | 127 (10) |
C4—C3—H3 | 120.6 | Gd1—O10—H24 | 108 (10) |
C5—C4—C3 | 119.8 (14) | H23—O10—H24 | 117 (7) |
C5—C4—H4 | 120.1 | H25—O11—H26 | 118 (6) |
C3—C4—H4 | 120.1 | H27—O12—H28 | 111 (13) |
C4—C5—C6 | 118.6 (13) | H29—O13—H30 | 114 (16) |
C4—C5—H5 | 120.7 | H31—O14—H32 | 118 (7) |
Symmetry codes: (i) x, −y+1/2, z+1/2; (ii) x, −y+1/2, z−1/2. |
D—H···A | D—H | H···A | D···A | D—H···A |
O2—H2···O13 | 0.82 | 1.68 | 2.495 (9) | 180 |
O9—H21···O14ii | 0.82 (9) | 2.09 (10) | 2.782 (10) | 141 (13) |
O9—H22···O11iii | 0.83 (12) | 1.92 (13) | 2.728 (10) | 165 (16) |
O10—H23···O4iv | 0.82 (13) | 1.93 (12) | 2.713 (10) | 160 (17) |
O10—H24···O7i | 0.81 (13) | 2.01 (8) | 2.752 (9) | 152 (17) |
O11—H25···O5v | 0.81 (9) | 1.96 (7) | 2.719 (9) | 156 (14) |
O11—H26···O14v | 0.85 (7) | 2.15 (9) | 2.905 (10) | 147 (13) |
O12—H27···O11i | 0.83 (9) | 2.59 (12) | 3.072 (15) | 119 (11) |
O12—H28···O13v | 0.86 (9) | 2.75 (15) | 2.810 (18) | 85 (10) |
O13—H29···O4vi | 0.83 (15) | 2.20 (14) | 2.649 (14) | 114 (13) |
O13—H30···O12iv | 0.82 (10) | 2.44 (16) | 2.810 (18) | 108 (14) |
O14—H31···O5vii | 0.81 (12) | 2.10 (13) | 2.891 (10) | 165 (13) |
Symmetry codes: (i) x, −y+1/2, z+1/2; (ii) x, −y+1/2, z−1/2; (iii) x−1, y, z; (iv) −x+1, y+1/2, −z+3/2; (v) −x+1, y−1/2, −z+3/2; (vi) x, y+1, z; (vii) −x, y−1/2, −z+3/2. |
Experimental details
Crystal data | |
Chemical formula | [Gd(C7H3NO4)(C7H4NO4)(H2O)2]·4H2O |
Mr | 596.56 |
Crystal system, space group | Monoclinic, P21/c |
Temperature (K) | 293 |
a, b, c (Å) | 14.1267 (3), 11.2787 (2), 13.0162 (2) |
β (°) | 101.728 (1) |
V (Å3) | 2030.59 (6) |
Z | 4 |
Radiation type | Mo Kα |
µ (mm−1) | 3.34 |
Crystal size (mm) | 0.10 × 0.10 × 0.10 |
Data collection | |
Diffractometer | Bruker SMART CCD |
Absorption correction | Multi-scan (SADABS; Sheldrick, 1996) |
Tmin, Tmax | 0.731, 0.731 |
No. of measured, independent and observed [I > 2σ(I)] reflections | 7168, 3925, 3237 |
Rint | 0.033 |
(sin θ/λ)max (Å−1) | 0.617 |
Refinement | |
R[F2 > 2σ(F2)], wR(F2), S | 0.037, 0.134, 1.00 |
No. of reflections | 3925 |
No. of parameters | 317 |
H-atom treatment | H atoms treated by a mixture of independent and constrained refinement |
Δρmax, Δρmin (e Å−3) | 1.05, −1.13 |
Computer programs: SMART (Bruker 2001), SAINT-Plus (Bruker, 2001), SAINT-Plus, SHELXS97 (Sheldrick, 1997), SHELXL97 (Sheldrick, 1997), SHELXTL (Bruker, 2001), SHELXTL.
The title compound is isostructural with its LaIII (Guerriero et al., 1987; Ghosh & Bharadwaj, 2005), CeIII (Okabe et al., 2002; Ghosh & Bharadwaj, 2003; Rafizadeh et al., 2005; Ramezanipour et al., 2005), PrIII (Ghosh & Bharadwaj, 2003; Zhao et al., 2005), NdIII (Miao et al., 1992), SmIII (Liu et al., 2005; Liu et al., 2006; Rafizadeh et al., 2005; Song et al., 2005) and EuIII (Brayshaw et al., 2005) analogues.
The GdIII ion is nine-coordinated by four O and two N atoms from two independent tridentate pyridine-2,6-dicarboxylate ligands, one O atom belonging to a neighboring pyridine-2,6-dicarboxylate ligand and two water molecules (Fig. 1). The bridging pyridine-2,6-dicarboxylate ligand gives rise to infinite chains along the c-axis (Fig. 2). An extensive network of hydrogen bonds exists between the water molecules.