metal-organic compounds
Tetraaquabis(biuret-κ2O,O′)gadolinium(III) trichloride
aDepartment of Chemistry, University of Aberdeen, Meston Walk, Aberdeen AB24 3UE, Scotland
*Correspondence e-mail: w.harrison@abdn.ac.uk
In the title compound, [Gd(C2H5N3O2)2(H2O)4]Cl3, which is isostrucutural with its yttrium analogue, the Gd3+ ion (site symmetry 2) is bonded to eight O atoms (arising from two O,O′-bidentate biuret molecules and four water molecules) in a distorted square-antiprismatic arrangement. A network of N—H⋯O, N—H⋯Cl and O—H⋯Cl hydrogen bonds helps to establish the packing, leading to a three-dimensional network. One of the chloride ions has 2.
Related literature
For related structures, see: Haddad (1987, 1988); Harrison (2008). For related literature, see: Bernstein et al. (1995). For valence-sum calculations, see: Brese & O'Keeffe (1991).
Experimental
Crystal data
|
Refinement
|
|
Data collection: SMART (Bruker, 1999); cell SAINT (Bruker, 1999); data reduction: SAINT; program(s) used to solve structure: SHELXS97 (Sheldrick, 2008); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008); molecular graphics: ORTEP-3 (Farrugia, 1997); software used to prepare material for publication: SHELXL97.
Supporting information
10.1107/S1600536808008660/sg2230sup1.cif
contains datablocks I, global. DOI:Structure factors: contains datablock I. DOI: 10.1107/S1600536808008660/sg2230Isup2.hkl
0.1 M Aqueous solutions of GdCl3 (10 ml) and biuret (10 ml) were mixed and a small quantity of dilute hydrochloric acid was added, to result in a colourless solution. Colourless blocks of (I) grew over several days as the water slowly evaporated.
The crystal quality was rather poor, with smeared and split peaks evident in the diffraction pattern.
The N-bound hydrogen atoms were geometrically placed (N—H = 0.88 Å) and refined as riding with Uiso(H) = 1.2Ueq(N). The water H atoms were located in difference maps and refined as riding in their as-found relative positions with Uiso(H) = 1.2Ueq(O).
The highest difference peak and deepest difference hole are 0.71Å and 0.75Å from Gd1, respectively.
Data collection: SMART (Bruker, 1999); cell
SAINT (Bruker, 1999); data reduction: SAINT (Bruker, 1999); program(s) used to solve structure: SHELXS97 (Sheldrick, 2008); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008); molecular graphics: ORTEP-3 (Farrugia, 1997); software used to prepare material for publication: SHELXL97 (Sheldrick, 2008).Fig. 1. View of the molecular structure of (I) showing 50% displacement ellipsoids (arbitrary spheres for the H atoms). Symmetry code: (i) -x, y, 3/2 - z. |
[Gd(C2H5N3O2)2(H2O)4]Cl3 | F(000) = 1052 |
Mr = 541.84 | Dx = 2.077 Mg m−3 |
Monoclinic, C2/c | Mo Kα radiation, λ = 0.71073 Å |
Hall symbol: -C 2yc | Cell parameters from 6423 reflections |
a = 7.6501 (3) Å | θ = 2.4–32.5° |
b = 13.2164 (5) Å | µ = 4.33 mm−1 |
c = 17.4557 (6) Å | T = 293 K |
β = 100.961 (1)° | Slab, colourless |
V = 1732.69 (11) Å3 | 0.47 × 0.34 × 0.06 mm |
Z = 4 |
Bruker SMART1000 CCD diffractometer | 3134 independent reflections |
Radiation source: fine-focus sealed tube | 2902 reflections with I > 2σ(I) |
Graphite monochromator | Rint = 0.025 |
ω scans | θmax = 32.5°, θmin = 2.4° |
Absorption correction: multi-scan (SADABS; Bruker, 1999) | h = −11→9 |
Tmin = 0.235, Tmax = 0.781 | k = −19→18 |
8649 measured reflections | l = −19→26 |
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)] = 0.033 | Hydrogen site location: difmap (O-H) and geom (N-H) |
wR(F2) = 0.088 | H-atom parameters constrained |
S = 1.06 | w = 1/[σ2(Fo2) + (0.0654P)2] where P = (Fo2 + 2Fc2)/3 |
3134 reflections | (Δ/σ)max < 0.001 |
101 parameters | Δρmax = 2.99 e Å−3 |
0 restraints | Δρmin = −3.45 e Å−3 |
[Gd(C2H5N3O2)2(H2O)4]Cl3 | V = 1732.69 (11) Å3 |
Mr = 541.84 | Z = 4 |
Monoclinic, C2/c | Mo Kα radiation |
a = 7.6501 (3) Å | µ = 4.33 mm−1 |
b = 13.2164 (5) Å | T = 293 K |
c = 17.4557 (6) Å | 0.47 × 0.34 × 0.06 mm |
β = 100.961 (1)° |
Bruker SMART1000 CCD diffractometer | 3134 independent reflections |
Absorption correction: multi-scan (SADABS; Bruker, 1999) | 2902 reflections with I > 2σ(I) |
Tmin = 0.235, Tmax = 0.781 | Rint = 0.025 |
8649 measured reflections |
R[F2 > 2σ(F2)] = 0.033 | 0 restraints |
wR(F2) = 0.088 | H-atom parameters constrained |
S = 1.06 | Δρmax = 2.99 e Å−3 |
3134 reflections | Δρmin = −3.45 e Å−3 |
101 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 | 0.0000 | 0.106486 (13) | 0.7500 | 0.02252 (7) | |
Cl1 | −0.04157 (10) | 0.33393 (7) | 0.50790 (4) | 0.03672 (16) | |
Cl2 | 0.5000 | 0.30307 (10) | 0.7500 | 0.0389 (2) | |
O1 | 0.2531 (3) | 0.02702 (18) | 0.71963 (13) | 0.0310 (4) | |
O2 | −0.0822 (3) | 0.01130 (17) | 0.63327 (12) | 0.0305 (4) | |
N1 | 0.4595 (4) | −0.0112 (3) | 0.64845 (18) | 0.0434 (7) | |
H1 | 0.5423 | 0.0169 | 0.6820 | 0.052* | |
H2 | 0.4845 | −0.0387 | 0.6072 | 0.052* | |
N2 | 0.1720 (3) | −0.0598 (2) | 0.60404 (15) | 0.0295 (5) | |
H3 | 0.2119 | −0.0977 | 0.5712 | 0.035* | |
N3 | −0.1037 (4) | −0.1127 (2) | 0.5433 (2) | 0.0371 (6) | |
H4 | −0.2181 | −0.1098 | 0.5337 | 0.044* | |
H5 | −0.0497 | −0.1552 | 0.5186 | 0.044* | |
C1 | 0.2950 (4) | −0.0121 (2) | 0.66032 (16) | 0.0269 (5) | |
C2 | −0.0103 (4) | −0.0513 (2) | 0.59616 (16) | 0.0265 (5) | |
O3 | −0.2462 (3) | 0.18787 (18) | 0.66543 (13) | 0.0360 (5) | |
H6 | −0.2805 | 0.1748 | 0.6199 | 0.043* | |
H7 | −0.3244 | 0.2160 | 0.6810 | 0.043* | |
O4 | 0.1191 (3) | 0.2294 (2) | 0.67206 (16) | 0.0502 (7) | |
H8 | 0.0833 | 0.2534 | 0.6327 | 0.060* | |
H9 | 0.2181 | 0.2507 | 0.6743 | 0.060* |
U11 | U22 | U33 | U12 | U13 | U23 | |
Gd1 | 0.01907 (9) | 0.02952 (10) | 0.01740 (9) | 0.000 | −0.00047 (6) | 0.000 |
Cl1 | 0.0337 (3) | 0.0470 (4) | 0.0268 (3) | 0.0011 (3) | −0.0007 (2) | −0.0067 (3) |
Cl2 | 0.0301 (4) | 0.0496 (6) | 0.0377 (5) | 0.000 | 0.0081 (4) | 0.000 |
O1 | 0.0217 (8) | 0.0441 (12) | 0.0257 (9) | 0.0024 (8) | 0.0006 (7) | −0.0071 (8) |
O2 | 0.0251 (9) | 0.0359 (10) | 0.0275 (9) | 0.0038 (8) | −0.0024 (7) | −0.0077 (8) |
N1 | 0.0233 (11) | 0.073 (2) | 0.0345 (14) | −0.0075 (12) | 0.0071 (10) | −0.0178 (14) |
N2 | 0.0240 (10) | 0.0363 (12) | 0.0269 (11) | 0.0004 (9) | 0.0018 (8) | −0.0083 (9) |
N3 | 0.0297 (13) | 0.0416 (15) | 0.0364 (15) | −0.0020 (9) | −0.0025 (11) | −0.0147 (11) |
C1 | 0.0227 (11) | 0.0322 (12) | 0.0241 (11) | 0.0010 (9) | 0.0005 (9) | −0.0008 (9) |
C2 | 0.0247 (11) | 0.0296 (12) | 0.0231 (11) | 0.0000 (9) | −0.0010 (9) | −0.0016 (9) |
O3 | 0.0337 (10) | 0.0484 (13) | 0.0228 (9) | 0.0135 (9) | −0.0027 (7) | −0.0022 (9) |
O4 | 0.0384 (13) | 0.0637 (17) | 0.0423 (14) | −0.0157 (12) | −0.0084 (10) | 0.0257 (12) |
Gd1—O1i | 2.350 (2) | N1—H2 | 0.8600 |
Gd1—O1 | 2.350 (2) | N2—C1 | 1.377 (4) |
Gd1—O2 | 2.375 (2) | N2—C2 | 1.380 (4) |
Gd1—O2i | 2.375 (2) | N2—H3 | 0.8600 |
Gd1—O4i | 2.407 (3) | N3—C2 | 1.330 (4) |
Gd1—O4 | 2.407 (3) | N3—H4 | 0.8600 |
Gd1—O3i | 2.414 (2) | N3—H5 | 0.8600 |
Gd1—O3 | 2.414 (2) | O3—H6 | 0.8067 |
O1—C1 | 1.253 (4) | O3—H7 | 0.7949 |
O2—C2 | 1.242 (3) | O4—H8 | 0.7597 |
N1—C1 | 1.314 (4) | O4—H9 | 0.8018 |
N1—H1 | 0.8600 | ||
O1i—Gd1—O1 | 126.90 (12) | O4—Gd1—O3 | 71.88 (8) |
O1i—Gd1—O2 | 82.06 (8) | O3i—Gd1—O3 | 127.08 (12) |
O1—Gd1—O2 | 70.41 (7) | C1—O1—Gd1 | 136.27 (18) |
O1i—Gd1—O2i | 70.41 (7) | C2—O2—Gd1 | 136.83 (18) |
O1—Gd1—O2i | 82.06 (8) | C1—N1—H1 | 120.0 |
O2—Gd1—O2i | 116.04 (11) | C1—N1—H2 | 120.0 |
O1i—Gd1—O4i | 75.96 (10) | H1—N1—H2 | 120.0 |
O1—Gd1—O4i | 147.78 (8) | C1—N2—C2 | 125.1 (3) |
O2—Gd1—O4i | 140.85 (7) | C1—N2—H3 | 117.4 |
O2i—Gd1—O4i | 86.53 (9) | C2—N2—H3 | 117.4 |
O1i—Gd1—O4 | 147.78 (8) | C2—N3—H4 | 120.0 |
O1—Gd1—O4 | 75.96 (10) | C2—N3—H5 | 120.0 |
O2—Gd1—O4 | 86.53 (9) | H4—N3—H5 | 120.0 |
O2i—Gd1—O4 | 140.85 (8) | O1—C1—N1 | 122.0 (3) |
O4i—Gd1—O4 | 95.10 (17) | O1—C1—N2 | 122.1 (3) |
O1i—Gd1—O3i | 129.93 (8) | N1—C1—N2 | 115.9 (3) |
O1—Gd1—O3i | 75.91 (8) | O2—C2—N3 | 122.4 (3) |
O2—Gd1—O3i | 144.00 (8) | O2—C2—N2 | 122.7 (2) |
O2i—Gd1—O3i | 70.30 (7) | N3—C2—N2 | 114.8 (3) |
O4i—Gd1—O3i | 71.88 (9) | Gd1—O3—H6 | 125.2 |
O4—Gd1—O3i | 73.11 (8) | Gd1—O3—H7 | 123.3 |
O1i—Gd1—O3 | 75.91 (8) | H6—O3—H7 | 108.2 |
O1—Gd1—O3 | 129.93 (8) | Gd1—O4—H8 | 133.1 |
O2—Gd1—O3 | 70.30 (7) | Gd1—O4—H9 | 131.7 |
O2i—Gd1—O3 | 144.00 (8) | H8—O4—H9 | 94.1 |
O4i—Gd1—O3 | 73.11 (8) | ||
O1i—Gd1—O1—C1 | 81.6 (3) | O4—Gd1—O2—C2 | 85.5 (3) |
O2—Gd1—O1—C1 | 18.4 (3) | O3i—Gd1—O2—C2 | 30.9 (4) |
O2i—Gd1—O1—C1 | 139.7 (3) | O3—Gd1—O2—C2 | 157.5 (3) |
O4i—Gd1—O1—C1 | −149.9 (3) | Gd1—O1—C1—N1 | 149.2 (3) |
O4—Gd1—O1—C1 | −72.9 (3) | Gd1—O1—C1—N2 | −31.6 (5) |
O3i—Gd1—O1—C1 | −148.7 (3) | C2—N2—C1—O1 | 15.1 (5) |
O3—Gd1—O1—C1 | −21.8 (3) | C2—N2—C1—N1 | −165.6 (3) |
O1i—Gd1—O2—C2 | −124.7 (3) | Gd1—O2—C2—N3 | 161.3 (2) |
O1—Gd1—O2—C2 | 9.2 (3) | Gd1—O2—C2—N2 | −21.7 (5) |
O2i—Gd1—O2—C2 | −61.1 (3) | C1—N2—C2—O2 | 9.9 (5) |
O4i—Gd1—O2—C2 | 179.3 (3) | C1—N2—C2—N3 | −172.8 (3) |
Symmetry code: (i) −x, y, −z+3/2. |
D—H···A | D—H | H···A | D···A | D—H···A |
N1—H1···O1ii | 0.86 | 2.10 | 2.910 (4) | 157 |
N1—H2···Cl1iii | 0.86 | 2.40 | 3.194 (3) | 154 |
N2—H3···Cl1iii | 0.86 | 2.53 | 3.315 (3) | 153 |
N3—H4···Cl1iv | 0.86 | 2.54 | 3.363 (3) | 161 |
N3—H5···Cl1v | 0.86 | 2.53 | 3.311 (3) | 151 |
O3—H6···Cl1vi | 0.81 | 2.39 | 3.163 (2) | 162 |
O3—H7···Cl2vii | 0.79 | 2.28 | 3.059 (2) | 167 |
O4—H8···Cl1 | 0.76 | 2.45 | 3.208 (2) | 178 |
O4—H9···Cl2 | 0.80 | 2.41 | 3.127 (2) | 150 |
Symmetry codes: (ii) −x+1, y, −z+3/2; (iii) x+1/2, y−1/2, z; (iv) x−1/2, y−1/2, z; (v) −x, −y, −z+1; (vi) −x−1/2, −y+1/2, −z+1; (vii) x−1, y, z. |
Experimental details
Crystal data | |
Chemical formula | [Gd(C2H5N3O2)2(H2O)4]Cl3 |
Mr | 541.84 |
Crystal system, space group | Monoclinic, C2/c |
Temperature (K) | 293 |
a, b, c (Å) | 7.6501 (3), 13.2164 (5), 17.4557 (6) |
β (°) | 100.961 (1) |
V (Å3) | 1732.69 (11) |
Z | 4 |
Radiation type | Mo Kα |
µ (mm−1) | 4.33 |
Crystal size (mm) | 0.47 × 0.34 × 0.06 |
Data collection | |
Diffractometer | Bruker SMART1000 CCD diffractometer |
Absorption correction | Multi-scan (SADABS; Bruker, 1999) |
Tmin, Tmax | 0.235, 0.781 |
No. of measured, independent and observed [I > 2σ(I)] reflections | 8649, 3134, 2902 |
Rint | 0.025 |
(sin θ/λ)max (Å−1) | 0.755 |
Refinement | |
R[F2 > 2σ(F2)], wR(F2), S | 0.033, 0.088, 1.06 |
No. of reflections | 3134 |
No. of parameters | 101 |
H-atom treatment | H-atom parameters constrained |
Δρmax, Δρmin (e Å−3) | 2.99, −3.45 |
Computer programs: SMART (Bruker, 1999), SAINT (Bruker, 1999), SHELXS97 (Sheldrick, 2008), SHELXL97 (Sheldrick, 2008), ORTEP-3 (Farrugia, 1997).
D—H···A | D—H | H···A | D···A | D—H···A |
N1—H1···O1i | 0.86 | 2.10 | 2.910 (4) | 157 |
N1—H2···Cl1ii | 0.86 | 2.40 | 3.194 (3) | 154 |
N2—H3···Cl1ii | 0.86 | 2.53 | 3.315 (3) | 153 |
N3—H4···Cl1iii | 0.86 | 2.54 | 3.363 (3) | 161 |
N3—H5···Cl1iv | 0.86 | 2.53 | 3.311 (3) | 151 |
O3—H6···Cl1v | 0.81 | 2.39 | 3.163 (2) | 162 |
O3—H7···Cl2vi | 0.79 | 2.28 | 3.059 (2) | 167 |
O4—H8···Cl1 | 0.76 | 2.45 | 3.208 (2) | 178 |
O4—H9···Cl2 | 0.80 | 2.41 | 3.127 (2) | 150 |
Symmetry codes: (i) −x+1, y, −z+3/2; (ii) x+1/2, y−1/2, z; (iii) x−1/2, y−1/2, z; (iv) −x, −y, −z+1; (v) −x−1/2, −y+1/2, −z+1; (vi) x−1, y, z. |
References
Bernstein, J., Davis, R. E., Shimoni, L. & Chang, N.-L. (1995). Angew. Chem. Int. Ed. Engl. 34, 1555–1573. CrossRef CAS Web of Science Google Scholar
Brese, N. E. & O'Keeffe, M. (1991). Acta Cryst. B47, 192–197. CrossRef CAS Web of Science IUCr Journals Google Scholar
Bruker (1999). SMART, SAINT and SADABS. Bruker AXS Inc., Madison, Wisconsin, USA. Google Scholar
Farrugia, L. J. (1997). J. Appl. Cryst. 30, 565. CrossRef IUCr Journals Google Scholar
Haddad, S. F. (1987). Acta Cryst. C43, 1882–1885. CSD CrossRef CAS IUCr Journals Google Scholar
Haddad, S. F. (1988). Acta Cryst. C44, 815–818. CSD CrossRef CAS Web of Science IUCr Journals Google Scholar
Harrison, W. T. A. (2008). Acta Cryst. E64, m619. Web of Science CSD CrossRef IUCr Journals Google Scholar
Sheldrick, G. M. (2008). Acta Cryst. A64, 112–122. Web of Science CrossRef CAS IUCr Journals Google Scholar
This is an open-access article distributed under the terms of the Creative Commons Attribution (CC-BY) Licence, which permits unrestricted use, distribution, and reproduction in any medium, provided the original authors and source are cited.
The title compound, (I), is isostructural with its recently described yttrium-containing analogue (Harrison, 2008).
The complete [Gd(biur)2(H2O)4]3+ (biur = biuret, C2H5N3O2) complex ion in (I) is generated by crystallographic 2-fold symmetry, with the metal atom lying on the rotation axis. Two uncoordinated chloride ions, one of which has site symmetry 2, complete the structure (Fig. 1) of (I).
The resulting GdO8 polyhedral geometry in (I) (Table 1) is a distorted square antiprism. The nominal square face formed by atoms O1, O2, O1i and O2i (i = -x, y, 3/2 - z) is reasonably regular, but the second face formed by the four water molecules (O3, O4, O3i and O4i) is much more distorted, and the diagonal O3···O3i O4···O4i distances of 4.322 (4)Å and 3.551 (4) Å, respectively, are very different. Gd1 deviates from the mean planes of O1/O2/O1i/O2i and O3/O4/O3i/O4i by 1.1542 (16)Å and 1.3501 (19) Å, respectively. The gadolinium bond valence sum of 2.90, calculated by the Brese & O'Keffe (1991) method, indicates that it is slightly underbonded in (I), whereas in [Y(biur)2(H2O)4].3Cl (Harrison, 2008), the yttrium cation was distinctly overbonded with a BVS of 3.34 (expected value = 3.00 in both cases).
The dihedral angle betwen the N1/C1/O1/N2 and N2/C2/O2/N3 fragments of the biuret molecule is 21.2 (2)°, which is far larger than the equivalent value of 5.06 (10)° in [Y(biur)2(H2O)4].3Cl (Harrison, 2008). The gadolinium cation in (I) deviates from the N1/C1/O1/N2 and N2/C2/O2/N3 mean planes by -0.834 (6)Å and 0.530 (6) Å, respectively, indicating that the six-membered chelate ring is non-planar.
The component species in (I) are linked by a dense array of N—H···O, N—H···Cl and O—H···Cl hydrogen bonds (Table 2) resulting in a three-dimensional network. Of note is the N—H···O hydrogen bond, which results in [100] chains of cations, linked by R22(8) loops (Bernstein et al., 1995), as also seen in the yttrium phase (Harrison, 2008).
For related rare-earth–biuret complexes, see: Haddad (1987 and 1988).