metal-organic compounds\(\def\hfill{\hskip 5em}\def\hfil{\hskip 3em}\def\eqno#1{\hfil {#1}}\)

Journal logoCRYSTALLOGRAPHIC
COMMUNICATIONS
ISSN: 2056-9890

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

(Received 27 March 2008; accepted 31 March 2008; online 2 April 2008)

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 site symmetry 2.

Related literature

For related structures, see: Haddad (1987[Haddad, S. F. (1987). Acta Cryst. C43, 1882-1885.], 1988[Haddad, S. F. (1988). Acta Cryst. C44, 815-818.]); Harrison (2008[Harrison, W. T. A. (2008). Acta Cryst. E64, m619.]). For related literature, see: Bernstein et al. (1995[Bernstein, J., Davis, R. E., Shimoni, L. & Chang, N.-L. (1995). Angew. Chem. Int. Ed. Engl. 34, 1555-1573.]). For valence-sum calculations, see: Brese & O'Keeffe (1991[Brese, N. E. & O'Keeffe, M. (1991). Acta Cryst. B47, 192-197.]).

[Scheme 1]

Experimental

Crystal data
  • [Gd(C2H5N3O2)2(H2O)4]Cl3

  • Mr = 541.84

  • Monoclinic, C 2/c

  • a = 7.6501 (3) Å

  • b = 13.2164 (5) Å

  • c = 17.4557 (6) Å

  • β = 100.961 (1)°

  • V = 1732.69 (11) Å3

  • Z = 4

  • Mo Kα radiation

  • μ = 4.33 mm−1

  • T = 293 (2) K

  • 0.47 × 0.34 × 0.06 mm

Data collection
  • Bruker SMART1000 CCD diffractometer

  • Absorption correction: multi-scan (SADABS; Bruker, 1999[Bruker (1999). SMART, SAINT and SADABS. Bruker AXS Inc., Madison, Wisconsin, USA.]) Tmin = 0.235, Tmax = 0.781

  • 8649 measured reflections

  • 3134 independent reflections

  • 2902 reflections with I > 2σ(I)

  • Rint = 0.025

Refinement
  • R[F2 > 2σ(F2)] = 0.033

  • wR(F2) = 0.088

  • S = 1.06

  • 3134 reflections

  • 101 parameters

  • H-atom parameters constrained

  • Δρmax = 2.99 e Å−3

  • Δρmin = −3.45 e Å−3

Table 1
Selected bond lengths (Å)

Gd1—O1 2.350 (2)
Gd1—O2 2.375 (2)
Gd1—O4 2.407 (3)
Gd1—O3 2.414 (2)

Table 2
Hydrogen-bond geometry (Å, °)

D—H⋯A D—H H⋯A DA 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+{\script{3\over 2}}]; (ii) [x+{\script{1\over 2}}, y-{\script{1\over 2}}, z]; (iii) [x-{\script{1\over 2}}, y-{\script{1\over 2}}, z]; (iv) -x, -y, -z+1; (v) [-x-{\script{1\over 2}}, -y+{\script{1\over 2}}, -z+1]; (vi) x-1, y, z.

Data collection: SMART (Bruker, 1999[Bruker (1999). SMART, SAINT and SADABS. Bruker AXS Inc., Madison, Wisconsin, USA.]); cell refinement: SAINT (Bruker, 1999[Bruker (1999). SMART, SAINT and SADABS. Bruker AXS Inc., Madison, Wisconsin, USA.]); data reduction: SAINT; program(s) used to solve structure: SHELXS97 (Sheldrick, 2008[Sheldrick, G. M. (2008). Acta Cryst. A64, 112-122.]); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008[Sheldrick, G. M. (2008). Acta Cryst. A64, 112-122.]); molecular graphics: ORTEP-3 (Farrugia, 1997[Farrugia, L. J. (1997). J. Appl. Cryst. 30, 565.]); software used to prepare material for publication: SHELXL97.

Supporting information


Comment top

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).

Related literature top

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 top

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.

Refinement top

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.

Computing details top

Data collection: SMART (Bruker, 1999); cell refinement: 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).

Figures top
[Figure 1] 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.
Tetraaquabis(biuret-κ2O,O')gadolinium(III) trichloride top
Crystal data top
[Gd(C2H5N3O2)2(H2O)4]Cl3F(000) = 1052
Mr = 541.84Dx = 2.077 Mg m3
Monoclinic, C2/cMo Kα radiation, λ = 0.71073 Å
Hall symbol: -C 2ycCell parameters from 6423 reflections
a = 7.6501 (3) Åθ = 2.4–32.5°
b = 13.2164 (5) ŵ = 4.33 mm1
c = 17.4557 (6) ÅT = 293 K
β = 100.961 (1)°Slab, colourless
V = 1732.69 (11) Å30.47 × 0.34 × 0.06 mm
Z = 4
Data collection top
Bruker SMART1000 CCD
diffractometer
3134 independent reflections
Radiation source: fine-focus sealed tube2902 reflections with I > 2σ(I)
Graphite monochromatorRint = 0.025
ω scansθmax = 32.5°, θmin = 2.4°
Absorption correction: multi-scan
(SADABS; Bruker, 1999)
h = 119
Tmin = 0.235, Tmax = 0.781k = 1918
8649 measured reflectionsl = 1926
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)] = 0.033Hydrogen site location: difmap (O-H) and geom (N-H)
wR(F2) = 0.088H-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 parametersΔρmax = 2.99 e Å3
0 restraintsΔρmin = 3.45 e Å3
Crystal data top
[Gd(C2H5N3O2)2(H2O)4]Cl3V = 1732.69 (11) Å3
Mr = 541.84Z = 4
Monoclinic, C2/cMo Kα radiation
a = 7.6501 (3) ŵ = 4.33 mm1
b = 13.2164 (5) ÅT = 293 K
c = 17.4557 (6) Å0.47 × 0.34 × 0.06 mm
β = 100.961 (1)°
Data collection top
Bruker SMART1000 CCD
diffractometer
3134 independent reflections
Absorption correction: multi-scan
(SADABS; Bruker, 1999)
2902 reflections with I > 2σ(I)
Tmin = 0.235, Tmax = 0.781Rint = 0.025
8649 measured reflections
Refinement top
R[F2 > 2σ(F2)] = 0.0330 restraints
wR(F2) = 0.088H-atom parameters constrained
S = 1.06Δρmax = 2.99 e Å3
3134 reflectionsΔρmin = 3.45 e Å3
101 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
xyzUiso*/Ueq
Gd10.00000.106486 (13)0.75000.02252 (7)
Cl10.04157 (10)0.33393 (7)0.50790 (4)0.03672 (16)
Cl20.50000.30307 (10)0.75000.0389 (2)
O10.2531 (3)0.02702 (18)0.71963 (13)0.0310 (4)
O20.0822 (3)0.01130 (17)0.63327 (12)0.0305 (4)
N10.4595 (4)0.0112 (3)0.64845 (18)0.0434 (7)
H10.54230.01690.68200.052*
H20.48450.03870.60720.052*
N20.1720 (3)0.0598 (2)0.60404 (15)0.0295 (5)
H30.21190.09770.57120.035*
N30.1037 (4)0.1127 (2)0.5433 (2)0.0371 (6)
H40.21810.10980.53370.044*
H50.04970.15520.51860.044*
C10.2950 (4)0.0121 (2)0.66032 (16)0.0269 (5)
C20.0103 (4)0.0513 (2)0.59616 (16)0.0265 (5)
O30.2462 (3)0.18787 (18)0.66543 (13)0.0360 (5)
H60.28050.17480.61990.043*
H70.32440.21600.68100.043*
O40.1191 (3)0.2294 (2)0.67206 (16)0.0502 (7)
H80.08330.25340.63270.060*
H90.21810.25070.67430.060*
Atomic displacement parameters (Å2) top
U11U22U33U12U13U23
Gd10.01907 (9)0.02952 (10)0.01740 (9)0.0000.00047 (6)0.000
Cl10.0337 (3)0.0470 (4)0.0268 (3)0.0011 (3)0.0007 (2)0.0067 (3)
Cl20.0301 (4)0.0496 (6)0.0377 (5)0.0000.0081 (4)0.000
O10.0217 (8)0.0441 (12)0.0257 (9)0.0024 (8)0.0006 (7)0.0071 (8)
O20.0251 (9)0.0359 (10)0.0275 (9)0.0038 (8)0.0024 (7)0.0077 (8)
N10.0233 (11)0.073 (2)0.0345 (14)0.0075 (12)0.0071 (10)0.0178 (14)
N20.0240 (10)0.0363 (12)0.0269 (11)0.0004 (9)0.0018 (8)0.0083 (9)
N30.0297 (13)0.0416 (15)0.0364 (15)0.0020 (9)0.0025 (11)0.0147 (11)
C10.0227 (11)0.0322 (12)0.0241 (11)0.0010 (9)0.0005 (9)0.0008 (9)
C20.0247 (11)0.0296 (12)0.0231 (11)0.0000 (9)0.0010 (9)0.0016 (9)
O30.0337 (10)0.0484 (13)0.0228 (9)0.0135 (9)0.0027 (7)0.0022 (9)
O40.0384 (13)0.0637 (17)0.0423 (14)0.0157 (12)0.0084 (10)0.0257 (12)
Geometric parameters (Å, º) top
Gd1—O1i2.350 (2)N1—H20.8600
Gd1—O12.350 (2)N2—C11.377 (4)
Gd1—O22.375 (2)N2—C21.380 (4)
Gd1—O2i2.375 (2)N2—H30.8600
Gd1—O4i2.407 (3)N3—C21.330 (4)
Gd1—O42.407 (3)N3—H40.8600
Gd1—O3i2.414 (2)N3—H50.8600
Gd1—O32.414 (2)O3—H60.8067
O1—C11.253 (4)O3—H70.7949
O2—C21.242 (3)O4—H80.7597
N1—C11.314 (4)O4—H90.8018
N1—H10.8600
O1i—Gd1—O1126.90 (12)O4—Gd1—O371.88 (8)
O1i—Gd1—O282.06 (8)O3i—Gd1—O3127.08 (12)
O1—Gd1—O270.41 (7)C1—O1—Gd1136.27 (18)
O1i—Gd1—O2i70.41 (7)C2—O2—Gd1136.83 (18)
O1—Gd1—O2i82.06 (8)C1—N1—H1120.0
O2—Gd1—O2i116.04 (11)C1—N1—H2120.0
O1i—Gd1—O4i75.96 (10)H1—N1—H2120.0
O1—Gd1—O4i147.78 (8)C1—N2—C2125.1 (3)
O2—Gd1—O4i140.85 (7)C1—N2—H3117.4
O2i—Gd1—O4i86.53 (9)C2—N2—H3117.4
O1i—Gd1—O4147.78 (8)C2—N3—H4120.0
O1—Gd1—O475.96 (10)C2—N3—H5120.0
O2—Gd1—O486.53 (9)H4—N3—H5120.0
O2i—Gd1—O4140.85 (8)O1—C1—N1122.0 (3)
O4i—Gd1—O495.10 (17)O1—C1—N2122.1 (3)
O1i—Gd1—O3i129.93 (8)N1—C1—N2115.9 (3)
O1—Gd1—O3i75.91 (8)O2—C2—N3122.4 (3)
O2—Gd1—O3i144.00 (8)O2—C2—N2122.7 (2)
O2i—Gd1—O3i70.30 (7)N3—C2—N2114.8 (3)
O4i—Gd1—O3i71.88 (9)Gd1—O3—H6125.2
O4—Gd1—O3i73.11 (8)Gd1—O3—H7123.3
O1i—Gd1—O375.91 (8)H6—O3—H7108.2
O1—Gd1—O3129.93 (8)Gd1—O4—H8133.1
O2—Gd1—O370.30 (7)Gd1—O4—H9131.7
O2i—Gd1—O3144.00 (8)H8—O4—H994.1
O4i—Gd1—O373.11 (8)
O1i—Gd1—O1—C181.6 (3)O4—Gd1—O2—C285.5 (3)
O2—Gd1—O1—C118.4 (3)O3i—Gd1—O2—C230.9 (4)
O2i—Gd1—O1—C1139.7 (3)O3—Gd1—O2—C2157.5 (3)
O4i—Gd1—O1—C1149.9 (3)Gd1—O1—C1—N1149.2 (3)
O4—Gd1—O1—C172.9 (3)Gd1—O1—C1—N231.6 (5)
O3i—Gd1—O1—C1148.7 (3)C2—N2—C1—O115.1 (5)
O3—Gd1—O1—C121.8 (3)C2—N2—C1—N1165.6 (3)
O1i—Gd1—O2—C2124.7 (3)Gd1—O2—C2—N3161.3 (2)
O1—Gd1—O2—C29.2 (3)Gd1—O2—C2—N221.7 (5)
O2i—Gd1—O2—C261.1 (3)C1—N2—C2—O29.9 (5)
O4i—Gd1—O2—C2179.3 (3)C1—N2—C2—N3172.8 (3)
Symmetry code: (i) x, y, z+3/2.
Hydrogen-bond geometry (Å, º) top
D—H···AD—HH···AD···AD—H···A
N1—H1···O1ii0.862.102.910 (4)157
N1—H2···Cl1iii0.862.403.194 (3)154
N2—H3···Cl1iii0.862.533.315 (3)153
N3—H4···Cl1iv0.862.543.363 (3)161
N3—H5···Cl1v0.862.533.311 (3)151
O3—H6···Cl1vi0.812.393.163 (2)162
O3—H7···Cl2vii0.792.283.059 (2)167
O4—H8···Cl10.762.453.208 (2)178
O4—H9···Cl20.802.413.127 (2)150
Symmetry codes: (ii) x+1, y, z+3/2; (iii) x+1/2, y1/2, z; (iv) x1/2, y1/2, z; (v) x, y, z+1; (vi) x1/2, y+1/2, z+1; (vii) x1, y, z.

Experimental details

Crystal data
Chemical formula[Gd(C2H5N3O2)2(H2O)4]Cl3
Mr541.84
Crystal system, space groupMonoclinic, C2/c
Temperature (K)293
a, b, c (Å)7.6501 (3), 13.2164 (5), 17.4557 (6)
β (°) 100.961 (1)
V3)1732.69 (11)
Z4
Radiation typeMo Kα
µ (mm1)4.33
Crystal size (mm)0.47 × 0.34 × 0.06
Data collection
DiffractometerBruker SMART1000 CCD
diffractometer
Absorption correctionMulti-scan
(SADABS; Bruker, 1999)
Tmin, Tmax0.235, 0.781
No. of measured, independent and
observed [I > 2σ(I)] reflections
8649, 3134, 2902
Rint0.025
(sin θ/λ)max1)0.755
Refinement
R[F2 > 2σ(F2)], wR(F2), S 0.033, 0.088, 1.06
No. of reflections3134
No. of parameters101
H-atom treatmentH-atom parameters constrained
Δρmax, Δρmin (e Å3)2.99, 3.45

Computer programs: SMART (Bruker, 1999), SAINT (Bruker, 1999), SHELXS97 (Sheldrick, 2008), SHELXL97 (Sheldrick, 2008), ORTEP-3 (Farrugia, 1997).

Selected bond lengths (Å) top
Gd1—O12.350 (2)Gd1—O42.407 (3)
Gd1—O22.375 (2)Gd1—O32.414 (2)
Hydrogen-bond geometry (Å, º) top
D—H···AD—HH···AD···AD—H···A
N1—H1···O1i0.862.102.910 (4)157
N1—H2···Cl1ii0.862.403.194 (3)154
N2—H3···Cl1ii0.862.533.315 (3)153
N3—H4···Cl1iii0.862.543.363 (3)161
N3—H5···Cl1iv0.862.533.311 (3)151
O3—H6···Cl1v0.812.393.163 (2)162
O3—H7···Cl2vi0.792.283.059 (2)167
O4—H8···Cl10.762.453.208 (2)178
O4—H9···Cl20.802.413.127 (2)150
Symmetry codes: (i) x+1, y, z+3/2; (ii) x+1/2, y1/2, z; (iii) x1/2, y1/2, z; (iv) x, y, z+1; (v) x1/2, y+1/2, z+1; (vi) x1, y, z.
 

References

First citationBernstein, 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
First citationBrese, N. E. & O'Keeffe, M. (1991). Acta Cryst. B47, 192–197.  CrossRef CAS Web of Science IUCr Journals Google Scholar
First citationBruker (1999). SMART, SAINT and SADABS. Bruker AXS Inc., Madison, Wisconsin, USA.  Google Scholar
First citationFarrugia, L. J. (1997). J. Appl. Cryst. 30, 565.  CrossRef IUCr Journals Google Scholar
First citationHaddad, S. F. (1987). Acta Cryst. C43, 1882–1885.  CSD CrossRef CAS IUCr Journals Google Scholar
First citationHaddad, S. F. (1988). Acta Cryst. C44, 815–818.  CSD CrossRef CAS Web of Science IUCr Journals Google Scholar
First citationHarrison, W. T. A. (2008). Acta Cryst. E64, m619.  Web of Science CSD CrossRef IUCr Journals Google Scholar
First citationSheldrick, 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.

Journal logoCRYSTALLOGRAPHIC
COMMUNICATIONS
ISSN: 2056-9890
Follow Acta Cryst. E
Sign up for e-alerts
Follow Acta Cryst. on Twitter
Follow us on facebook
Sign up for RSS feeds