supplementary materials


HTML versionpdf versioncif file3d viewstructure factorssupplementary materialsCIF check reportsimilar papers Open access

hk2447 scheme

Acta Cryst. (2008). E64, m673-m674    [ doi:10.1107/S1600536808009021 ]

Aquadioxidobis(pentane-2,4-dionato)uranium(VI) pyrazine solvate

T. Kawasaki and T. Kitazawa

Abstract top

The asymmetric unit of the title compound, [U(C5H7O2)2O2(H2O)]·C4H4N2, contains one [UO2(acac)2(H2O)] (where acac is acetylacetonate) and two half-molecules of pyrazine. It exhibits a UO7 pentagonal-bipyramidal coordination geometry about the UVI atom, involving two bidentate acetylacetonate ions and one water molecule. The N atoms of the pyrazine molecules are not coordinated to the UVI atom, and are connected with the aqua O atom by hydrogen bonds. This results in a zigzag chain arrangement along the [10\overline{1}] direction.

Comment top

Actinide chemistry has strong relationship with the reprocessing of nuclear fuels and treatment of actinide wastes in the backend chemistry for the nuclear power plants which operate everyday. The fundamental investigation of the bonding and structure of uranium complexes provides important information on the field of backend chemistry. Various uranyl(VI) complexes with β-diketonate have been reported; examples are [UO2(acac)2(H2O)] (Alcock, & Flanders, 1987), [UO2(acac)2(py)] (Alcock et al., 1984; Alcock et al., 1987), [UO2(tta)2(H2O)](H2O)2(dibenzo-18, crown-6) (Kannan et al., 2001), [UO2(acac)2(dmf)] (Huuskonen et al., 2007), and [UO2(dbm)2(EtOH)] (Takao & Ikeda, 2008). We report herein the synthesis and crystal structure of a new uranyl(VI) acetyl- acetonate complex of formula [UO2(acac)2(H2O)](pz) (I) (where acac is acetylacetonate and pz is pyrazine).

The asymmetric unit of the title compound, (I), (Fig. 1), contains one [UO2(acac)2(H2O)] and two-halves of pyrazine molecules. The coordination geometry of the U1 atom has a UO7 pentagonal-bipyramidal coordination; two uranyl oxygen atoms (O1 and O2) at the axial positions, and the remaining five O atoms from the two chelating acac ligands (O3, O4, O5 and O6) and one H2O molecule (O7) in the equatorial plane (Table 1). The O1—U1—O2 angle is 178.98 (14) °. The deviations of the O atoms of the acac and of the H2O from the equatorial plane (O3, O4, O5, O6 and O7) are within 0.02 Å. The U1—Oacac bond lengths are longer than the U1—Ouranyl distances and are shorter than the U1—Oaqua distance. The U1—O7 [2.409 (4) Å] bond is shorter than the UVI—Oaqua [2.489 (8) Å] bond of [UO2(acac)2(H2O)] (Alcock, & Flanders, 1987), but similar to the UVI—Oaqua [2.396 (5) Å] bond of {[UO2(C9H4O6)- (H2O)].H2O} (Borkowski & Cahill, 2004) and the UVI—Oaqua [2.419 (5) Å] bond of [UO2(tta)2(H2O)](H2O)2(dibenzo-18,crown-6) (Kannan et al., 2001).

The nitrogen atoms of the pyrazine molecules are not coordinated to the U1, and are connected with O7 atom of the H2O in the [UO2(acac)2(H2O)] molecule by the hydrogen bonds (Table 2). This results in a zigzag chain arrangement of along the [1 0 - 1] direction (Fig. 2). The dihedral angle between the two pyrazine rings is 13.9 (3)°.

Related literature top

For related structures, see: Alcock et al. (1984, 1987); Alcock & Flanders (1987); Borkowski & Cahill (2004); Huuskonen et al. (2007); Kannan et al. (2001); Takao & Ikeda (2008).

Experimental top

To the acetonitrile solution (10 ml) containing UO2(NO3)2.6H2O (0.5 mmol) was added acetylacetone (3.0 mmol) and pyrazine (3.0 mmol) in acetonitrile (5 ml). After the solvent evaporated slowly at room temperature for a few days, orange crystals of (I) were obtained.

Refinement top

H atoms (for H2O) were located in difference syntheses and refined isotropically by applying restrains on O-H bonds [O-H = 0.852 (10) and 0.849 (10) Å; Uiso(H) = 0.062 (16) and 0.069 (18) Å2]. The remaining H atoms were positioned geometrically, with C-H = 0.93 Å (for CH) and 0.96 Å (for CH3) and constrained to ride on their parent atoms with Uiso(H) = xUeq(C), where x = 1.5 for CH3 H and x = 1.2 for CH H atoms.

Computing details top

Data collection: SMART (Bruker, 2001); cell refinement: SAINT (Bruker, 2001); data reduction: SAINT (Bruker, 2001); program(s) used to solve structure: SHELXS97 (Sheldrick, 2008); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008); molecular graphics: SHELXTL (Sheldrick, 2008) and CrystalMaker (CrystalMaker, 2007); software used to prepare material for publication: SHELXTL (Sheldrick, 2008).

Figures top
[Figure 1] Fig. 1. Molecular structure of (I). Displacement ellipsoids are drawn at the 50% probablity level. Hydrogen bonds are shown as dashed lines [symmetry codes: (i) -x + 1, -y + 2, -z; (ii) -x, -y + 2, -z + 1]. H atoms not involved in hydrogen bondings have been omitted for clarity.
[Figure 2] Fig. 2. Zigzag chain arragnement formed by O7 of the [UO2(acac)2(H2O)] molecules and the pyrazine molecules in (I). Dashed lines indicate the OH···N hydrogen bonds between neighboring O7 and the pyrazine molecules. H atoms not involved in hydrogen bondings have been omitted for clarity.
Aquadioxidobis(pentane-2,4-dionato)uranium(VI) pyrazine solvate top
Crystal data top
[U(C5H7O2)2O2(H2O)]·C4H4N2Z = 2
Mr = 566.35F000 = 532
Triclinic, P1Dx = 2.027 Mg m−3
Hall symbol: -P 1Mo Kα radiation
λ = 0.71073 Å
a = 8.186 (3) ÅCell parameters from 2961 reflections
b = 8.398 (3) Åθ = 2.4–28.2º
c = 13.663 (4) ŵ = 8.78 mm−1
α = 88.162 (7)ºT = 299 K
β = 82.111 (6)ºPlate, orange
γ = 86.130 (6)º0.22 × 0.14 × 0.06 mm
V = 928.0 (5) Å3
Data collection top
Bruker CCD area-detector
diffractometer		4526 independent reflections
Radiation source: fine-focus sealed tube3841 reflections with I > 2σ(I)
Monochromator: graphiteRint = 0.024
Detector resolution: 8.366 pixels mm-1θmax = 28.3º
T = 299 Kθmin = 1.5º
φ and ω scansh = −10→10
Absorption correction: multi-scan
(SADABS; Sheldrick, 1996)		k = −11→9
Tmin = 0.236, Tmax = 0.590l = −18→11
6928 measured reflections
Refinement top
Refinement on F2Secondary atom site location: difference Fourier map
Least-squares matrix: fullHydrogen site location: inferred from neighbouring sites
R[F2 > 2σ(F2)] = 0.031H atoms treated by a mixture of
independent and constrained refinement
wR(F2) = 0.078  w = 1/[σ2(Fo2) + (0.0402P)2 + 0.5065P]
where P = (Fo2 + 2Fc2)/3
S = 1.04(Δ/σ)max = 0.001
4526 reflectionsΔρmax = 1.63 e Å−3
229 parametersΔρmin = −1.27 e Å−3
2 restraintsExtinction correction: none
Primary atom site location: structure-invariant direct methods
Crystal data top
[U(C5H7O2)2O2(H2O)]·C4H4N2γ = 86.130 (6)º
Mr = 566.35V = 928.0 (5) Å3
Triclinic, P1Z = 2
a = 8.186 (3) ÅMo Kα
b = 8.398 (3) ŵ = 8.78 mm−1
c = 13.663 (4) ÅT = 299 K
α = 88.162 (7)º0.22 × 0.14 × 0.06 mm
β = 82.111 (6)º
Data collection top
Bruker CCD area-detector
diffractometer		4526 independent reflections
Absorption correction: multi-scan
(SADABS; Sheldrick, 1996)		3841 reflections with I > 2σ(I)
Tmin = 0.236, Tmax = 0.590Rint = 0.024
6928 measured reflections
Refinement top
R[F2 > 2σ(F2)] = 0.0312 restraints
wR(F2) = 0.078H atoms treated by a mixture of
independent and constrained refinement
S = 1.04Δρmax = 1.63 e Å−3
4526 reflectionsΔρmin = −1.27 e Å−3
229 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 > 2sigma(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
U10.259453 (17)0.495967 (19)0.247346 (9)0.03890 (8)
O10.3817 (5)0.4969 (5)0.1293 (3)0.0596 (10)
O20.1377 (5)0.4988 (5)0.3652 (3)0.0546 (9)
O30.0299 (5)0.5981 (5)0.1735 (3)0.0700 (11)
O40.1164 (4)0.2826 (4)0.2022 (3)0.0573 (9)
O50.4908 (5)0.5598 (5)0.3208 (3)0.0688 (11)
O60.4016 (4)0.2596 (4)0.2952 (2)0.0549 (8)
O70.2572 (4)0.7828 (4)0.2495 (2)0.0501 (8)
N10.4115 (6)0.9337 (6)0.0839 (3)0.0577 (12)
N20.0840 (6)0.9322 (6)0.4142 (3)0.0557 (11)
C1−0.2101 (7)0.6668 (8)0.0993 (5)0.0789 (19)
H1A−0.29140.70040.15340.118*
H1B−0.26370.62070.04970.118*
H1C−0.15310.75730.07130.118*
C2−0.0877 (7)0.5442 (8)0.1361 (4)0.0565 (14)
C3−0.1090 (8)0.3840 (8)0.1297 (5)0.0764 (19)
H3−0.19920.35580.10100.092*
C4−0.0086 (6)0.2633 (7)0.1619 (4)0.0547 (12)
C5−0.0468 (9)0.0931 (8)0.1488 (6)0.088 (2)
H5A0.04350.03990.10750.133*
H5B−0.14560.09150.11840.133*
H5C−0.06250.03930.21210.133*
C60.7166 (7)0.5944 (8)0.4048 (4)0.0721 (17)
H6A0.80710.61430.35430.108*
H6B0.75800.54150.46050.108*
H6C0.65910.69390.42490.108*
C70.5996 (6)0.4899 (8)0.3648 (4)0.0541 (14)
C80.6166 (8)0.3245 (9)0.3785 (5)0.0744 (18)
H80.69790.28330.41520.089*
C90.5220 (6)0.2191 (7)0.3416 (4)0.0547 (12)
C100.5580 (9)0.0434 (8)0.3557 (5)0.086 (2)
H10A0.4673−0.00080.39740.128*
H10B0.65690.02520.38600.128*
H10C0.5730−0.00680.29270.128*
C110.4593 (7)0.8497 (7)0.0033 (4)0.0535 (13)
H110.43480.74320.00300.064*
C120.4551 (8)1.0829 (8)0.0803 (4)0.0614 (15)
H120.42721.14460.13620.074*
C130.0714 (7)1.0896 (7)0.4270 (4)0.0569 (14)
H130.12061.15560.37710.068*
C140.0118 (7)0.8421 (7)0.4888 (4)0.0527 (12)
H140.01810.73170.48330.063*
H220.202 (6)0.846 (5)0.291 (3)0.069 (18)*
H210.284 (6)0.845 (5)0.200 (3)0.062 (16)*
Atomic displacement parameters (Å2) top
U11U22U33U12U13U23
U10.04099 (10)0.04129 (13)0.03434 (9)−0.00227 (7)−0.00502 (6)−0.00051 (7)
O10.069 (2)0.061 (3)0.0440 (18)−0.0096 (19)0.0121 (16)−0.0057 (17)
O20.058 (2)0.056 (2)0.0461 (17)−0.0055 (18)0.0052 (15)0.0023 (17)
O30.077 (3)0.050 (3)0.091 (3)−0.004 (2)−0.043 (2)0.007 (2)
O40.060 (2)0.052 (2)0.064 (2)−0.0073 (17)−0.0236 (16)0.0040 (18)
O50.058 (2)0.059 (3)0.097 (3)−0.0040 (19)−0.036 (2)0.000 (2)
O60.0554 (19)0.053 (2)0.0590 (19)0.0022 (17)−0.0185 (15)−0.0024 (17)
O70.058 (2)0.046 (2)0.0426 (17)0.0002 (17)0.0050 (15)−0.0020 (16)
N10.065 (3)0.054 (3)0.048 (2)0.004 (2)0.0087 (19)0.007 (2)
N20.064 (3)0.050 (3)0.047 (2)−0.004 (2)0.0117 (19)−0.004 (2)
C10.067 (4)0.082 (5)0.091 (4)0.008 (3)−0.031 (3)0.015 (4)
C20.050 (3)0.071 (4)0.049 (3)0.002 (3)−0.016 (2)0.007 (3)
C30.067 (4)0.067 (5)0.104 (5)−0.012 (3)−0.043 (3)0.009 (4)
C40.055 (3)0.056 (3)0.056 (3)−0.014 (2)−0.013 (2)0.002 (2)
C50.087 (4)0.060 (4)0.129 (6)−0.018 (4)−0.047 (4)−0.003 (4)
C60.052 (3)0.097 (5)0.072 (3)−0.011 (3)−0.020 (3)−0.013 (3)
C70.040 (2)0.080 (4)0.043 (2)−0.002 (3)−0.0084 (18)−0.007 (3)
C80.065 (3)0.073 (5)0.091 (4)0.008 (3)−0.036 (3)0.004 (4)
C90.044 (2)0.062 (4)0.056 (3)0.011 (2)−0.006 (2)0.000 (2)
C100.090 (5)0.065 (4)0.105 (5)0.016 (4)−0.036 (4)0.001 (4)
C110.067 (3)0.043 (3)0.048 (3)0.000 (2)−0.002 (2)−0.001 (2)
C120.087 (4)0.055 (4)0.037 (2)0.005 (3)0.006 (2)−0.007 (2)
C130.064 (3)0.055 (4)0.048 (3)−0.013 (3)0.008 (2)0.007 (2)
C140.062 (3)0.039 (3)0.055 (3)−0.004 (2)0.001 (2)−0.001 (2)
Geometric parameters (Å, °) top
U1—O11.777 (3)C4—C51.505 (8)
U1—O21.774 (3)C5—H5A0.9600
U1—O32.352 (4)C5—H5B0.9600
U1—O42.348 (4)C5—H5C0.9600
U1—O52.361 (4)C6—C71.507 (8)
U1—O62.353 (3)C6—H6A0.9600
U1—O72.409 (4)C6—H6B0.9600
O3—C21.265 (6)C6—H6C0.9600
O4—C41.249 (6)C7—C81.396 (9)
O5—C71.246 (6)C8—C91.366 (8)
O6—C91.266 (6)C8—H80.9300
O7—H210.86 (4)C9—C101.496 (8)
O7—H220.85 (4)C10—H10A0.9600
N1—C111.326 (7)C10—H10B0.9600
N1—C121.323 (8)C10—H10C0.9600
N2—C131.334 (8)C11—C12i1.381 (7)
N2—C141.344 (6)C11—H110.9300
C1—C21.511 (8)C12—C11i1.381 (7)
C1—H1A0.9600C12—H120.9300
C1—H1B0.9600C13—C14ii1.375 (8)
C1—H1C0.9600C13—H130.9300
C2—C31.376 (9)C14—C13ii1.375 (8)
C3—C41.361 (8)C14—H140.9300
C3—H30.9300
O1—U1—O2178.98 (14)O4—C4—C3124.6 (5)
O1—U1—O389.43 (18)O4—C4—C5116.1 (5)
O1—U1—O490.62 (17)C3—C4—C5119.3 (5)
O1—U1—O589.85 (18)C4—C5—H5A109.5
O1—U1—O691.40 (17)C4—C5—H5B109.5
O1—U1—O790.01 (16)H5A—C5—H5B109.5
O2—U1—O390.37 (17)C4—C5—H5C109.5
O2—U1—O490.26 (16)H5A—C5—H5C109.5
O2—U1—O589.75 (17)H5B—C5—H5C109.5
O2—U1—O689.35 (16)C7—C6—H6A109.5
O2—U1—O788.97 (15)C7—C6—H6B109.5
O3—U1—O470.89 (13)H6A—C6—H6B109.5
O3—U1—O5145.58 (15)C7—C6—H6C109.5
O3—U1—O6143.98 (14)H6A—C6—H6C109.5
O3—U1—O772.72 (13)H6B—C6—H6C109.5
O4—U1—O5143.53 (13)O5—C7—C8123.7 (5)
O4—U1—O673.10 (12)O5—C7—C6116.4 (6)
O4—U1—O7143.59 (13)C8—C7—C6119.9 (5)
O5—U1—O670.43 (13)C9—C8—C7124.5 (5)
O5—U1—O772.87 (13)C9—C8—H8117.7
O6—U1—O7143.27 (13)C7—C8—H8117.7
C2—O3—U1137.8 (4)O6—C9—C8124.2 (5)
C4—O4—U1137.9 (4)O6—C9—C10116.0 (5)
C7—O5—U1138.5 (4)C8—C9—C10119.9 (5)
C9—O6—U1138.2 (4)C9—C10—H10A109.5
U1—O7—H22129 (4)C9—C10—H10B109.5
U1—O7—H21127 (4)H10A—C10—H10B109.5
H22—O7—H21102 (5)C9—C10—H10C109.5
C12—N1—C11116.2 (4)H10A—C10—H10C109.5
C13—N2—C14116.4 (5)H10B—C10—H10C109.5
C2—C1—H1A109.5N1—C11—C12i121.4 (5)
C2—C1—H1B109.5N1—C11—H11119.3
H1A—C1—H1B109.5C12i—C11—H11119.3
C2—C1—H1C109.5N1—C12—C11i122.4 (5)
H1A—C1—H1C109.5N1—C12—H12118.8
H1B—C1—H1C109.5C11i—C12—H12118.8
O3—C2—C3123.5 (5)N2—C13—C14ii122.5 (5)
O3—C2—C1116.3 (6)N2—C13—H13118.8
C3—C2—C1120.2 (5)C14ii—C13—H13118.8
C4—C3—C2125.3 (5)N2—C14—C13ii121.1 (5)
C4—C3—H3117.3N2—C14—H14119.5
C2—C3—H3117.3C13ii—C14—H14119.5
Symmetry codes: (i) −x+1, −y+2, −z; (ii) −x, −y+2, −z+1.
Hydrogen-bond geometry (Å, °) top
D—H···AD—HH···AD···AD—H···A
O7—H21···N10.86 (4)1.94 (2)2.752 (5)160 (5)
O7—H22···N20.85 (4)1.96 (2)2.778 (6)161 (5)
Table 1
Selected geometric parameters (Å, °) top
U1—O11.777 (3)U1—O52.361 (4)
U1—O21.774 (3)U1—O62.353 (3)
U1—O32.352 (4)U1—O72.409 (4)
U1—O42.348 (4)
O1—U1—O2178.98 (14)O3—U1—O470.89 (13)
O1—U1—O389.43 (18)O3—U1—O5145.58 (15)
O1—U1—O490.62 (17)O3—U1—O6143.98 (14)
O1—U1—O589.85 (18)O3—U1—O772.72 (13)
O1—U1—O691.40 (17)O4—U1—O5143.53 (13)
O1—U1—O790.01 (16)O4—U1—O673.10 (12)
O2—U1—O390.37 (17)O4—U1—O7143.59 (13)
O2—U1—O490.26 (16)O5—U1—O670.43 (13)
O2—U1—O589.75 (17)O5—U1—O772.87 (13)
O2—U1—O689.35 (16)O6—U1—O7143.27 (13)
O2—U1—O788.97 (15)
Table 2
Hydrogen-bond geometry (Å, °) top
D—H···AD—HH···AD···AD—H···A
O7—H21···N10.86 (4)1.94 (2)2.752 (5)160 (5)
O7—H22···N20.85 (4)1.96 (2)2.778 (6)161 (5)
Acknowledgements top

We will not attach the acknowledgements.

references
References top

Alcock, N. W. & Flanders, D. J. (1987). Acta Cryst. C43, 1480–1483.

Alcock, N. W., Flanders, D. J. & Brown, D. (1984). J. Chem. Soc., Dalton Trans. pp. 679–681.

Alcock, N. W., Flanders, D. J., Pennington, M. & Brown, D. (1987). Acta Cryst. C43, 1476–1480.

Borkowski, L. A. & Cahill, C. L. (2004). Acta Cryst. E60, m198–m200.

Bruker (2001). SMART and SAINT. Bruker AXS Inc., Madison, Wisconsin, USA.

CrystalMaker (2007). CrystalMaker. CrystalMaker Software Ltd., Yarnton, Oxfordshire, England.

Huuskonen, J., Raatikainen, K. & Rissanen, K. (2007). Acta Cryst. E63, m413–m414.

Kannan, S., Raj, S. S. & Fun, H.-K. (2001). Polyhedron, 20, 2145–2150.

Sheldrick, G. M. (1996). SADABS. University of Göttingen, Germany.

Sheldrick, G. M. (2008). Acta Cryst. A64, 112–122.

Takao, K. & Ikeda, Y. (2008). Acta Cryst. E64, m219–m220.