Bis(μ-pyridazine-3-carboxyl-ato-κO:O')bis-[aqua-dioxido(pyridazine-3-carboxyl-ato-κN,O)uranium(VI)] dihydrate.

The structure of the binuclear title complex, [U(2)(C(5)H(3)N(2)O(2))(4)O(4)(H(2)O)(2)]·2H(2)O, is composed of centrosymmetric dimers in which each UO(2) (2+) ion is coordinated by two ligand mol-ecules. One donates its N,O-bonding group and the other donates both carboxyl-ate O atoms. Each of the latter bridges adjacent uranyl ions. The coordination environment of the metal center is a distorted penta-gonal bipyramid. The dimers are inter-connected by O-H⋯O hydrogen bonds between coordinated and uncoordinated water mol-ecules and carboxyl-ate O atoms. An intra-molecular O-H⋯N inter-action is also present.

Related literature

For the crystal structure of pyridazine–3–carboxylic acid hydro­chloride, see: Gryz et al. (2003 ▶). For centrosymmetric dimeric mol­ecules with a different bridging mode for the title ligand to calcium(II), see: Starosta & Leciejewicz (2007 ▶). For bond distances and angles in uranyl complexes with carboxyl­ate ligands, see: Leciejewicz et al. (1995 ▶).

Experimental

Crystal data

[U2(C5H3N2O2)4O4(H2O)2]·2H2O

M = 1104.50

Monoclinic,

a = 25.660 (5) Å

b = 6.8330 (14) Å

c = 16.673 (3) Å

β = 96.73 (3)°

V = 2903.2 (10) Å3

Z = 4

Mo Kα radiation

μ = 11.23 mm−1

T = 293 (2) K

0.19 × 0.12 × 0.07 mm

Data collection

Kuma KM-4 four-circle diffractometer

Absorption correction: analytical (CrysAlis RED; Oxford Diffraction, 2008 ▶) T min = 0.234, T max = 0.470

4406 measured reflections

4266 independent reflections

2746 reflections with I > 2σ(I)

R int = 0.025

3 standard reflections every 200 reflections intensity decay: 1.0%

Refinement

R[F 2 > 2σ(F 2)] = 0.043

wR(F 2) = 0.127

S = 1.01

4266 reflections

220 parameters

5 restraints

H atoms treated by a mixture of independent and constrained refinement

Δρmax = 2.83 e Å−3

Δρmin = −4.65 e Å−3

Data collection: KM-4 Software (Kuma, 1996 ▶); cell refinement: KM-4 Software; data reduction: DATAPROC (Kuma, 2001 ▶); program(s) used to solve structure: SHELXS97 (Sheldrick, 2008 ▶); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008 ▶); molecular graphics: SHELXTL (Sheldrick, 2008 ▶); software used to prepare material for publication: SHELXTL.

Crystal structure: contains datablocks I, global. DOI: 10.1107/S1600536808042219/rk2117sup1.cif

Structure factors: contains datablocks I. DOI: 10.1107/S1600536808042219/rk2117Isup2.hkl

Additional supplementary materials: crystallographic information; 3D view; checkCIF report

[U2(C5H3N2O2)4O4(H2O)2]·2H2O	F(000) = 2032
Mr = 1104.50	Dx = 2.527 Mg m−3
Monoclinic, C2/c	Mo Kα radiation, λ = 0.71073 Å
Hall symbol: -C 2yc	Cell parameters from 25 reflections
a = 25.660 (5) Å	θ = 6–15°
b = 6.8330 (14) Å	µ = 11.23 mm−1
c = 16.673 (3) Å	T = 293 K
β = 96.73 (3)°	Block, light green
V = 2903.2 (10) Å3	0.19 × 0.12 × 0.07 mm
Z = 4

Kuma KM-4 four-circle diffractometer	2746 reflections with I > 2σ(I)
Radiation source: Fine–focus sealed tube	Rint = 0.025
Graphite	θmax = 30.1°, θmin = 1.6°
ω/2θ profile scans	h = −36→35
Absorption correction: analytical (CrysAlis RED; Oxford Diffraction, 2008)	k = −9→0
Tmin = 0.234, Tmax = 0.470	l = 0→23
4406 measured reflections	3 standard reflections every 200 reflections
4266 independent reflections	intensity decay: 1.0%

Refinement on F2	Primary atom site location: Direct
Least-squares matrix: Full	Secondary atom site location: Difmap
R[F2 > 2σ(F2)] = 0.043	Hydrogen site location: Geom
wR(F2) = 0.127	H atoms treated by a mixture of independent and constrained refinement
S = 1.01	w = 1/[σ2(Fo2) + (0.0893P)2], where P = (Fo2 + 2Fc2)/3
4266 reflections	(Δ/σ)max < 0.001
220 parameters	Δρmax = 2.83 e Å−3
5 restraints	Δρmin = −4.65 e Å−3

Geometry. All s.u.'s (except the s.u. in the dihedral angle between two l.s. planes) are estimated using the full covariance matrix. The cell s.u.'s are taken into account individually in the estimation of s.u.'s in distances, angles and torsion angles; correlations between s.u.'s in cell parameters are only used when they are defined by crystal symmetry. An approximate (isotropic) treatment of cell s.u.'s is used for estimating s.u.'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
U1	0.388813 (9)	0.70410 (6)	0.214716 (15)	0.02772 (11)
O11	0.4687 (2)	0.7142 (12)	0.1613 (4)	0.0436 (16)
O21	0.3379 (2)	0.7086 (11)	0.3224 (3)	0.0425 (16)
C14	0.5457 (4)	0.7835 (16)	−0.0802 (6)	0.044 (2)
H14	0.5740	0.8037	−0.1092	0.052*
C16	0.5070 (3)	0.7471 (11)	0.0398 (5)	0.0267 (16)
O12	0.5529 (2)	0.7589 (12)	0.1677 (4)	0.0483 (19)
N21	0.2881 (3)	0.6906 (12)	0.1781 (4)	0.0365 (17)
N11	0.4595 (3)	0.7245 (12)	−0.0016 (4)	0.0345 (15)
C26	0.2583 (3)	0.6998 (13)	0.2373 (5)	0.0289 (15)
N12	0.4535 (3)	0.7342 (14)	−0.0813 (4)	0.0423 (19)
O1	0.3944 (2)	0.4495 (11)	0.2272 (4)	0.0420 (15)
C15	0.5519 (3)	0.7755 (15)	0.0024 (5)	0.0380 (19)
H15	0.5847	0.7884	0.0321	0.046*
C17	0.5096 (3)	0.7400 (12)	0.1300 (5)	0.0274 (16)
C13	0.4960 (5)	0.7605 (15)	−0.1178 (5)	0.046 (2)
H13	0.4916	0.7636	−0.1739	0.056*
O3	0.3712 (2)	0.6478 (13)	0.0725 (4)	0.0480 (19)
H32	0.361 (5)	0.537 (8)	0.060 (8)	0.072*
H31	0.398 (3)	0.655 (19)	0.050 (7)	0.072*
O22	0.2641 (2)	0.7074 (12)	0.3803 (4)	0.0478 (17)
O2	0.3827 (3)	0.9573 (12)	0.1990 (4)	0.0501 (17)
N22	0.2650 (3)	0.6893 (14)	0.0999 (4)	0.046 (2)
C27	0.2882 (3)	0.7068 (14)	0.3202 (5)	0.0313 (15)
C25	0.2035 (3)	0.7050 (14)	0.2253 (6)	0.0371 (18)
H25	0.1833	0.7094	0.2681	0.045*
C23	0.2131 (4)	0.6890 (16)	0.0858 (6)	0.045 (2)
H23	0.1976	0.6786	0.0327	0.054*
C24	0.1812 (3)	0.7034 (18)	0.1457 (7)	0.051 (3)
H24	0.1450	0.7118	0.1331	0.061*
O4	0.3251 (3)	0.6999 (15)	0.5313 (5)	0.058 (2)
H42	0.311 (5)	0.75 (2)	0.567 (5)	0.086*
H41	0.306 (5)	0.71 (2)	0.488 (4)	0.086*

	U11	U22	U33	U12	U13	U23
U1	0.01643 (13)	0.04731 (19)	0.02056 (14)	0.00034 (12)	0.00697 (8)	0.00059 (13)
O11	0.022 (3)	0.087 (5)	0.023 (3)	−0.010 (3)	0.007 (2)	−0.006 (3)
O21	0.027 (3)	0.082 (5)	0.020 (2)	−0.001 (3)	0.010 (2)	0.001 (3)
C14	0.048 (5)	0.054 (5)	0.033 (4)	−0.009 (4)	0.025 (4)	−0.002 (4)
C16	0.024 (3)	0.033 (5)	0.025 (3)	0.001 (2)	0.007 (3)	−0.003 (3)
O12	0.022 (3)	0.100 (6)	0.024 (3)	0.000 (3)	0.002 (2)	0.012 (3)
N21	0.021 (3)	0.065 (5)	0.025 (3)	0.001 (3)	0.008 (2)	0.003 (3)
N11	0.029 (3)	0.054 (5)	0.021 (3)	−0.002 (3)	0.005 (2)	0.002 (3)
C26	0.019 (3)	0.040 (4)	0.029 (3)	0.004 (3)	0.008 (2)	0.004 (3)
N12	0.045 (4)	0.060 (6)	0.021 (3)	−0.003 (4)	0.002 (3)	−0.003 (3)
O1	0.039 (3)	0.049 (4)	0.040 (3)	0.003 (3)	0.014 (3)	0.006 (3)
C15	0.026 (4)	0.060 (6)	0.030 (4)	−0.002 (4)	0.013 (3)	0.005 (4)
C17	0.023 (3)	0.038 (5)	0.023 (3)	0.005 (3)	0.009 (3)	0.005 (3)
C13	0.064 (6)	0.056 (7)	0.021 (4)	−0.007 (5)	0.010 (4)	0.000 (4)
O3	0.021 (3)	0.094 (6)	0.030 (3)	−0.003 (3)	0.009 (2)	0.000 (3)
O22	0.030 (3)	0.088 (5)	0.027 (3)	0.010 (3)	0.015 (2)	0.002 (3)
O2	0.057 (4)	0.047 (4)	0.048 (4)	−0.003 (3)	0.014 (3)	0.006 (3)
N22	0.027 (3)	0.088 (7)	0.024 (3)	0.001 (3)	0.003 (3)	0.005 (4)
C27	0.022 (3)	0.041 (4)	0.033 (4)	0.007 (3)	0.011 (3)	0.006 (4)
C25	0.021 (3)	0.046 (5)	0.046 (5)	−0.003 (3)	0.013 (3)	0.004 (4)
C23	0.032 (4)	0.069 (7)	0.034 (4)	0.000 (4)	−0.004 (3)	0.010 (4)
C24	0.014 (3)	0.074 (7)	0.064 (7)	0.000 (4)	−0.003 (3)	0.010 (6)
O4	0.041 (4)	0.100 (7)	0.033 (3)	0.012 (4)	0.010 (3)	0.008 (4)

U1—O2	1.754 (8)	N21—N22	1.367 (10)
U1—O1	1.756 (8)	N11—N12	1.321 (10)
U1—O11	2.331 (6)	C26—C25	1.399 (10)
U1—O21	2.342 (5)	C26—C27	1.501 (11)
U1—O12i	2.352 (6)	N12—C13	1.322 (13)
U1—O3	2.393 (6)	C15—H15	0.9300
U1—N21	2.588 (7)	C13—H13	0.9300
O11—C17	1.236 (9)	O3—H32	0.82 (6)
O21—C27	1.272 (9)	O3—H31	0.82 (9)
C14—C13	1.362 (15)	O22—C27	1.237 (9)
C14—C15	1.369 (12)	N22—C23	1.326 (11)
C14—H14	0.9300	C25—C24	1.382 (15)
C16—N11	1.338 (10)	C25—H25	0.9300
C16—C15	1.385 (10)	C23—C24	1.368 (15)
C16—C17	1.500 (11)	C23—H23	0.9300
O12—C17	1.218 (9)	C24—H24	0.9300
O12—U1i	2.352 (6)	O4—H42	0.81 (11)
N21—C26	1.317 (9)	O4—H41	0.83 (8)
O2—U1—O1	178.2 (3)	N22—N21—U1	122.2 (5)
O2—U1—O11	88.9 (3)	N12—N11—C16	120.3 (7)
O1—U1—O11	90.7 (3)	N21—C26—C25	123.8 (8)
O2—U1—O21	93.1 (3)	N21—C26—C27	114.4 (6)
O1—U1—O21	88.1 (3)	C25—C26—C27	121.8 (7)
O11—U1—O21	152.6 (2)	N11—N12—C13	117.6 (8)
O2—U1—O12i	90.3 (3)	C14—C15—C16	117.0 (8)
O1—U1—O12i	91.4 (3)	C14—C15—H15	121.5
O11—U1—O12i	79.1 (2)	C16—C15—H15	121.5
O21—U1—O12i	73.5 (2)	O12—C17—O11	124.4 (7)
O2—U1—O3	90.4 (3)	O12—C17—C16	116.3 (7)
O1—U1—O3	87.8 (3)	O11—C17—C16	119.2 (7)
O11—U1—O3	72.4 (2)	N12—C13—C14	125.6 (8)
O21—U1—O3	134.8 (2)	N12—C13—H13	117.2
O12i—U1—O3	151.5 (2)	C14—C13—H13	117.2
O2—U1—N21	86.0 (3)	U1—O3—H32	115 (9)
O1—U1—N21	93.3 (3)	U1—O3—H31	112 (9)
O11—U1—N21	144.2 (2)	H32—O3—H31	101 (10)
O21—U1—N21	63.2 (2)	C23—N22—N21	118.8 (7)
O12i—U1—N21	136.3 (2)	O22—C27—O21	124.7 (8)
O3—U1—N21	72.1 (2)	O22—C27—C26	119.8 (7)
C17—O11—U1	173.0 (7)	O21—C27—C26	115.4 (6)
C27—O21—U1	128.7 (5)	C24—C25—C26	115.6 (8)
C13—C14—C15	116.8 (8)	C24—C25—H25	122.2
C13—C14—H14	121.6	C26—C25—H25	122.2
C15—C14—H14	121.6	N22—C23—C24	123.1 (9)
N11—C16—C15	122.6 (8)	N22—C23—H23	118.5
N11—C16—C17	116.3 (7)	C24—C23—H23	118.5
C15—C16—C17	121.0 (7)	C23—C24—C25	119.1 (8)
C17—O12—U1i	150.0 (6)	C23—C24—H24	120.4
C26—N21—N22	119.4 (7)	C25—C24—H24	120.4
C26—N21—U1	118.2 (5)	H42—O4—H41	110 (12)

D—H···A	D—H	H···A	D···A	D—H···A
O4—H42···O22ii	0.81 (11)	2.23 (9)	2.933 (9)	146 (14)
O4—H41···O22	0.83 (8)	1.98 (8)	2.803 (10)	175 (13)
O3—H31···N11	0.82 (9)	1.94 (9)	2.754 (9)	170 (13)
O3—H32···O4iii	0.82 (6)	1.90 (9)	2.707 (12)	170 (13)

Table 1

Hydrogen-bond geometry (Å, °)

D—H⋯A	D—H	H⋯A	D⋯A	D—H⋯A
O4—H42⋯O22i	0.81 (11)	2.23 (9)	2.933 (9)	146 (14)
O4—H41⋯O22	0.83 (8)	1.98 (8)	2.803 (10)	175 (13)
O3—H31⋯N11	0.82 (9)	1.94 (9)	2.754 (9)	170 (13)
O3—H32⋯O4ii	0.82 (6)	1.90 (9)	2.707 (12)	170 (13)

Symmetry codes: (i) ; (ii) .