Hydro­thermal synthesis, crystal structure and properties of a two-dimensional uranyl coordination polymer based on a flexible zwitterionic ligand

The inter­action between the uranyl cation, (UO₂)²⁺, and organic species is of inter­est due to the potential applications of the resulting compounds with regard to nuclear waste disposal and nuclear fuel reprocessing. The hydro­thermal reaction of various uranyl compounds with flexible zwitterionic 1,1′-[1,4-phenyl­enebis(methyl­ene)]bis­(pyridin-1-ium-4-carboxyl­ate) di­hydro­chlo­ride (Bpmb·2HCl) in deionized water containing drops of H₂SO₄ resulted in the formation of a novel two-dimensional uranyl coordination polymer, namely poly[tetra­oxido{μ₂-1,1′-[1,4-phenyl­enebis(methyl­ene)]bis­(pyridin-1-ium-4-car­boxyl­ate)}di-μ₃-sulfato-diuranium(VI)], [(UO₂)₂(SO₄)₂(C₂₀H₁₆N₂O₄)]_n, (1). Single-crystal X-ray diffraction reveals that this coordination polymer exhibits a layered arrangement and the (UO₂)²⁺ centre is coordinated by five equatorial O atoms. The structure was further characterized by FT–IR spectroscopy, powder X-ray diffraction (PXRD) and thermogravimetric analysis (TGA). The polymer shows high thermal stability up to 696 K. Furthermore, the photo­luminescence properties of (1) has also been studied, showing it to exhibit a typical uranyl fluorescence.

Computing details

Data collection: CrysAlis PRO (Agilent, 2014); cell refinement: CrysAlis PRO (Agilent, 2014); data reduction: CrysAlis PRO (Agilent, 2014); program(s) used to solve structure: SHELXT (Sheldrick, 2015a); program(s) used to refine structure: SHELXL2014 (Sheldrick, 2015b); molecular graphics: OLEX2 (Dolomanov et al., 2009); software used to prepare material for publication: OLEX2 (Dolomanov et al., 2009).

Poly[tetraoxido{µ₂-1,1'-[1,4-phenylenebis(methylene)]bis(pyridin-1-ium-4-carboxylate)}di-µ₃-sulfato-diuranium(VI)]

Crystal data

[U2O4(SO4)2(C20H16N2O4)]	Z = 1
Mr = 1080.52	F(000) = 494
Triclinic, P1	Dx = 2.511 Mg m^−3
a = 6.9406 (2) Å	Cu Kα radiation, λ = 1.54184 Å
b = 8.5527 (3) Å	Cell parameters from 4875 reflections
c = 12.7193 (6) Å	θ = 3.7–71.8°
α = 108.581 (4)°	µ = 33.72 mm^−1
β = 90.930 (3)°	T = 288 K
γ = 92.396 (3)°	, clear orangish orange
V = 714.70 (5) Å^3	0.1 × 0.06 × 0.06 mm

Data collection

Agilent Gemini Dual Source diffractometer with an Eos detector	2521 independent reflections
Radiation source: Enhance (Cu) X-ray Source	2372 reflections with I > 2σ(I)
Graphite monochromator	Rint = 0.064
Detector resolution: 15.9595 pixels mm^-1	θmax = 66.6°, θmin = 3.7°
ω scans	h = −7→8
Absorption correction: multi-scan (CrysAlis PRO; Agilent, 2014)	k = −8→10
Tmin = 0.121, Tmax = 1.000	l = −15→15
7889 measured reflections

Refinement

Refinement on F^2	0 restraints
Least-squares matrix: full	Hydrogen site location: inferred from neighbouring sites
R[F^2 > 2σ(F^2)] = 0.046	H-atom parameters constrained
wR(F^2) = 0.111	w = 1/[σ^2(Fo^2) + (0.078P)^2] where P = (Fo^2 + 2Fc^2)/3
S = 1.06	(Δ/σ)max < 0.001
2521 reflections	Δρmax = 2.91 e Å^−3
190 parameters	Δρmin = −2.23 e Å^−3

Special details

Geometry. All esds (except the esd in the dihedral angle between two l.s. planes) are estimated using the full covariance matrix. The cell esds are taken into account individually in the estimation of esds in distances, angles and torsion angles; correlations between esds in cell parameters are only used when they are defined by crystal symmetry. An approximate (isotropic) treatment of cell esds is used for estimating esds involving l.s. planes.

Fractional atomic coordinates and isotropic or equivalent isotropic displacement parameters (Ų)

	x	y	z	Uiso*/Ueq
S2	0.2516 (3)	0.5572 (3)	0.12876 (18)	0.0232 (5)
O3	0.0929 (10)	0.6697 (9)	0.1300 (6)	0.0284 (15)
O4	0.9521 (12)	0.7640 (11)	0.3536 (6)	0.0399 (19)
O5	0.2274 (13)	0.4741 (10)	0.2105 (7)	0.0388 (19)
N6	0.8345 (13)	0.8894 (10)	0.7584 (7)	0.0242 (17)
O7	0.4355 (11)	0.6602 (11)	0.1476 (7)	0.0366 (18)
O8	0.7726 (13)	0.8820 (10)	0.1700 (7)	0.0353 (18)
O9	0.6372 (12)	0.7869 (11)	0.3654 (7)	0.0415 (19)
OA	0.7646 (12)	0.4695 (10)	0.1901 (8)	0.0363 (18)
CB	0.8198 (18)	0.8320 (14)	0.5337 (9)	0.033 (2)
CC	0.6669 (15)	0.9619 (13)	0.9388 (9)	0.027 (2)
OD	0.2548 (13)	0.4338 (11)	0.0162 (7)	0.0392 (19)
CE	0.5118 (17)	0.8475 (13)	0.9193 (9)	0.030 (2)
HE	0.5199	0.7448	0.8656	0.036*
CF	0.8052 (19)	0.7951 (14)	0.4123 (10)	0.036 (3)
CG	0.3449 (16)	0.8844 (11)	0.9790 (8)	0.027 (2)
HG	0.2412	0.8073	0.9645	0.032*
CH	0.8535 (15)	0.9215 (13)	0.8808 (8)	0.027 (2)
HA	0.9023	0.8248	0.8942	0.033*
HB	0.9472	1.0127	0.9121	0.033*
CI	0.7004 (19)	0.9601 (16)	0.7153 (10)	0.039 (3)
HI	0.6155	1.0299	0.7614	0.046*
CJ	0.9679 (19)	0.7971 (16)	0.6944 (10)	0.038 (3)
HJ	1.0619	0.7515	0.7270	0.046*
CK	0.688 (2)	0.9292 (17)	0.6010 (10)	0.044 (3)
HK	0.5903	0.9740	0.5702	0.052*
CL	0.9673 (19)	0.7693 (15)	0.5821 (10)	0.039 (3)
HL	1.0632	0.7098	0.5390	0.047*
U1	0.76728 (4)	0.67383 (3)	0.17665 (2)	0.02069 (16)

Atomic displacement parameters (Ų)

	U^11	U^22	U^33	U^12	U^13	U^23
S2	0.0141 (11)	0.0340 (11)	0.0202 (10)	0.0047 (9)	0.0012 (8)	0.0064 (9)
O3	0.009 (3)	0.042 (4)	0.036 (4)	0.007 (3)	0.005 (3)	0.015 (3)
O4	0.027 (4)	0.064 (5)	0.027 (4)	0.009 (4)	0.003 (3)	0.011 (4)
O5	0.045 (5)	0.044 (4)	0.034 (4)	0.013 (4)	0.007 (4)	0.020 (4)
N6	0.023 (4)	0.028 (4)	0.023 (4)	0.001 (3)	−0.002 (3)	0.010 (3)
O7	0.007 (3)	0.053 (5)	0.050 (5)	0.003 (3)	−0.002 (3)	0.017 (4)
O8	0.031 (5)	0.038 (4)	0.040 (4)	0.007 (3)	0.000 (4)	0.017 (4)
O9	0.025 (4)	0.063 (5)	0.035 (4)	0.007 (4)	−0.002 (3)	0.012 (4)
OA	0.023 (4)	0.041 (4)	0.049 (5)	−0.001 (3)	−0.004 (4)	0.020 (4)
CB	0.034 (6)	0.034 (5)	0.031 (6)	0.008 (5)	0.003 (5)	0.010 (4)
CC	0.017 (5)	0.037 (5)	0.031 (5)	0.002 (4)	0.003 (4)	0.017 (4)
OD	0.032 (5)	0.052 (5)	0.027 (4)	0.010 (4)	0.000 (3)	0.003 (4)
CE	0.028 (6)	0.028 (5)	0.032 (5)	0.003 (4)	0.004 (5)	0.006 (4)
CF	0.038 (7)	0.032 (5)	0.031 (6)	0.010 (5)	0.006 (5)	0.001 (4)
CG	0.027 (6)	0.022 (4)	0.030 (5)	0.004 (4)	−0.005 (4)	0.007 (4)
CH	0.020 (5)	0.040 (5)	0.022 (5)	0.004 (4)	0.001 (4)	0.008 (4)
CI	0.038 (7)	0.050 (6)	0.031 (6)	0.013 (5)	0.004 (5)	0.015 (5)
CJ	0.034 (7)	0.050 (6)	0.033 (6)	0.016 (5)	0.007 (5)	0.016 (5)
CK	0.046 (8)	0.056 (7)	0.030 (6)	0.020 (6)	0.004 (5)	0.014 (5)
CL	0.035 (7)	0.051 (6)	0.030 (6)	0.015 (5)	0.006 (5)	0.008 (5)
U1	0.0137 (2)	0.0255 (2)	0.0218 (2)	0.00204 (13)	0.00166 (13)	0.00585 (14)

Geometric parameters (Å, º)

S2—O3	1.490 (7)	CC—CE	1.388 (15)
S2—O5	1.442 (8)	CC—CG^ii	1.402 (15)
S2—O7	1.492 (8)	CC—CH	1.499 (15)
S2—OD	1.484 (8)	OD—U1^iii	2.330 (8)
O3—U1^i	2.344 (7)	CE—HE	0.9300
O4—CF	1.260 (15)	CE—CG	1.387 (16)
O4—U1	2.454 (8)	CG—CC^ii	1.402 (15)
N6—CH	1.494 (12)	CG—HG	0.9300
N6—CI	1.332 (15)	CH—HA	0.9700
N6—CJ	1.349 (16)	CH—HB	0.9700
O7—U1	2.318 (7)	CI—HI	0.9300
O8—U1	1.808 (8)	CI—CK	1.393 (16)
O9—CF	1.290 (16)	CJ—HJ	0.9300
O9—U1	2.485 (9)	CJ—CL	1.371 (17)
OA—U1	1.809 (8)	CK—HK	0.9300
CB—CF	1.475 (16)	CL—HL	0.9300
CB—CK	1.379 (18)	U1—O3^iv	2.344 (7)
CB—CL	1.397 (16)	U1—OD^iii	2.330 (8)
O5—S2—O3	112.0 (5)	HA—CH—HB	107.8
O5—S2—O7	112.0 (5)	N6—CI—HI	120.1
O5—S2—OD	109.9 (5)	N6—CI—CK	119.8 (12)
O7—S2—O3	106.7 (4)	CK—CI—HI	120.1
OD—S2—O3	108.3 (5)	N6—CJ—HJ	119.4
OD—S2—O7	107.8 (5)	N6—CJ—CL	121.1 (11)
S2—O3—U1^i	134.7 (4)	CL—CJ—HJ	119.4
CF—O4—U1	94.5 (7)	CB—CK—CI	119.8 (12)
CI—N6—CH	121.1 (9)	CB—CK—HK	120.1
CI—N6—CJ	121.2 (10)	CI—CK—HK	120.1
CJ—N6—CH	117.4 (9)	CB—CL—HL	120.6
S2—O7—U1	147.3 (5)	CJ—CL—CB	118.7 (11)
CF—O9—U1	92.3 (7)	CJ—CL—HL	120.6
CK—CB—CF	120.3 (11)	O3^iv—U1—O4	74.2 (3)
CK—CB—CL	119.0 (11)	O3^iv—U1—O9	126.6 (3)
CL—CB—CF	120.6 (11)	O4—U1—O9	53.0 (3)
CE—CC—CG^ii	119.3 (10)	O7—U1—O3^iv	157.1 (3)
CE—CC—CH	122.0 (10)	O7—U1—O4	128.3 (3)
CG^ii—CC—CH	118.5 (9)	O7—U1—O9	75.4 (3)
S2—OD—U1^iii	158.9 (6)	O7—U1—OD^iii	79.5 (3)
CC—CE—HE	119.6	O8—U1—O3^iv	86.7 (3)
CC—CE—CG	120.9 (10)	O8—U1—O4	91.6 (3)
CG—CE—HE	119.6	O8—U1—O7	88.4 (3)
O4—CF—O9	119.8 (11)	O8—U1—O9	87.3 (4)
O4—CF—CB	121.2 (11)	O8—U1—OD^iii	90.7 (4)
O9—CF—CB	118.9 (11)	OA—U1—O3^iv	93.4 (3)
CC^ii—CG—HG	120.1	OA—U1—O4	85.9 (3)
CE—CG—CC^ii	119.8 (10)	OA—U1—O7	92.5 (3)
CE—CG—HG	120.1	OA—U1—O8	177.4 (3)
N6—CH—HA	108.9	OA—U1—O9	90.5 (4)
N6—CH—HB	108.9	OA—U1—OD^iii	91.9 (4)
CC—CH—N6	113.2 (8)	OD^iii—U1—O3^iv	78.2 (3)
CC—CH—HA	108.9	OD^iii—U1—O4	152.1 (3)
CC—CH—HB	108.9	OD^iii—U1—O9	154.8 (3)

Symmetry codes: (i) x−1, y, z; (ii) −x+1, −y+2, −z+2; (iii) −x+1, −y+1, −z; (iv) x+1, y, z.