Poly[diaqua-μ4-oxalato-di-μ6-phosphato-tetra­cobalt(II)]

Wu, W.-Y.; Zhai, L.-X.

doi:10.1107/S1600536808002912

metal-organic compounds

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ISSN: 2056-9890

Volume 64| Part 2| February 2008| Page m436

doi:10.1107/S1600536808002912

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Poly[diaqua-μ₄-oxalato-di-μ₆-phosphato-tetracobalt(II)]

Wen-Yuan Wu ^a ^* and Li-Xin Zhai ^b

^aDepartment of Applied Chemistry, College of Science, Nanjing University of Technology, Nanjing 210009, People's Republic of China, and ^bCenter of Chemical Laboratory, College of Science, Nanjing University of Technology, Nanjing 210009, People's Republic of China
^*Correspondence e-mail: wwy@njut.edu.cn

(Received 15 November 2007; accepted 25 January 2008; online 30 January 2008)

In the structure of the title compound, [Co₄(C₂O₄)(PO₄)₂(H₂O)₂]_n, there are layers composed of the phosphate anions and two independent Co^II cations. These layers are parallel to (001) and are bridged by the oxalate anions that are situated in special positions on centres of symmetry. One independent Co atom has an octahedral coordination, while the second independent Co atom is coordinated in a trigonal–bipyramidal coordination that includes the water molecule. The crystal packing is stabilized by O—H⋯O hydrogen bonds between the coordinated water molecules and oxalate O atoms.

Related literature

For general background, see Lethbridge et al. (2004 ). For the related structure (C₄N₂H₁₂)_0.5[Co₂(HPO₄)(C₂O₄)_1.5], which also contains the unusual CoO₅ trigonal–bipyramidal configuration, see Choudhury & Natarajan (2000 ). For the O—H⋯O hydrogen bonding, see Desiraju & Steiner (1999 ).

Experimental

Crystal data

[Co₄(C₂O₄)(PO₄)₂(H₂O)₂]
M_r = 549.72
Monoclinic, P 2₁ /n
a = 7.8541 (17) Å
b = 4.7829 (10) Å
c = 14.057 (3) Å
β = 95.937 (4)°
V = 525.2 (2) Å³
Z = 2
Mo Kα radiation
μ = 6.60 mm⁻¹
T = 293 (2) K
0.32 × 0.20 × 0.10 mm

Data collection

Bruker SMART APEX CCD area-detector diffractometer
Absorption correction: multi-scan (SADABS; Bruker, 2000 ) T_min = 0.22, T_max = 0.52
2798 measured reflections
1133 independent reflections
913 reflections with I > 2σ(I)
R_int = 0.034

Refinement

R[F² > 2σ(F²)] = 0.040
wR(F²) = 0.094
S = 1.09
1133 reflections
107 parameters
3 restraints
All H-atom parameters refined
Δρ_max = 0.90 e Å⁻³
Δρ_min = −0.81 e Å⁻³

Table 1
Hydrogen-bond geometry (Å, °)

D—H⋯A	D—H	H⋯A	D⋯A	D—H⋯A
O7—H2⋯O6ⁱ	0.84 (2)	1.94 (3)	2.665 (5)	144 (5)
O7—H1⋯O6ⁱⁱ	0.84 (2)	2.46 (4)	3.188 (5)	145 (5)
Symmetry codes: (i) $[-x+{\script{3\over 2}}, y-{\script{1\over 2}}, -z+{\script{3\over 2}}]$ ; (ii) $[-x+{\script{3\over 2}}, y+{\script{1\over 2}}, -z+{\script{3\over 2}}]$ .

Data collection: SMART (Bruker, 2000); cell refinement: SMART; data reduction: SAINT-Plus (Bruker, 2000); program(s) used to solve structure: SHELXTL (Sheldrick, 2008 ); program(s) used to refine structure: SHELXTL; molecular graphics: SHELXTL; software used to prepare material for publication: SHELXTL.

Supporting information

Crystal structure: contains datablocks global, I. DOI: 10.1107/S1600536808002912/fb2073sup1.cif

Structure factors: contains datablock I. DOI: 10.1107/S1600536808002912/fb2073Isup2.hkl

checkCIF report

Comment top

A new class of metal phosphate-oxalates framework structures has been discovered in recent years. In this new class the anions [PO₄]^3- (or [HPO₄]^2-) and [C₂O₄]^2- act as bridging groups that link up with the metal atoms. Both main-group metals (Al, Ga, In, Sn) and transition metals (V, Mn, Fe, Co, Mo) are reported in these systems (Lethbridge et al., 2004). Among these, to the best of our knowledge there is only one example containing Co^II: [C₄N₂H₁₂]_0.5[Co₂(HPO₄)(C₂O₄)_1.5] (Choudhury & Natarajan, 2000). Here we report the synthesis and the crystal structure of a new oxalate phosphate framework structure containing Co^II, [Co₄(C₂O₄)(PO₄)₂(H₂O)₂].

The asymmetric unit of the title structure contains two independent Co cations (Fig. 1). Co1 is octahedrally coordinated by six oxygen atoms and Co2 is coordinated by 5 O atoms in a trigonal-bipyramidal configuration. Each phosphate acts as a multiple bridging group, binding six Co atoms to compose the inorganic layer structure. The oxalate group is situated on an inversion centre and links up with two adjacent inorganic layers. The water molecule is coordinated to Co2 (Fig. 2).

Related literature top

For general background, see Lethbridge et al. (2004). For the related structure (C₄N₂H₁₂)_0.5[Co₂(HPO₄)(C₂O₄)_1.5], which also contains the unusual CoO₅ trigonal–bipyramidal configuration, see Choudhury & Natarajan (2000). For the O—H···O hydrogen bonding, see Desiraju & Steiner (1999).

Experimental top

A mixture of Co(ClO₄)₂.6H₂O (0.1830 g, 0.5 mmol), H₂C₂O₄.2H₂O (0.2521 g, 2 mmol), Na₄P₂O₇.10H₂O (0.8921 g, 2 mmol) and distilled water (10 ml) was placed into a 23 ml teflon-lined autoclave. The mixture was then heated for 72 h at 425 K. The insoluble purple crystals of the title structure were separated by filtration. The crystals were of rectangular plate-like shape with the average size of 0.4 × 0.3 × 0.1 mm.

Computing details top

Data collection: SMART (Bruker, 2000); cell refinement: SMART (Bruker, 2000); data reduction: SAINT-Plus (Bruker, 2000); program(s) used to solve structure: SHELXTL (Sheldrick, 2008); program(s) used to refine structure: SHELXTL (Sheldrick, 2008); molecular graphics: SHELXTL (Sheldrick, 2008); software used to prepare material for publication: SHELXTL (Sheldrick, 2008).

Figures top

	Fig. 1. Coordination environment of Co and P atoms in the title structure. The displacement ellipsoids are shown at the 50% probability level. [Symmetry codes: (i) 1 - x, 1 - y, 2 - z; (ii) x, 1 + y, z; (iii) 1/2 - x, 1/2 + y, 3/2 - z; (iv) 3/2 - x, 1/2 + y, 3/2 - z; (v) 3/2 - x, -1/2 + y, 3/2 - z.]
	Fig. 2. The packing of the title structure viewed down the b axis, showing the cobalt phosphate layers bridged by the oxalate ligands. The hydrogen bonds are shown as dashed lines.

Poly[diaqua-µ₄-oxalato-di-µ₆-phosphato-tetracobalt(II)] top

Crystal data top

[Co₄(C₂O₄)(PO₄)₂(H₂O)₂]	F(000) = 532
M_r = 549.72	D_x = 3.476 Mg m⁻³
Monoclinic, P2₁/n	Mo Kα radiation, λ = 0.71073 Å
Hall symbol: -P 2yn	Cell parameters from 897 reflections
a = 7.8541 (17) Å	θ = 2.9–27.0°
b = 4.7829 (10) Å	µ = 6.60 mm⁻¹
c = 14.057 (3) Å	T = 293 K
β = 95.937 (4)°	Plate, purple
V = 525.2 (2) Å³	0.32 × 0.20 × 0.10 mm
Z = 2

Data collection top

Bruker SMART APEX CCD area-detector diffractometer	1133 independent reflections
Radiation source: fine-focus sealed tube	913 reflections with I > 2σ(I)
Graphite monochromator	R_int = 0.034
ϕ and ω scans	θ_max = 27.0°, θ_min = 2.9°
Absorption correction: multi-scan (SADABS; Bruker, 2000)	h = −9→10
T_min = 0.22, T_max = 0.52	k = −6→6
2798 measured reflections	l = −10→17

Refinement top

Refinement on F²	Secondary atom site location: difference Fourier map
Least-squares matrix: full	Hydrogen site location: difference Fourier map
R[F² > 2σ(F²)] = 0.040	All H-atom parameters refined
wR(F²) = 0.094	w = 1/[σ²(F_o²) + (0.0537P)²] where P = (F_o² + 2F_c²)/3
S = 1.09	(Δ/σ)_max < 0.001
1133 reflections	Δρ_max = 0.90 e Å⁻³
107 parameters	Δρ_min = −0.81 e Å⁻³
3 restraints	Extinction correction: SHELXTL (Sheldrick, 2008), Fc^*=kFc[1+0.001xFc²λ³/sin(2θ)]^-1/4
Primary atom site location: structure-invariant direct methods	Extinction coefficient: 0.0094 (17)

Crystal data top

[Co₄(C₂O₄)(PO₄)₂(H₂O)₂]	V = 525.2 (2) Å³
M_r = 549.72	Z = 2
Monoclinic, P2₁/n	Mo Kα radiation
a = 7.8541 (17) Å	µ = 6.60 mm⁻¹
b = 4.7829 (10) Å	T = 293 K
c = 14.057 (3) Å	0.32 × 0.20 × 0.10 mm
β = 95.937 (4)°

Data collection top

Bruker SMART APEX CCD area-detector diffractometer	1133 independent reflections
Absorption correction: multi-scan (SADABS; Bruker, 2000)	913 reflections with I > 2σ(I)
T_min = 0.22, T_max = 0.52	R_int = 0.034
2798 measured reflections

Refinement top

R[F² > 2σ(F²)] = 0.040	3 restraints
wR(F²) = 0.094	All H-atom parameters refined
S = 1.09	Δρ_max = 0.90 e Å⁻³
1133 reflections	Δρ_min = −0.81 e Å⁻³
107 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

	x	y	z	U_iso*/U_eq
Co1	0.40849 (8)	0.46997 (13)	0.80563 (5)	0.0130 (2)
Co2	0.70451 (8)	0.47453 (13)	0.63392 (5)	0.0122 (2)
P1	0.50343 (17)	0.0223 (3)	0.69630 (10)	0.0139 (3)
O1	0.5074 (4)	−0.2997 (7)	0.6975 (2)	0.0126 (7)
O2	0.5646 (4)	0.1346 (7)	0.6038 (2)	0.0155 (7)
O3	0.6187 (4)	0.1571 (8)	0.7802 (2)	0.0158 (7)
O4	0.3244 (4)	0.1379 (7)	0.7118 (2)	0.0148 (7)
C1	0.5588 (6)	0.6255 (11)	0.9925 (4)	0.0171 (10)
O5	0.5694 (4)	0.7013 (8)	0.9079 (2)	0.0183 (8)
O6	0.6373 (4)	0.7274 (7)	1.0660 (2)	0.0134 (7)
O7	0.7066 (4)	0.6605 (9)	0.5068 (2)	0.0197 (8)
H2	0.782 (4)	0.584 (4)	0.478 (3)	0.030*
H1	0.733 (4)	0.830 (4)	0.512 (3)	0.030*

Atomic displacement parameters (Å²) top

	U¹¹	U²²	U³³	U¹²	U¹³	U²³
Co1	0.0123 (4)	0.0124 (4)	0.0136 (4)	−0.0042 (2)	−0.0026 (3)	−0.0010 (2)
Co2	0.0129 (4)	0.0118 (4)	0.0109 (4)	−0.0044 (2)	−0.0034 (3)	−0.0011 (2)
P1	0.0132 (6)	0.0138 (6)	0.0146 (7)	0.0006 (4)	0.0005 (5)	−0.0003 (4)
O1	0.0105 (15)	0.0154 (17)	0.0116 (17)	−0.0009 (13)	−0.0003 (13)	0.0001 (13)
O2	0.0181 (17)	0.0162 (18)	0.0126 (18)	0.0010 (13)	0.0039 (13)	−0.0023 (13)
O3	0.0123 (16)	0.0203 (18)	0.0143 (18)	−0.0014 (13)	−0.0008 (14)	−0.0047 (14)
O4	0.0136 (16)	0.0171 (17)	0.0136 (16)	0.0010 (13)	0.0001 (12)	−0.0011 (14)
C1	0.019 (2)	0.022 (3)	0.012 (2)	−0.003 (2)	0.0089 (19)	0.0024 (19)
O5	0.0235 (19)	0.0231 (19)	0.0074 (17)	−0.0043 (14)	−0.0018 (14)	−0.0004 (14)
O6	0.0164 (17)	0.0176 (17)	0.0054 (16)	−0.0056 (13)	−0.0033 (12)	0.0010 (12)
O7	0.0190 (19)	0.028 (2)	0.0119 (19)	0.0034 (15)	0.0019 (14)	0.0053 (15)

Geometric parameters (Å, º) top

Co1—O4ⁱ	1.989 (3)	P1—O4	1.547 (3)
Co1—O1ⁱⁱ	2.090 (3)	P1—O3	1.551 (3)
Co1—O6ⁱⁱⁱ	2.101 (3)	O1—Co1^vi	2.090 (3)
Co1—O5	2.124 (4)	O1—Co2^vi	2.156 (3)
Co1—O4	2.126 (4)	O3—Co2^v	1.950 (3)
Co1—O3	2.284 (3)	O4—Co1^vii	1.989 (3)
Co2—O3^iv	1.950 (3)	C1—O6	1.246 (6)
Co2—O2	1.983 (4)	C1—O5	1.254 (6)
Co2—O7	1.997 (4)	C1—C1ⁱⁱⁱ	1.542 (10)
Co2—O1ⁱⁱ	2.156 (3)	O5—Co2^iv	2.329 (4)
Co2—O5^v	2.329 (4)	O6—Co1ⁱⁱⁱ	2.101 (3)
P1—O2	1.530 (4)	O7—H2	0.84 (2)
P1—O1	1.541 (4)	O7—H1	0.84 (2)

O4ⁱ—Co1—O1ⁱⁱ	95.97 (14)	O2—P1—O4	111.3 (2)
O4ⁱ—Co1—O6ⁱⁱⁱ	92.87 (14)	O1—P1—O4	111.9 (2)
O1ⁱⁱ—Co1—O6ⁱⁱⁱ	166.14 (13)	O2—P1—O3	106.9 (2)
O4ⁱ—Co1—O5	110.36 (15)	O1—P1—O3	113.4 (2)
O1ⁱⁱ—Co1—O5	88.72 (13)	O4—P1—O3	102.26 (19)
O6ⁱⁱⁱ—Co1—O5	78.19 (13)	P1—O1—Co1^vi	121.8 (2)
O4ⁱ—Co1—O4	90.16 (9)	P1—O1—Co2^vi	120.69 (19)
O1ⁱⁱ—Co1—O4	93.29 (13)	Co1^vi—O1—Co2^vi	111.99 (15)
O6ⁱⁱⁱ—Co1—O4	97.35 (14)	P1—O2—Co2	108.8 (2)
O5—Co1—O4	159.08 (14)	P1—O3—Co2^v	127.4 (2)
O4ⁱ—Co1—O3	156.31 (14)	P1—O3—Co1	90.96 (15)
O1ⁱⁱ—Co1—O3	84.41 (13)	Co2^v—O3—Co1	132.59 (17)
O6ⁱⁱⁱ—Co1—O3	91.76 (13)	P1—O4—Co1^vii	132.5 (2)
O5—Co1—O3	93.33 (13)	P1—O4—Co1	97.21 (17)
O4—Co1—O3	66.20 (12)	Co1^vii—O4—Co1	126.90 (16)
O3^iv—Co2—O2	147.43 (15)	O6—C1—O5	126.7 (4)
O3^iv—Co2—O7	106.46 (15)	O6—C1—C1ⁱⁱⁱ	116.3 (5)
O2—Co2—O7	103.26 (16)	O5—C1—C1ⁱⁱⁱ	117.0 (6)
O3^iv—Co2—O1ⁱⁱ	90.85 (14)	C1—O5—Co1	113.4 (3)
O2—Co2—O1ⁱⁱ	95.36 (13)	C1—O5—Co2^iv	121.9 (3)
O7—Co2—O1ⁱⁱ	102.74 (14)	Co1—O5—Co2^iv	122.52 (15)
O3^iv—Co2—O5^v	83.95 (13)	C1—O6—Co1ⁱⁱⁱ	115.0 (3)
O2—Co2—O5^v	84.61 (13)	Co2—O7—H2	108 (2)
O7—Co2—O5^v	86.98 (14)	Co2—O7—H1	113 (5)
O1ⁱⁱ—Co2—O5^v	169.97 (13)	H2—O7—H1	107 (3)
O2—P1—O1	110.7 (2)

O2—P1—O1—Co1^vi	−173.41 (19)	O3—P1—O4—Co1^vii	−142.9 (3)
O4—P1—O1—Co1^vi	−48.6 (3)	O2—P1—O4—Co1	−97.2 (2)
O3—P1—O1—Co1^vi	66.5 (3)	O1—P1—O4—Co1	138.41 (17)
O2—P1—O1—Co2^vi	35.0 (3)	O3—P1—O4—Co1	16.7 (2)
O4—P1—O1—Co2^vi	159.81 (19)	O4ⁱ—Co1—O4—P1	166.4 (2)
O3—P1—O1—Co2^vi	−85.1 (3)	O1ⁱⁱ—Co1—O4—P1	70.39 (18)
O1—P1—O2—Co2	−141.52 (19)	O6ⁱⁱⁱ—Co1—O4—P1	−100.71 (18)
O4—P1—O2—Co2	93.3 (2)	O5—Co1—O4—P1	−24.6 (5)
O3—P1—O2—Co2	−17.6 (2)	O3—Co1—O4—P1	−12.03 (15)
O3^iv—Co2—O2—P1	42.8 (4)	O4ⁱ—Co1—O4—Co1^vii	−32.3 (2)
O7—Co2—O2—P1	−161.77 (19)	O1ⁱⁱ—Co1—O4—Co1^vii	−128.3 (2)
O1ⁱⁱ—Co2—O2—P1	−57.3 (2)	O6ⁱⁱⁱ—Co1—O4—Co1^vii	60.6 (2)
O5^v—Co2—O2—P1	112.6 (2)	O5—Co1—O4—Co1^vii	136.7 (3)
O2—P1—O3—Co2^v	−108.5 (3)	O3—Co1—O4—Co1^vii	149.3 (3)
O1—P1—O3—Co2^v	13.8 (3)	O6—C1—O5—Co1	−179.2 (4)
O4—P1—O3—Co2^v	134.4 (2)	C1ⁱⁱⁱ—C1—O5—Co1	2.9 (7)
O2—P1—O3—Co1	101.70 (17)	O6—C1—O5—Co2^iv	17.1 (7)
O1—P1—O3—Co1	−136.07 (17)	C1ⁱⁱⁱ—C1—O5—Co2^iv	−160.8 (4)
O4—P1—O3—Co1	−15.39 (19)	O4ⁱ—Co1—O5—C1	86.3 (4)
O4ⁱ—Co1—O3—P1	7.9 (4)	O1ⁱⁱ—Co1—O5—C1	−177.8 (4)
O1ⁱⁱ—Co1—O3—P1	−84.19 (17)	O6ⁱⁱⁱ—Co1—O5—C1	−2.4 (3)
O6ⁱⁱⁱ—Co1—O3—P1	109.16 (17)	O4—Co1—O5—C1	−82.0 (5)
O5—Co1—O3—P1	−172.57 (17)	O3—Co1—O5—C1	−93.5 (4)
O4—Co1—O3—P1	11.90 (15)	O4ⁱ—Co1—O5—Co2^iv	−110.0 (2)
O4ⁱ—Co1—O3—Co2^v	−139.2 (3)	O1ⁱⁱ—Co1—O5—Co2^iv	−14.1 (2)
O1ⁱⁱ—Co1—O3—Co2^v	128.6 (2)	O6ⁱⁱⁱ—Co1—O5—Co2^iv	161.3 (2)
O6ⁱⁱⁱ—Co1—O3—Co2^v	−38.0 (2)	O4—Co1—O5—Co2^iv	81.7 (4)
O5—Co1—O3—Co2^v	40.3 (2)	O3—Co1—O5—Co2^iv	70.2 (2)
O4—Co1—O3—Co2^v	−135.3 (3)	O5—C1—O6—Co1ⁱⁱⁱ	−177.6 (4)
O2—P1—O4—Co1^vii	103.2 (3)	C1ⁱⁱⁱ—C1—O6—Co1ⁱⁱⁱ	0.3 (7)
O1—P1—O4—Co1^vii	−21.2 (4)

Symmetry codes: (i) −x+1/2, y+1/2, −z+3/2; (ii) x, y+1, z; (iii) −x+1, −y+1, −z+2; (iv) −x+3/2, y+1/2, −z+3/2; (v) −x+3/2, y−1/2, −z+3/2; (vi) x, y−1, z; (vii) −x+1/2, y−1/2, −z+3/2.

Hydrogen-bond geometry (Å, º) top

D—H···A	D—H	H···A	D···A	D—H···A
O7—H2···O6^v	0.84 (2)	1.94 (3)	2.665 (5)	144 (5)
O7—H1···O6^iv	0.84 (2)	2.46 (4)	3.188 (5)	145 (5)

Symmetry codes: (iv) −x+3/2, y+1/2, −z+3/2; (v) −x+3/2, y−1/2, −z+3/2.

Experimental details

Crystal data
Chemical formula	[Co₄(C₂O₄)(PO₄)₂(H₂O)₂]
M_r	549.72
Crystal system, space group	Monoclinic, P2₁/n
Temperature (K)	293
a, b, c (Å)	7.8541 (17), 4.7829 (10), 14.057 (3)
β (°)	95.937 (4)
V (Å³)	525.2 (2)
Z	2
Radiation type	Mo Kα
µ (mm⁻¹)	6.60
Crystal size (mm)	0.32 × 0.20 × 0.10

Data collection
Diffractometer	Bruker SMART APEX CCD area-detector diffractometer
Absorption correction	Multi-scan (SADABS; Bruker, 2000)
T_min, T_max	0.22, 0.52
No. of measured, independent and observed [I > 2σ(I)] reflections	2798, 1133, 913
R_int	0.034
(sin θ/λ)_max (Å⁻¹)	0.639

Refinement
R[F² > 2σ(F²)], wR(F²), S	0.040, 0.094, 1.09
No. of reflections	1133
No. of parameters	107
No. of restraints	3
H-atom treatment	All H-atom parameters refined
Δρ_max, Δρ_min (e Å⁻³)	0.90, −0.81

Computer programs: SMART (Bruker, 2000), SAINT-Plus (Bruker, 2000), SHELXTL (Sheldrick, 2008).

Hydrogen-bond geometry (Å, º) top

D—H···A	D—H	H···A	D···A	D—H···A
O7—H2···O6ⁱ	0.84 (2)	1.94 (3)	2.665 (5)	144 (5)
O7—H1···O6ⁱⁱ	0.84 (2)	2.46 (4)	3.188 (5)	145 (5)

Symmetry codes: (i) −x+3/2, y−1/2, −z+3/2; (ii) −x+3/2, y+1/2, −z+3/2.

Acknowledgements

The authors thank the Center of Testing and Analysis, Nanjing University, for support.

References

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