Crystal structure of catena-poly[[di­aqua­bis­(4-formyl­benzoato-κO1)cobalt(II)]-μ-pyrazine-κ2N:N′]

Aşkın, G. Ş.; Çelik, F.; Dilek, N.; Necefoğlu, H.; Hökelek, T.

doi:10.1107/S205698901500403X

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ISSN: 2056-9890

Volume 71| Part 4| April 2015| Pages 339-341

doi:10.1107/S205698901500403X

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Crystal structure of catena-poly[[diaquabis(4-formylbenzoato-κO¹)cobalt(II)]-μ-pyrazine-κ²N:N′]

Gülçin Şefiye Aşkın,^a Fatih Çelik,^b Nefise Dilek,^c Hacali Necefoğlu ^b and Tuncer Hökelek ^a ^*

^aDepartment of Physics, Hacettepe University, 06800 Beytepe, Ankara, Turkey, ^bDepartment of Chemistry, Kafkas University, 36100 Kars, Turkey, and ^cAksaray University, Department of Physics, 68100, Aksaray, Turkey
^*Correspondence e-mail: merzifon@hacettepe.edu.tr

Edited by M. Weil, Vienna University of Technology, Austria (Received 18 February 2015; accepted 26 February 2015; online 4 March 2015)

In the title polymeric compound, [Co(C₈H₅O₃)₂(C₄H₄N₂)(H₂O)₂]_n, the Co^II atom is located on a twofold rotation axis and has a slightly distorted octahedral coordination sphere. In the equatorial plane, it is coordinated by two carboxylate O atoms of two symmetry-related monodentate formylbenzoate anions and by two N atoms of two bridging pyrazine ligands. The latter are bisected by the twofold rotation axis. The axial positions are occupied by two O atoms of the coordinating water molecules. In the formylbenzoate anion, the carboxylate group is twisted away from the attached benzene ring by 7.50 (8)°, while the benzene and pyrazine rings are oriented at a dihedral angle of 64.90 (4)°. The pyrazine ligands bridge the Co^II cations, forming linear chains running along the b-axis direction. Strong intramolecular O—H⋯O hydrogen bonds link the water molecules to the carboxylate O atoms. In the crystal, weak O—H_water⋯O_water hydrogen bonds link adjacent chains into layers parallel to the bc plane. The layers are linked via C—H_pyrazine⋯O_formyl hydrogen bonds, forming a three-dimensional network. There are also weak C—H⋯π interactions present.

Keywords: crystal structure; cobalt(II); transition metal complexes; benzoic acid derivatives; one-dimensional coordination polymer.

CCDC reference: 1051344

1. Chemical context

The structural functions and coordination relationships of the arylcarboxylate ion in transition metal complexes of benzoic acid derivatives change depending on the nature and position of the substituent groups on the benzene ring, the nature of the additional ligand molecule or solvent, and the medium of the synthesis (Adiwidjaja et al., 1978 ; Antsyshkina et al., 1980 ; Nadzhafov et al., 1981 ; Shnulin et al., 1981 ). Transition metal complexes with biochemically active ligands frequently show interesting physical and/or chemical properties and, as a result, they may find applications in biological systems (Antolini et al., 1982 ). Some benzoic acid derivatives, such as 4-aminobenzoic acid, have been extensively reported in coordination chemistry, as bifunctional organic ligands, due to the varieties of their coordination modes (Chen & Chen, 2002 ; Amiraslanov et al., 1979 ; Hauptmann et al., 2000 ).

In this context, we report the synthesis and crystal structure of the title compound, [Co(C₈H₅O₃)₂(C₄H₄N₂)(H₂O)₂]_n, which is isotypic with its Cu^II (Çelik et al., 2014a ) and Ni^II (Çelik et al., 2014b ) analogues.

2. Structural commentary

The asymmetric unit of the title compound contains a Co^II ion, one formylbenzoate (FB) anion, one water molecule and half of a pyrazine molecule. Atoms N1 and N2 of the pyrazine ligand and Co1 are located on a twofold rotation axis (Fig. 1). The pyrazine ligands bridge adjacent Co^II ions, forming polymeric chains running along the b-axis direction (Fig. 2). The distance between symmetry-related Co^II ions [Co1⋯Co1ⁱⁱⁱ; symmetry code: (iii) x, y + 1, z] is 7.1193 (4) Å.

Figure 1
A view of the coordination environment around the Co^II atom of the title molecule, showing the atom labelling. Displacement ellipsoids are drawn at the 50% probability level. The twofold rotation axis bisects atoms Co1, N1 and N2. Non-labelled atoms are generated by the symmetry code −x + 2, y, −z + $[{3\over 2}]$ .

Figure 2
A partial view of the crystal packing of the title compound.

The equatorial plane of the Co^IIO₄N₂ coordination sphere is composed of two carboxylate O atoms [O1 and O1ⁱ; symmetry code: (i) 2 − x, y, $[{3\over 2}]$ − z] of two symmetry-related monodentate formylbenzoate anions and two N atoms [N1 and N2ⁱⁱ; symmetry code: (ii) x, −1 + y, z] of two bridging pyrazine ligands, which are bisected by the twofold rotation axis. The axial positions are occupied by two O atoms (O4 and O4ⁱ) of the coordinating water molecules.

The near equality of the C1—O1 [1.272 (2) Å] and C1—O2 [1.245 (2) Å] bonds in the carboxylate group indicates a delocalized bonding arrangement, rather than localized single and double bonds. The Co—N bond length is 2.165 (9) Å, while the Co—O bond lengths are 2.0551 (9) Å (for benzoate oxygen) and 2.1491 (11) Å (for water oxygen), close to standard values. The Co1 atom is displaced by 0.1034 (2) Å from the mean plane of the carboxylate group (O1/C1/O2). The dihedral angle between the carboxylate group and the adjacent benzene ring A (C2–C7) is 7.50 (8)°, while the benzene and pyrazine rings are oriented at a dihedral angle of 64.90 (4)°.

3. Supramolecular features

Strong intramolecular O—H⋯O hydrogen bonds (Table 1) link the water molecules to the non-coordinating carboxylate oxygen atoms. In the crystal, weak O—H_water⋯O_water hydrogen bonds (Table 1) link adjacent chains into layers parallel to the bc plane. The layers are linked via C—H_pyrazine⋯O_formyl hydrogen bonds, forming a three-dimensional network (Fig. 3). There are also weak C—H⋯π interactions present (Table 1).

Table 1
Hydrogen-bond geometry (Å, °)

Cg1 is the centroid of ring A (C2–C7).

D—H⋯A	D—H	H⋯A	D⋯A	D—H⋯A
O4—H41⋯O2	0.89 (3)	1.72 (3)	2.5909 (16)	164 (2)
O4—H42⋯O4ⁱ	0.71 (3)	2.63 (3)	2.958 (2)	111 (2)
C10—H10⋯O3ⁱⁱ	0.93	2.46	3.320 (2)	154
C7—H7⋯Cg1ⁱⁱⁱ	0.93	2.65	3.4216 (15)	142
Symmetry codes: (i) -x+2, -y, -z+1; (ii) $[-x+{\script{3\over 2}}, -y+{\script{1\over 2}}, -z+2]$ ; (iii) $[x, -y, z-{\script{1\over 2}}]$ .

Figure 3
Part of the crystal structure. Intermolecular hydrogen bonds are shown as dashed lines. Non-bonding H atoms have been omitted for clarity.

4. Refinement

The experimental details including the crystal data, data collection and refinement are summarized in Table 2. Atoms H41 and H42 (for H₂O) were located in a difference Fourier map and were refined freely. The methine H atom was also located in a difference Fourier map and the C—H distance restrained to 0.984 (13) Å. The aromatic C-bound H atoms were positioned geometrically with C—H = 0.93 Å, and constrained to ride on their parent atoms, with U_iso(H) = 1.2U_eq(C).

Table 2
Experimental details

Crystal data
Chemical formula	[Co(C₈H₅O₃)₂(C₄H₄N₂)(H₂O)₂]
M_r	473.29
Crystal system, space group	Monoclinic, C2/c
Temperature (K)	296
a, b, c (Å)	22.1623 (6), 7.1193 (2), 12.2911 (3)
β (°)	94.432 (1)
V (Å³)	1933.49 (9)
Z	4
Radiation type	Mo Kα
μ (mm⁻¹)	0.94
Crystal size (mm)	0.47 × 0.22 × 0.11

Data collection
Diffractometer	Bruker SMART BREEZE CCD
Absorption correction	Multi-scan (SADABS; Bruker, 2012 )
T_min, T_max	0.830, 0.914
No. of measured, independent and observed [I > 2σ(I)] reflections	27023, 2427, 2336
R_int	0.024
(sin θ/λ)_max (Å⁻¹)	0.668

Refinement
R[F² > 2σ(F²)], wR(F²), S	0.025, 0.071, 1.06
No. of reflections	2427
No. of parameters	154
No. of restraints	1
H-atom treatment	H atoms treated by a mixture of independent and constrained refinement
Δρ_max, Δρ_min (e Å⁻³)	0.35, −0.34
Computer programs: APEX2 and SAINT (Bruker, 2012), SHELXS97 and SHELXL97 (Sheldrick, 2008 ), ORTEP-3 for Windows and WinGX (Farrugia, 2012 ) and PLATON (Spek, 2009 ).

5. Synthesis and crystallization

The title compound was prepared by the reaction of CoSO₄·7H₂O (1.40 g, 5 mmol) in H₂O (25 ml) and pyrazine (0.40 g, 5 mmol) in H₂O (25 ml) with sodium 4-formylbenzoate (1.72 g, 10 mmol) in H₂O (70 ml) at room temperature. The mixture was filtered and set aside to crystallize at ambient temperature for one week, giving orange single crystals.

Supporting information

CCDC reference: 1051344

Crystal structure: contains datablocks I, global. DOI: 10.1107/S205698901500403X/wm5129sup1.cif

Structure factors: contains datablock I. DOI: 10.1107/S205698901500403X/wm5129Isup2.hkl

checkCIF report

Computing details top

Data collection: APEX2 (Bruker, 2012); cell refinement: SAINT (Bruker, 2012); data reduction: SAINT (Bruker, 2012); program(s) used to solve structure: SHELXS97 (Sheldrick, 2008); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008); molecular graphics: ORTEP-3 for Windows (Farrugia, 2012); software used to prepare material for publication: WinGX (Farrugia, 2012) and PLATON (Spek, 2009).

catena-Poly[[diaquabis(4-formylbenzoato-κO¹)cobalt(II)]-µ-pyrazine-κ²N:N'] top

Crystal data top

[Co(C₈H₅O₃)₂(C₄H₄N₂)(H₂O)₂]	F(000) = 972
M_r = 473.29	D_x = 1.626 Mg m⁻³
Monoclinic, C2/c	Mo Kα radiation, λ = 0.71073 Å
Hall symbol: -C 2yc	Cell parameters from 9866 reflections
a = 22.1623 (6) Å	θ = 2.4–28.3°
b = 7.1193 (2) Å	µ = 0.94 mm⁻¹
c = 12.2911 (3) Å	T = 296 K
β = 94.432 (1)°	Block, orange
V = 1933.49 (9) Å³	0.47 × 0.22 × 0.11 mm
Z = 4

Data collection top

Bruker SMART BREEZE CCD diffractometer	2427 independent reflections
Radiation source: fine-focus sealed tube	2336 reflections with I > 2σ(I)
Graphite monochromator	R_int = 0.024
φ and ω scans	θ_max = 28.4°, θ_min = 1.8°
Absorption correction: multi-scan (SADABS; Bruker, 2012)	h = −29→29
T_min = 0.830, T_max = 0.914	k = −9→9
27023 measured reflections	l = −16→16

Refinement top

Refinement on F²	Primary atom site location: structure-invariant direct methods
Least-squares matrix: full	Secondary atom site location: difference Fourier map
R[F² > 2σ(F²)] = 0.025	Hydrogen site location: inferred from neighbouring sites
wR(F²) = 0.071	H atoms treated by a mixture of independent and constrained refinement
S = 1.06	w = 1/[σ²(F_o²) + (0.0409P)² + 1.5712P] where P = (F_o² + 2F_c²)/3
2427 reflections	(Δ/σ)_max = 0.001
154 parameters	Δρ_max = 0.35 e Å⁻³
1 restraint	Δρ_min = −0.34 e Å⁻³

Special details top

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.

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

	x	y	z	U_iso*/U_eq
Co1	1.0000	−0.05145 (3)	0.7500	0.01998 (9)
O1	0.91572 (4)	−0.04830 (13)	0.80894 (9)	0.0276 (2)
O2	0.86274 (5)	−0.17780 (18)	0.66579 (9)	0.0402 (3)
O3	0.60114 (6)	−0.1312 (3)	0.95577 (12)	0.0651 (4)
O4	0.96115 (5)	−0.06701 (18)	0.58454 (9)	0.0352 (2)
H41	0.9245 (12)	−0.104 (4)	0.600 (2)	0.058 (6)*
H42	0.9564 (12)	0.019 (4)	0.555 (2)	0.066 (8)*
N1	1.0000	0.2518 (2)	0.7500	0.0247 (3)
N2	1.0000	0.6436 (2)	0.7500	0.0235 (3)
C1	0.86731 (5)	−0.11157 (17)	0.75983 (11)	0.0240 (2)
C2	0.81095 (5)	−0.10250 (17)	0.82116 (10)	0.0226 (2)
C3	0.81105 (6)	−0.0089 (2)	0.92052 (11)	0.0268 (2)
H3	0.8467	0.0439	0.9518	0.032*
C4	0.75794 (6)	0.0058 (2)	0.97289 (11)	0.0301 (3)
H4	0.7580	0.0682	1.0394	0.036*
C5	0.70463 (6)	−0.0726 (2)	0.92617 (12)	0.0292 (3)
C6	0.70446 (6)	−0.1685 (2)	0.82755 (12)	0.0307 (3)
H6	0.6689	−0.2222	0.7967	0.037*
C7	0.75745 (6)	−0.18340 (19)	0.77557 (11)	0.0271 (3)
H7	0.7574	−0.2478	0.7098	0.032*
C8	0.64849 (8)	−0.0553 (3)	0.98296 (15)	0.0430 (4)
H8	0.6472 (7)	0.029 (2)	1.0463 (12)	0.021 (4)*
C9	0.97461 (6)	0.35053 (18)	0.82681 (11)	0.0287 (3)
H9	0.9563	0.2869	0.8815	0.034*
C10	0.97486 (7)	0.54530 (17)	0.82719 (12)	0.0282 (3)
H10	0.9571	0.6090	0.8825	0.034*

Atomic displacement parameters (Å²) top

	U¹¹	U²²	U³³	U¹²	U¹³	U²³
Co1	0.01683 (12)	0.01603 (12)	0.02763 (14)	0.000	0.00520 (8)	0.000
O1	0.0180 (4)	0.0288 (5)	0.0366 (5)	−0.0022 (3)	0.0058 (4)	−0.0040 (4)
O2	0.0284 (5)	0.0584 (7)	0.0351 (5)	−0.0116 (5)	0.0103 (4)	−0.0128 (5)
O3	0.0296 (6)	0.1092 (13)	0.0583 (8)	−0.0015 (7)	0.0149 (5)	0.0049 (9)
O4	0.0299 (5)	0.0449 (6)	0.0312 (5)	−0.0052 (5)	0.0051 (4)	0.0083 (5)
N1	0.0217 (7)	0.0178 (6)	0.0353 (8)	0.000	0.0065 (6)	0.000
N2	0.0242 (7)	0.0172 (6)	0.0301 (7)	0.000	0.0078 (6)	0.000
C1	0.0197 (5)	0.0204 (5)	0.0324 (6)	−0.0004 (4)	0.0059 (4)	0.0013 (5)
C2	0.0193 (5)	0.0218 (5)	0.0270 (6)	0.0006 (4)	0.0039 (4)	0.0022 (4)
C3	0.0224 (6)	0.0303 (6)	0.0272 (6)	0.0003 (5)	−0.0008 (5)	−0.0012 (5)
C4	0.0312 (7)	0.0337 (7)	0.0259 (6)	0.0040 (6)	0.0048 (5)	−0.0022 (5)
C5	0.0236 (6)	0.0332 (7)	0.0317 (6)	0.0046 (5)	0.0086 (5)	0.0055 (5)
C6	0.0207 (6)	0.0367 (7)	0.0351 (7)	−0.0048 (5)	0.0038 (5)	−0.0002 (6)
C7	0.0234 (6)	0.0308 (6)	0.0274 (6)	−0.0050 (5)	0.0048 (5)	−0.0036 (5)
C8	0.0316 (8)	0.0576 (11)	0.0417 (8)	0.0079 (7)	0.0152 (6)	0.0035 (7)
C9	0.0318 (6)	0.0211 (6)	0.0349 (7)	−0.0002 (5)	0.0137 (5)	0.0036 (5)
C10	0.0332 (7)	0.0210 (6)	0.0321 (7)	0.0016 (5)	0.0141 (5)	−0.0009 (5)

Geometric parameters (Å, º) top

Co1—O1	2.0551 (9)	C2—C1	1.5093 (17)
Co1—O1ⁱ	2.0551 (9)	C2—C3	1.3911 (18)
Co1—O4	2.1491 (11)	C2—C7	1.3961 (17)
Co1—O4ⁱ	2.1491 (11)	C3—H3	0.9300
Co1—N1	2.1588 (15)	C4—C3	1.3884 (18)
Co1—N2ⁱⁱ	2.1714 (15)	C4—H4	0.9300
O1—C1	1.2721 (16)	C5—C4	1.390 (2)
O2—C1	1.2451 (17)	C5—C6	1.391 (2)
O3—C8	1.205 (2)	C5—C8	1.478 (2)
O4—H41	0.89 (3)	C6—H6	0.9300
O4—H42	0.71 (3)	C7—C6	1.3836 (18)
N1—C9	1.3357 (15)	C7—H7	0.9300
N1—C9ⁱ	1.3357 (15)	C8—H8	0.984 (13)
N2—Co1ⁱⁱⁱ	2.1714 (15)	C9—H9	0.9300
N2—C10	1.3347 (15)	C10—C9	1.3866 (19)
N2—C10ⁱ	1.3347 (15)	C10—H10	0.9300

O1—Co1—O1ⁱ	178.75 (5)	C3—C2—C1	120.92 (11)
O1—Co1—O4	91.46 (4)	C3—C2—C7	119.58 (12)
O1ⁱ—Co1—O4	88.60 (4)	C7—C2—C1	119.46 (11)
O1—Co1—O4ⁱ	88.60 (4)	C2—C3—H3	120.0
O1ⁱ—Co1—O4ⁱ	91.46 (4)	C4—C3—C2	119.94 (12)
O1—Co1—N1	89.38 (3)	C4—C3—H3	120.0
O1ⁱ—Co1—N1	89.38 (3)	C3—C4—C5	120.15 (13)
O1—Co1—N2ⁱⁱ	90.62 (3)	C3—C4—H4	119.9
O1ⁱ—Co1—N2ⁱⁱ	90.62 (3)	C5—C4—H4	119.9
O4—Co1—O4ⁱ	174.09 (7)	C4—C5—C6	120.13 (12)
O4—Co1—N1	92.96 (4)	C4—C5—C8	119.41 (14)
O4ⁱ—Co1—N1	92.96 (4)	C6—C5—C8	120.46 (14)
O4—Co1—N2ⁱⁱ	87.04 (4)	C5—C6—H6	120.2
O4ⁱ—Co1—N2ⁱⁱ	87.04 (4)	C7—C6—C5	119.67 (12)
N1—Co1—N2ⁱⁱ	180.000 (1)	C7—C6—H6	120.2
C1—O1—Co1	125.81 (9)	C2—C7—H7	119.7
Co1—O4—H41	96.6 (15)	C6—C7—C2	120.52 (12)
Co1—O4—H42	118 (2)	C6—C7—H7	119.7
H41—O4—H42	105 (3)	O3—C8—C5	125.34 (17)
C9—N1—Co1	121.75 (8)	O3—C8—H8	114.5 (10)
C9ⁱ—N1—Co1	121.75 (8)	C5—C8—H8	120.1 (10)
C9—N1—C9ⁱ	116.49 (15)	N1—C9—C10	121.79 (12)
C10—N2—Co1ⁱⁱⁱ	121.61 (8)	N1—C9—H9	119.1
C10ⁱ—N2—Co1ⁱⁱⁱ	121.61 (8)	C10—C9—H9	119.1
C10—N2—C10ⁱ	116.79 (15)	N2—C10—C9	121.57 (12)
O1—C1—C2	116.62 (11)	N2—C10—H10	119.2
O2—C1—O1	125.42 (12)	C9—C10—H10	119.2
O2—C1—C2	117.96 (11)

O4—Co1—O1—C1	23.45 (11)	C3—C2—C1—O1	7.53 (18)
O4ⁱ—Co1—O1—C1	−150.64 (11)	C3—C2—C1—O2	−171.75 (13)
N1—Co1—O1—C1	116.39 (10)	C7—C2—C1—O1	−174.80 (12)
N2ⁱⁱ—Co1—O1—C1	−63.61 (10)	C7—C2—C1—O2	5.92 (18)
O1—Co1—N1—C9	35.39 (8)	C1—C2—C3—C4	176.79 (12)
O1ⁱ—Co1—N1—C9	−144.61 (8)	C7—C2—C3—C4	−0.9 (2)
O1—Co1—N1—C9ⁱ	−144.61 (8)	C1—C2—C7—C6	−176.64 (12)
O1ⁱ—Co1—N1—C9ⁱ	35.39 (8)	C3—C2—C7—C6	1.1 (2)
O4—Co1—N1—C9	126.82 (8)	C5—C4—C3—C2	−0.1 (2)
O4ⁱ—Co1—N1—C9	−53.18 (8)	C4—C5—C6—C7	−0.8 (2)
O4—Co1—N1—C9ⁱ	−53.18 (8)	C6—C5—C4—C3	1.0 (2)
O4ⁱ—Co1—N1—C9ⁱ	126.82 (8)	C8—C5—C4—C3	−179.86 (14)
Co1—O1—C1—O2	−3.6 (2)	C8—C5—C6—C7	−179.95 (14)
Co1—O1—C1—C2	177.23 (8)	C4—C5—C8—O3	−172.93 (18)
Co1—N1—C9—C10	179.66 (10)	C6—C5—C8—O3	6.3 (3)
C9ⁱ—N1—C9—C10	−0.34 (10)	C2—C7—C6—C5	−0.2 (2)
Co1ⁱⁱⁱ—N2—C10—C9	179.66 (10)	N2—C10—C9—N1	0.7 (2)
C10ⁱ—N2—C10—C9	−0.34 (10)

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

Hydrogen-bond geometry (Å, º) top

Cg1 is the centroid of ring A (C2–C7).

D—H···A	D—H	H···A	D···A	D—H···A
O4—H41···O2	0.89 (3)	1.72 (3)	2.5909 (16)	164 (2)
O4—H42···O4^iv	0.71 (3)	2.63 (3)	2.958 (2)	111 (2)
C10—H10···O3^v	0.93	2.46	3.320 (2)	154
C7—H7···Cg1^vi	0.93	2.65	3.4216 (15)	142

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

Acknowledgements

The authors acknowledge the Aksaray University Science and Technology Application and Research Center, Aksaray, Turkey, for the use of the Bruker SMART BREEZE CCD diffractometer (purchased under grant No. 2010K120480 of the State of Planning Organization). This work was supported financially by the Kafkas University Research Fund (grant No. 2012-FEF-12).

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