A triclinic polymorph with Z = 3 of N,N′-bis­(2-pyrid­yl)oxamide

Zhang, W.-J.; Wang, F.; Zhang, G.-L.; Xiao, X.

doi:10.1107/S1600536811010294

organic compounds

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ISSN: 2056-9890

Volume 67| Part 4| April 2011| Pages o972-o973

doi:10.1107/S1600536811010294

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A triclinic polymorph with Z = 3 of N,N′-bis(2-pyridyl)oxamide

Wan-Ju Zhang,^a Fang Wang,^a ^* Gui-Ling Zhang ^b and Xin Xiao ^c

^aSchool of Chemical Engineering, Huanggang Normal University, 438000 Huanggang, People's Republic of China, ^bExperimental Center, Guiyang University, 550005 Guiyang, People's Republic of China, and ^cInstitute of Applied Chemistry, Guizhou University, 550025 Guiyang, People's Republic of China
^*Correspondence e-mail: wangfang198107@hotmail.com

(Received 12 February 2011; accepted 18 March 2011; online 26 March 2011)

The asymmetric unit of the title compound, C₁₂H₁₀N₄O₂, contains three half-molecules. Each half-molecule is completed by crystallographic inversion symmetry. The title compound, (I), is a polymorph of the structure, (II), reported by Hsu & Chen [Eur. J. Inorg. Chem. (2004), 1488–1493]. In the original report, the compound crystallized in the tetragonal space group P $[\overline{4}]$ 2₁c (Z = 8), whereas the structure reported here is triclinic (P $[\overline{1}]$ , Z = 3). In both forms, each oxamide molecule is almost planar (with maximum deviations are 0.266 and 0.166 Å) and the O atoms are trans oriented. The principal difference between the two forms lies in the different hydrogen-bonding patterns. In (I), two N—H⋯O and one N—H⋯N hydrogen bonds link the molecules, forming a two-dimensional network, whereas in (II) there are no classical hydrogen bonds to O atoms and only weak C—H⋯O interactions are found along with rings of N—H⋯N bonds.

Related literature

For general background to the use of N,N′-disubstituted oxamides as ligands, see: Bencini et al. (1986 ). For the synthesis and related structure, see: Hsu & Chen (2004 ).

Experimental

Crystal data

C₁₂H₁₀N₄O₂
M_r = 242.24
Triclinic, $[P \overline 1]$
a = 8.459 (2) Å
b = 10.705 (3) Å
c = 11.058 (3) Å
α = 99.555 (9)°
β = 101.344 (8)°
γ = 112.980 (8)°
V = 870.5 (4) Å³
Z = 3
Mo Kα radiation
μ = 0.10 mm⁻¹
T = 298 K
0.26 × 0.26 × 0.20 mm

Data collection

Bruker SMART APEX CCD diffractometer
Absorption correction: multi-scan (SADABS; Sheldrick, 2003 ) T_min = 0.975, T_max = 0.980
8909 measured reflections
3018 independent reflections
2575 reflections with I > 2σ(I)
R_int = 0.021

Refinement

R[F² > 2σ(F²)] = 0.044
wR(F²) = 0.125
S = 1.07
3018 reflections
245 parameters
H-atom parameters constrained
Δρ_max = 0.24 e Å⁻³
Δρ_min = −0.34 e Å⁻³

Table 1
Hydrogen-bond geometry (Å, °)

D—H⋯A	D—H	H⋯A	D⋯A	D—H⋯A
N2—H2A⋯O3	0.86	2.39	3.176 (2)	153
N4—H4A⋯O3	0.86	2.27	2.898 (2)	130
N6—H6⋯N3ⁱ	0.86	2.39	3.188 (2)	155
Symmetry code: (i) -x+1, -y+1, -z+1.

Data collection: SMART (Bruker, 2002 ); cell refinement: SAINT (Bruker, 2002); data reduction: SAINT; program(s) used to solve structure: SHELXS97 (Sheldrick, 2008 ); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008); molecular graphics: XP (Siemens, 1994 ) and CAMERON (Watkin et al., 1993 ); software used to prepare material for publication: WinGX (Farrugia, 1999 ).

Supporting information

Crystal structure: contains datablocks global, I. DOI: 10.1107/S1600536811010294/ez2234sup1.cif

Structure factors: contains datablock I. DOI: 10.1107/S1600536811010294/ez2234Isup2.hkl

checkCIF report

Comment top

N,N'-disubstituted oxamides are known to be versatile organic ligands since their coordinating ability toward transition-metal ions can be modified and tuned by changing the nature of the amide substituents (Bencini et al., 1986). The title compound, (I), is a triclinic polymorph of the previously reported crystal structure of this symmetrical N,N'-disubstituted oxamide which crystallizes in the tetragonal space group P-42₁/c (Hsu & Chen, 2004). The relative arrangement of the molecules observed in the current structure is distinctively different from that previously reported.

The molecular structure of (I) is shown in Fig. 1. It crystallizes in the space group P-1 with three molecules in each unit cell. Each N,N'-di(2-pyridyl)oxamide molecule is almost planar and the O atoms are trans-oriented. In the crystal structure, classical N—H···O and N—H···N hydrogen bonds (Table 1, Fig. 2) link the molecules to form a two-dimensional network.

Related literature top

For general background to the use of N,N'-disubstituted oxamides as ligands, see: Bencini et al. (1986). For the synthesis and related structure, see: Hsu & Chen (2004).

Experimental top

2-Aminopyridine (4.7 g, 50 mmol) was dissolved in 200 ml CH₂Cl₂, followed by addition of triethyl amine (10.0 ml, 72.1 mmol) at 273 K. The mixture was then stirred for 10 min. Oxalyl chloride (2.2 ml, 25 mmol) in 10 ml CH₂Cl₂ was then added slowly to the above mixture. After continuous stirring for about 3 h at 273 K, the resulting solution was concentrated under vacuum until a large amount of solid precipitated. The solid was filtered, washed with water and then dried in vacuum. Yield: 4.3 g (71%). Colourless block crystals suitable for X-ray crystallography were obtained by slow evaporation of the solvent from a solution of the title compound in toluene.

Computing details top

Data collection: SMART (Bruker, 2002); cell refinement: SAINT (Bruker, 2002); data reduction: SAINT (Bruker, 2002); program(s) used to solve structure: SHELXL97 (Sheldrick, 2008); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008); molecular graphics: XP (Siemens, 1994) and CAMERON (Watkin et al., 1993); software used to prepare material for publication: WinGX (Farrugia, 1999).

Figures top

	Fig. 1. The molecular structure of (I), with atom labels and 30% probability displacement ellipsoids for non-H atoms. [symmetry codes: (i) -x + 1, -y, -z + 1; (ii) -x, -y, -z + 1; (iii) -x + 1, -y + 1, -z + 1.]
	Fig. 2. The two-dimensional hydrogen-bonded structure. Dashed lines indicate hydrogen bonds. H atoms not involved in hydrogen bonding were omitted for clarity. [symmetry code: (iii) -x + 1, -y + 1, -z + 1.]

N,N'-bis(pyridin-2-yl)ethanediamide top

Crystal data top

C₁₂H₁₀N₄O₂	Z = 3
M_r = 242.24	F(000) = 378
Triclinic, P1	D_x = 1.386 Mg m⁻³
Hall symbol: -p 1	Mo Kα radiation, λ = 0.71073 Å
a = 8.459 (2) Å	Cell parameters from 2575 reflections
b = 10.705 (3) Å	θ = 2.0–25.1°
c = 11.058 (3) Å	µ = 0.10 mm⁻¹
α = 99.555 (9)°	T = 298 K
β = 101.344 (8)°	Block, colourless
γ = 112.980 (8)°	0.26 × 0.26 × 0.20 mm
V = 870.5 (4) Å³

Data collection top

Bruker SMART APEX CCD diffractometer	3018 independent reflections
Radiation source: fine-focus sealed tube	2575 reflections with I > 2σ(I)
Graphite monochromator	R_int = 0.021
ϕ and ω scans	θ_max = 25.1°, θ_min = 2.0°
Absorption correction: multi-scan (SADABS; Sheldrick, 2003)	h = −10→9
T_min = 0.975, T_max = 0.980	k = −12→12
8909 measured reflections	l = −13→13

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)] = 0.044	Hydrogen site location: inferred from neighbouring sites
wR(F²) = 0.125	H-atom parameters constrained
S = 1.07	w = 1/[σ²(F_o²) + (0.0745P)² + 0.1649P] where P = (F_o² + 2F_c²)/3
3018 reflections	(Δ/σ)_max < 0.001
245 parameters	Δρ_max = 0.24 e Å⁻³
0 restraints	Δρ_min = −0.34 e Å⁻³

Crystal data top

C₁₂H₁₀N₄O₂	γ = 112.980 (8)°
M_r = 242.24	V = 870.5 (4) Å³
Triclinic, P1	Z = 3
a = 8.459 (2) Å	Mo Kα radiation
b = 10.705 (3) Å	µ = 0.10 mm⁻¹
c = 11.058 (3) Å	T = 298 K
α = 99.555 (9)°	0.26 × 0.26 × 0.20 mm
β = 101.344 (8)°

Data collection top

Bruker SMART APEX CCD diffractometer	3018 independent reflections
Absorption correction: multi-scan (SADABS; Sheldrick, 2003)	2575 reflections with I > 2σ(I)
T_min = 0.975, T_max = 0.980	R_int = 0.021
8909 measured reflections

Refinement top

R[F² > 2σ(F²)] = 0.044	0 restraints
wR(F²) = 0.125	H-atom parameters constrained
S = 1.07	Δρ_max = 0.24 e Å⁻³
3018 reflections	Δρ_min = −0.34 e Å⁻³
245 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
C1	0.8362 (2)	0.46853 (19)	0.37248 (18)	0.0520 (4)
H1	0.8499	0.5608	0.3908	0.062*
C2	0.9305 (2)	0.4331 (2)	0.29625 (17)	0.0530 (5)
H2	1.0085	0.5002	0.2655	0.064*
C3	0.9066 (3)	0.2958 (2)	0.26675 (17)	0.0557 (5)
H3	0.9672	0.2682	0.2144	0.067*
C4	0.7921 (3)	0.1992 (2)	0.31520 (17)	0.0525 (4)
H4	0.7732	0.1056	0.2957	0.063*
C5	0.7062 (2)	0.24577 (17)	0.39383 (15)	0.0413 (4)
C6	0.5610 (2)	0.02730 (17)	0.45799 (16)	0.0433 (4)
C7	0.2643 (3)	0.1234 (2)	0.11856 (19)	0.0686 (6)
H7	0.3133	0.2017	0.0881	0.082*
C8	0.2515 (4)	−0.0019 (2)	0.0534 (2)	0.0805 (7)
H8	0.2911	−0.0087	−0.0191	0.097*
C9	0.1791 (4)	−0.1164 (2)	0.0977 (2)	0.0880 (8)
H9	0.1681	−0.2033	0.0552	0.106*
C10	0.1222 (3)	−0.1038 (2)	0.20524 (19)	0.0662 (6)
H10	0.0731	−0.1809	0.2371	0.079*
C11	0.1405 (2)	0.02693 (16)	0.26431 (14)	0.0386 (4)
C12	0.0128 (2)	−0.03698 (15)	0.43944 (14)	0.0364 (3)
C13	0.7504 (3)	0.5115 (2)	0.97931 (17)	0.0646 (6)
H13	0.8479	0.5692	1.0504	0.078*
C14	0.6308 (3)	0.3874 (2)	0.99039 (17)	0.0631 (5)
H14	0.6460	0.3612	1.0664	0.076*
C15	0.4884 (3)	0.3032 (2)	0.88626 (18)	0.0660 (6)
H15	0.4042	0.2175	0.8901	0.079*
C16	0.4690 (3)	0.34467 (18)	0.77573 (16)	0.0521 (5)
H16	0.3719	0.2886	0.7040	0.063*
C17	0.5974 (2)	0.47196 (15)	0.77397 (13)	0.0347 (3)
C18	0.48440 (19)	0.45519 (14)	0.54712 (13)	0.0312 (3)
N1	0.72567 (19)	0.37762 (14)	0.42180 (14)	0.0472 (4)
N2	0.59256 (19)	0.15935 (14)	0.45411 (14)	0.0457 (4)
H2A	0.5362	0.1959	0.4934	0.055*
N3	0.2108 (2)	0.14008 (15)	0.22304 (13)	0.0505 (4)
N4	0.08990 (17)	0.05422 (13)	0.37520 (12)	0.0385 (3)
H4A	0.1109	0.1402	0.4060	0.046*
N5	0.7374 (2)	0.55612 (16)	0.87343 (13)	0.0531 (4)
N6	0.59098 (16)	0.52565 (12)	0.66636 (11)	0.0351 (3)
H6	0.6628	0.6127	0.6784	0.042*
O1	0.62022 (18)	−0.04585 (13)	0.40434 (13)	0.0584 (4)
O2	−0.03443 (16)	−0.16334 (11)	0.41046 (11)	0.0501 (3)
O3	0.37249 (15)	0.33253 (10)	0.51223 (9)	0.0415 (3)

Atomic displacement parameters (Å²) top

	U¹¹	U²²	U³³	U¹²	U¹³	U²³
C1	0.0499 (10)	0.0450 (10)	0.0644 (11)	0.0197 (8)	0.0202 (9)	0.0213 (8)
C2	0.0461 (10)	0.0640 (12)	0.0538 (10)	0.0229 (9)	0.0177 (8)	0.0273 (9)
C3	0.0585 (11)	0.0729 (13)	0.0507 (10)	0.0377 (10)	0.0235 (9)	0.0228 (9)
C4	0.0628 (11)	0.0524 (10)	0.0545 (10)	0.0336 (9)	0.0223 (9)	0.0177 (8)
C5	0.0377 (8)	0.0414 (9)	0.0461 (9)	0.0190 (7)	0.0099 (7)	0.0139 (7)
C6	0.0408 (9)	0.0362 (8)	0.0523 (9)	0.0183 (7)	0.0095 (7)	0.0116 (7)
C7	0.1028 (17)	0.0534 (11)	0.0552 (11)	0.0248 (11)	0.0486 (12)	0.0216 (9)
C8	0.123 (2)	0.0638 (13)	0.0675 (13)	0.0354 (13)	0.0651 (14)	0.0193 (11)
C9	0.144 (2)	0.0524 (12)	0.0840 (16)	0.0407 (14)	0.0736 (17)	0.0163 (11)
C10	0.1025 (16)	0.0397 (9)	0.0627 (12)	0.0248 (10)	0.0487 (12)	0.0162 (9)
C11	0.0413 (8)	0.0363 (8)	0.0350 (8)	0.0117 (7)	0.0144 (6)	0.0106 (6)
C12	0.0348 (8)	0.0306 (8)	0.0382 (8)	0.0075 (6)	0.0119 (6)	0.0110 (6)
C13	0.0660 (12)	0.0720 (13)	0.0381 (9)	0.0167 (10)	0.0012 (8)	0.0205 (9)
C14	0.0823 (14)	0.0694 (13)	0.0403 (10)	0.0300 (11)	0.0168 (9)	0.0304 (9)
C15	0.0864 (15)	0.0509 (11)	0.0469 (11)	0.0109 (10)	0.0205 (10)	0.0253 (9)
C16	0.0639 (11)	0.0433 (9)	0.0350 (8)	0.0078 (8)	0.0133 (8)	0.0149 (7)
C17	0.0420 (8)	0.0353 (8)	0.0308 (7)	0.0176 (7)	0.0145 (6)	0.0123 (6)
C18	0.0351 (7)	0.0296 (7)	0.0309 (7)	0.0125 (6)	0.0151 (6)	0.0104 (6)
N1	0.0447 (8)	0.0396 (8)	0.0619 (9)	0.0187 (6)	0.0209 (7)	0.0175 (7)
N2	0.0473 (8)	0.0368 (7)	0.0613 (9)	0.0224 (6)	0.0219 (7)	0.0164 (6)
N3	0.0719 (10)	0.0409 (8)	0.0412 (7)	0.0186 (7)	0.0299 (7)	0.0159 (6)
N4	0.0484 (8)	0.0292 (6)	0.0365 (7)	0.0121 (6)	0.0186 (6)	0.0102 (5)
N5	0.0540 (9)	0.0531 (9)	0.0366 (7)	0.0098 (7)	0.0052 (6)	0.0164 (6)
N6	0.0408 (7)	0.0291 (6)	0.0311 (6)	0.0088 (5)	0.0122 (5)	0.0112 (5)
O1	0.0672 (8)	0.0431 (7)	0.0791 (9)	0.0310 (6)	0.0337 (7)	0.0199 (6)
O2	0.0628 (8)	0.0309 (6)	0.0526 (7)	0.0104 (5)	0.0290 (6)	0.0117 (5)
O3	0.0489 (6)	0.0306 (6)	0.0343 (6)	0.0053 (5)	0.0129 (5)	0.0108 (4)

Geometric parameters (Å, º) top

C1—N1	1.336 (2)	C11—N3	1.326 (2)
C1—C2	1.373 (3)	C11—N4	1.399 (2)
C1—H1	0.9300	C12—O2	1.2149 (18)
C2—C3	1.375 (3)	C12—N4	1.3411 (18)
C2—H2	0.9300	C12—C12ⁱⁱ	1.537 (3)
C3—C4	1.378 (3)	C13—N5	1.337 (2)
C3—H3	0.9300	C13—C14	1.363 (3)
C4—C5	1.386 (2)	C13—H13	0.9300
C4—H4	0.9300	C14—C15	1.361 (3)
C5—N1	1.330 (2)	C14—H14	0.9300
C5—N2	1.410 (2)	C15—C16	1.370 (2)
C6—O1	1.219 (2)	C15—H15	0.9300
C6—N2	1.342 (2)	C16—C17	1.378 (2)
C6—C6ⁱ	1.535 (3)	C16—H16	0.9300
C7—N3	1.331 (2)	C17—N5	1.323 (2)
C7—C8	1.365 (3)	C17—N6	1.4054 (18)
C7—H7	0.9300	C18—O3	1.2193 (18)
C8—C9	1.360 (3)	C18—N6	1.3384 (19)
C8—H8	0.9300	C18—C18ⁱⁱⁱ	1.523 (3)
C9—C10	1.374 (3)	N2—H2A	0.8600
C9—H9	0.9300	N4—H4A	0.8600
C10—C11	1.377 (2)	N6—H6	0.8600
C10—H10	0.9300

N1—C1—C2	123.58 (17)	O2—C12—N4	126.93 (14)
N1—C1—H1	118.2	O2—C12—C12ⁱⁱ	121.30 (15)
C2—C1—H1	118.2	N4—C12—C12ⁱⁱ	111.77 (15)
C1—C2—C3	118.10 (17)	N5—C13—C14	124.56 (18)
C1—C2—H2	121.0	N5—C13—H13	117.7
C3—C2—H2	121.0	C14—C13—H13	117.7
C2—C3—C4	119.68 (17)	C15—C14—C13	117.60 (16)
C2—C3—H3	120.2	C15—C14—H14	121.2
C4—C3—H3	120.2	C13—C14—H14	121.2
C3—C4—C5	117.98 (17)	C14—C15—C16	119.96 (17)
C3—C4—H4	121.0	C14—C15—H15	120.0
C5—C4—H4	121.0	C16—C15—H15	120.0
N1—C5—C4	123.16 (15)	C15—C16—C17	118.07 (17)
N1—C5—N2	113.25 (14)	C15—C16—H16	121.0
C4—C5—N2	123.58 (15)	C17—C16—H16	121.0
O1—C6—N2	126.53 (16)	N5—C17—C16	123.44 (14)
O1—C6—C6ⁱ	120.90 (18)	N5—C17—N6	113.46 (13)
N2—C6—C6ⁱ	112.56 (18)	C16—C17—N6	123.09 (14)
N3—C7—C8	123.90 (18)	O3—C18—N6	126.12 (12)
N3—C7—H7	118.1	O3—C18—C18ⁱⁱⁱ	121.04 (16)
C8—C7—H7	118.1	N6—C18—C18ⁱⁱⁱ	112.84 (15)
C9—C8—C7	117.97 (19)	C5—N1—C1	117.47 (15)
C9—C8—H8	121.0	C6—N2—C5	128.27 (15)
C7—C8—H8	121.0	C6—N2—H2A	115.9
C8—C9—C10	120.0 (2)	C5—N2—H2A	115.9
C8—C9—H9	120.0	C11—N3—C7	117.05 (15)
C10—C9—H9	120.0	C12—N4—C11	128.10 (13)
C9—C10—C11	117.76 (17)	C12—N4—H4A	115.9
C9—C10—H10	121.1	C11—N4—H4A	115.9
C11—C10—H10	121.1	C17—N5—C13	116.37 (15)
N3—C11—C10	123.32 (15)	C18—N6—C17	126.63 (12)
N3—C11—N4	113.26 (14)	C18—N6—H6	116.7
C10—C11—N4	123.41 (14)	C17—N6—H6	116.7

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

Hydrogen-bond geometry (Å, º) top

D—H···A	D—H	H···A	D···A	D—H···A
N2—H2A···O3	0.86	2.39	3.176 (2)	153
N4—H4A···O3	0.86	2.27	2.898 (2)	130
N6—H6···N3ⁱⁱⁱ	0.86	2.39	3.188 (2)	155

Symmetry code: (iii) −x+1, −y+1, −z+1.

Experimental details

Crystal data
Chemical formula	C₁₂H₁₀N₄O₂
M_r	242.24
Crystal system, space group	Triclinic, P1
Temperature (K)	298
a, b, c (Å)	8.459 (2), 10.705 (3), 11.058 (3)
α, β, γ (°)	99.555 (9), 101.344 (8), 112.980 (8)
V (Å³)	870.5 (4)
Z	3
Radiation type	Mo Kα
µ (mm⁻¹)	0.10
Crystal size (mm)	0.26 × 0.26 × 0.20

Data collection
Diffractometer	Bruker SMART APEX CCD diffractometer
Absorption correction	Multi-scan (SADABS; Sheldrick, 2003)
T_min, T_max	0.975, 0.980
No. of measured, independent and observed [I > 2σ(I)] reflections	8909, 3018, 2575
R_int	0.021
(sin θ/λ)_max (Å⁻¹)	0.596

Refinement
R[F² > 2σ(F²)], wR(F²), S	0.044, 0.125, 1.07
No. of reflections	3018
No. of parameters	245
H-atom treatment	H-atom parameters constrained
Δρ_max, Δρ_min (e Å⁻³)	0.24, −0.34

Computer programs: SMART (Bruker, 2002), SAINT (Bruker, 2002), SHELXL97 (Sheldrick, 2008), XP (Siemens, 1994) and CAMERON (Watkin et al., 1993), WinGX (Farrugia, 1999).

Hydrogen-bond geometry (Å, º) top

D—H···A	D—H	H···A	D···A	D—H···A
N2—H2A···O3	0.86	2.39	3.176 (2)	153
N4—H4A···O3	0.86	2.27	2.898 (2)	130
N6—H6···N3ⁱ	0.86	2.39	3.188 (2)	155

Symmetry code: (i) −x+1, −y+1, −z+1.

Acknowledgements

The authors thank the Doctoral Foundation of Huanggang Normal University (No. 09CD157) for financial support.

References

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