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Acta Crystallogr Sect E Struct Rep Online. 2008 June 1; 64(Pt 6): m833.
Published online 2008 May 21. doi:  10.1107/S1600536808001220
PMCID: PMC2961466

Bis[(4-bromo­benzoyl­meth­yl)triphenyl­phospho­nium] di-μ-bromido-bis­[di­bromido­mercurate(IV)]

Abstract

Colourless needle-shaped crystals of the title compound, (C26H21BrOP)2[Hg2Br6], have been prepared by addition of a solution of HgBr2 in methanol to a solution of (4-bromo­benzoyl­meth­yl)triphenyl­phospho­rane in dry methanol. The compound features Hg2Br6 2− dianions, whose site symmetry is An external file that holds a picture, illustration, etc.
Object name is e-64-0m833-efi1.jpg.

Related literature

For other hexa­bromo­dimercurates, see: Bell et al. (2002 [triangle]); Fábry & Maximov (1991 [triangle]); Pickardt & Wischlinski (1999 [triangle]). For related literature, see: Hu et al. (2003 [triangle]); Nockemann & Meyer (2002 [triangle]); Sabounchei et al. (2007 [triangle]); Thiel et al. (1994 [triangle]).

An external file that holds a picture, illustration, etc.
Object name is e-64-0m833-scheme1.jpg

Experimental

Crystal data

  • (C26H21BrOP)2[Hg2Br6]
  • M r = 1801.18
  • Monoclinic, An external file that holds a picture, illustration, etc.
Object name is e-64-0m833-efi2.jpg
  • a = 9.4146 (6) Å
  • b = 21.8848 (14) Å
  • c = 13.2675 (9) Å
  • β = 100.785 (5)°
  • V = 2685.3 (3) Å3
  • Z = 2
  • Mo Kα radiation
  • μ = 11.76 mm−1
  • T = 120 (2) K
  • 0.5 × 0.12 × 0.1 mm

Data collection

  • Stoe IPDSII diffractometer
  • Absorption correction: numerical [shape of crystal determined optically (X-SHAPE; Stoe & Cie, 2005) T min = 0.200, T max = 0.300
  • 19321 measured reflections
  • 6386 independent reflections
  • 5929 reflections with I > 2σ(I)
  • R int = 0.063

Refinement

  • R[F 2 > 2σ(F 2)] = 0.032
  • wR(F 2) = 0.076
  • S = 1.17
  • 6386 reflections
  • 298 parameters
  • H-atom parameters constrained
  • Δρmax = 1.64 e Å−3
  • Δρmin = −1.32 e Å−3

Data collection: X-AREA (Stoe & Cie, 2005 [triangle]); cell refinement: X-AREA; data reduction: X-AREA; program(s) used to solve structure: SHELXS97 (Sheldrick, 2008 [triangle]); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008 [triangle]); molecular graphics: ORTEP-3 (Farrugia, 1997 [triangle]); software used to prepare material for publication: WinGX (Farrugia, 1999 [triangle]).

Supplementary Material

Crystal structure: contains datablocks global, I. DOI: 10.1107/S1600536808001220/fi2042sup1.cif

Structure factors: contains datablocks I. DOI: 10.1107/S1600536808001220/fi2042Isup2.hkl

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

Acknowledgments

The authors acknowledge Bu-Ali Sina University for financial support.

supplementary crystallographic information

Comment

Colourless, needle-shaped crystals of C26H21HgBr3OP were obtained from a mixture of methanol, dmso and diethyl ether. The crystal structure consists of discrete [BrC6H4COCH2PPh3]+ cations and [Hg2Br6]2- anions (Fig. 1). The crystals are air-stable and resistant to moisture. All atoms occupy general position in the monoclinic space group, P21/n. The site symmetry of the anion is -1, with the inversion centre halfway between the two Hg atoms. Comparison of the bond lengths and bond angles within the above crystal show that the phosphonium as a ligand is electrostatically under the influence of an anionic part of an bromomercurate in the unit cells (for instance the bond lengths C6—C7, O1—C7, C8—P1 and P1—C9 and bond angles C8—P1—C9, O1—C7—C8 are 1.489 (5), 1.213 (5), 1.804 (4) and 1.800 (4) A° and 106.7 (2) and 120.4 (4)° for title compound and 1.514 (2), 1.256 (2), 1.719 (2) and 1.805 (2) A° and 105.3 (1) and 123.2 (2)° for the phosphorane molecule (Sabounchei et al., 2007)). The bridging Hg—Br bond lengths in the crystal are 2.6693 (4) A° and 2.7920 (4) A°, the terminal Hg—Br distances are 2.5192 (5) A° and 2.5433 (5) A°. These values are well within the reported bond distances (2.703—-2.787 A° for bridging bromide and 2.479–2.532 A° for terminal bromide) in [Hg2Br6]-2 anions (Nockemann & Meyer, 2002; Thiel et al., 1994; Hu et al., 2003).

Experimental

Starting materials were purchased from commercial sources and used without further purification.The title compound was prepared by addition of solution of HgBr2 (0.18 g, 0.5 mmol) in methanol (15 ml) to a solution of the 4-bromobenzoylmethylenetriphenylphosphorane (0.229?g, 0.5?mmol) in dry methanol (15 ml) and stirring for 12 h. A white product formed upon slow evaporation ofthe solvent. It was washed several times with dry diethylether and dried invacuo. The product was then washed with benzene and dried in vacuo. Yield 83%, m.p=290 K. It was recrystallized from a mixture of methanol, dimethylsulfoxide and diethyl ether (1:1:3).

Refinement

All H atoms were positioned geometrically and refined using a riding model, Uiso=1.2Ueq of the respective carrier atom. The largest difference peak and hole (1.64 and -1.32 e.A-3) are found 1.18Å and 0.05Å respectively from Hg.

Figures

Fig. 1.
View of (I) (30% probability displacement ellipsoids), symmetry code (i)1 - x,-y,2 - z.

Crystal data

(C26H21BrOP)2[Hg2Br6]F000 = 1680
Mr = 1801.18Dx = 2.228 Mg m3
Monoclinic, P21/nMo Kα radiation λ = 0.71073 Å
Hall symbol: -P 2ynCell parameters from 2500 reflections
a = 9.4146 (6) Åθ = 1.8–28.0º
b = 21.8848 (14) ŵ = 11.76 mm1
c = 13.2675 (9) ÅT = 120 (2) K
β = 100.785 (5)ºNeedle, colourless
V = 2685.3 (3) Å30.5 × 0.12 × 0.1 mm
Z = 2

Data collection

Stoe IPDSII diffractometerRint = 0.063
ω scanθmax = 28.0º
Absorption correction: numerical(shape of crystal determined optically)θmin = 1.8º
Tmin = 0.200, Tmax = 0.300h = −12→12
19321 measured reflectionsk = −27→28
6386 independent reflectionsl = −17→17
5929 reflections with I > 2σ(I)

Refinement

Refinement on F2H-atom parameters constrained
Least-squares matrix: full  w = 1/[σ2(Fo2) + (0.0312P)2 + 4.7097P] where P = (Fo2 + 2Fc2)/3
R[F2 > 2σ(F2)] = 0.032(Δ/σ)max = 0.018
wR(F2) = 0.076Δρmax = 1.64 e Å3
S = 1.17Δρmin = −1.32 e Å3
6386 reflectionsExtinction correction: none
298 parameters

Special details

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.

Fractional atomic coordinates and isotropic or equivalent isotropic displacement parameters (Å2)

xyzUiso*/Ueq
Hg10.459203 (16)0.045660 (7)0.872826 (12)0.02046 (6)
Br1−0.20000 (5)0.01733 (2)0.54508 (3)0.02701 (10)
Br20.41038 (4)0.160021 (18)0.86866 (3)0.02001 (9)
Br30.70223 (4)0.011883 (18)0.99824 (3)0.01917 (9)
Br40.39811 (5)−0.00959 (2)0.70367 (3)0.02576 (10)
C10.0365 (4)0.0819 (2)0.8196 (3)0.0216 (8)
H10.13210.08080.8540.026*
C2−0.0011 (4)0.0538 (2)0.7241 (3)0.0230 (8)
H20.06860.0350.69360.028*
C3−0.1454 (4)0.05466 (19)0.6753 (3)0.0196 (8)
C4−0.2511 (4)0.08368 (19)0.7184 (3)0.0196 (8)
H4−0.34690.08390.68450.024*
C5−0.2114 (4)0.11225 (18)0.8126 (3)0.0176 (7)
H5−0.28120.13210.84170.021*
C6−0.0678 (4)0.11159 (17)0.8644 (3)0.0146 (7)
C7−0.0321 (4)0.14202 (18)0.9665 (3)0.0176 (7)
C80.1241 (4)0.13891 (19)1.0237 (3)0.0175 (7)
H8A0.18810.14310.97460.021*
H8B0.14130.09911.05560.021*
C90.3623 (4)0.20382 (18)1.1473 (3)0.0150 (7)
C100.4485 (4)0.15232 (18)1.1426 (3)0.0183 (7)
H100.40620.11421.12750.022*
C110.5986 (4)0.1587 (2)1.1606 (3)0.0207 (8)
H110.65670.12481.1560.025*
C120.6615 (4)0.2155 (2)1.1854 (3)0.0234 (8)
H120.76170.21941.19830.028*
C130.5753 (4)0.2667 (2)1.1912 (3)0.0228 (8)
H130.61770.30451.20870.027*
C140.4254 (4)0.26093 (19)1.1708 (3)0.0205 (8)
H140.36750.29511.17290.025*
C150.1055 (4)0.17780 (19)1.2365 (3)0.0172 (7)
C160.0059 (4)0.1308 (2)1.2391 (3)0.0233 (8)
H16−0.02860.10791.18050.028*
C17−0.0408 (5)0.1186 (2)1.3301 (4)0.0300 (10)
H17−0.10670.08731.33260.036*
C180.0096 (5)0.1526 (2)1.4175 (4)0.0303 (10)
H18−0.02340.14421.47780.036*
C190.1093 (5)0.1993 (2)1.4156 (3)0.0266 (9)
H190.14290.22211.47430.032*
C200.1586 (5)0.21153 (19)1.3246 (3)0.0213 (8)
H200.22670.24211.32290.026*
C210.0937 (4)0.26785 (17)1.0688 (3)0.0153 (7)
C22−0.0084 (4)0.29971 (18)1.1122 (3)0.0175 (7)
H22−0.03560.28551.17180.021*
C23−0.0689 (4)0.3527 (2)1.0657 (3)0.0223 (8)
H23−0.13740.37391.09420.027*
C24−0.0282 (5)0.3743 (2)0.9772 (4)0.0261 (9)
H24−0.06930.410.94670.031*
C250.0741 (5)0.3429 (2)0.9334 (4)0.0285 (9)
H250.10110.35750.8740.034*
C260.1351 (5)0.2896 (2)0.9792 (3)0.0241 (8)
H260.20330.26840.95050.029*
P10.16840 (10)0.19701 (4)1.12096 (7)0.01362 (18)
O1−0.1233 (3)0.16804 (15)1.0042 (2)0.0243 (6)

Atomic displacement parameters (Å2)

U11U22U33U12U13U23
Hg10.02434 (9)0.01809 (8)0.01816 (9)0.00154 (5)0.00193 (6)0.00013 (5)
Br10.0272 (2)0.0325 (2)0.0190 (2)−0.00427 (17)−0.00171 (15)−0.00519 (16)
Br20.02090 (18)0.01773 (18)0.0232 (2)0.00194 (14)0.00861 (14)0.00331 (14)
Br30.01555 (16)0.01933 (19)0.02263 (19)0.00089 (13)0.00359 (14)0.00510 (14)
Br40.0335 (2)0.0234 (2)0.01901 (19)−0.00529 (16)0.00126 (16)−0.00361 (15)
C10.0133 (16)0.027 (2)0.023 (2)0.0043 (15)−0.0005 (14)−0.0037 (16)
C20.0169 (17)0.026 (2)0.025 (2)0.0005 (15)0.0016 (15)−0.0049 (17)
C30.0219 (18)0.0197 (19)0.0151 (18)−0.0015 (15)−0.0020 (14)0.0027 (14)
C40.0138 (16)0.0213 (19)0.0213 (19)−0.0041 (14)−0.0027 (14)0.0033 (15)
C50.0136 (15)0.0174 (18)0.0217 (19)0.0001 (14)0.0031 (14)0.0062 (15)
C60.0091 (14)0.0137 (17)0.0203 (19)0.0008 (12)0.0008 (13)0.0006 (14)
C70.0155 (16)0.0161 (17)0.0212 (19)−0.0022 (13)0.0035 (14)−0.0011 (14)
C80.0168 (17)0.0197 (18)0.0160 (17)0.0009 (14)0.0030 (13)−0.0059 (15)
C90.0123 (15)0.0192 (18)0.0135 (17)−0.0002 (13)0.0019 (12)−0.0010 (14)
C100.0176 (17)0.0163 (18)0.0195 (19)−0.0009 (14)−0.0007 (14)−0.0006 (14)
C110.0154 (17)0.021 (2)0.025 (2)0.0031 (14)0.0026 (15)−0.0004 (16)
C120.0136 (16)0.027 (2)0.029 (2)−0.0018 (15)0.0026 (15)0.0024 (17)
C130.0189 (18)0.020 (2)0.028 (2)−0.0063 (15)0.0030 (15)−0.0041 (16)
C140.0195 (18)0.0180 (19)0.024 (2)0.0000 (15)0.0036 (15)−0.0033 (15)
C150.0137 (16)0.0192 (18)0.0195 (18)0.0022 (14)0.0055 (13)0.0012 (14)
C160.0206 (18)0.024 (2)0.025 (2)−0.0014 (15)0.0035 (16)0.0023 (16)
C170.024 (2)0.029 (2)0.039 (3)−0.0019 (17)0.0095 (18)0.013 (2)
C180.032 (2)0.036 (3)0.026 (2)0.0083 (19)0.0124 (18)0.0119 (19)
C190.033 (2)0.030 (2)0.018 (2)0.0100 (18)0.0087 (17)0.0020 (17)
C200.0246 (19)0.0178 (18)0.021 (2)0.0005 (15)0.0045 (15)0.0012 (15)
C210.0146 (15)0.0132 (16)0.0176 (18)−0.0013 (13)0.0022 (13)−0.0003 (14)
C220.0163 (16)0.0171 (18)0.0190 (18)−0.0015 (14)0.0031 (14)−0.0011 (14)
C230.0180 (17)0.021 (2)0.027 (2)0.0036 (15)0.0021 (15)−0.0024 (17)
C240.026 (2)0.022 (2)0.027 (2)0.0052 (16)−0.0022 (17)0.0054 (17)
C250.035 (2)0.028 (2)0.024 (2)0.0027 (19)0.0077 (18)0.0090 (18)
C260.030 (2)0.021 (2)0.023 (2)0.0024 (17)0.0095 (17)0.0018 (16)
P10.0123 (4)0.0141 (4)0.0147 (4)0.0004 (3)0.0032 (3)−0.0015 (3)
O10.0159 (13)0.0271 (16)0.0300 (16)0.0008 (11)0.0050 (11)−0.0085 (13)

Geometric parameters (Å, °)

Hg1—Br42.5192 (5)C12—C131.394 (6)
Hg1—Br22.5433 (5)C12—H120.93
Hg1—Br32.6693 (4)C13—C141.391 (5)
Hg1—Br3i2.7919 (4)C13—H130.93
Br1—C31.893 (4)C14—H140.93
Br3—Hg1i2.7919 (4)C15—C201.394 (6)
C1—C21.392 (6)C15—C161.396 (6)
C1—C61.400 (5)C15—P11.794 (4)
C1—H10.93C16—C171.386 (6)
C2—C31.391 (6)C16—H160.93
C2—H20.93C17—C181.384 (8)
C3—C41.391 (6)C17—H170.93
C4—C51.385 (6)C18—C191.389 (7)
C4—H40.93C18—H180.93
C5—C61.398 (5)C19—C201.397 (6)
C5—H50.93C19—H190.93
C6—C71.489 (5)C20—H200.93
C7—O11.213 (5)C21—C221.395 (5)
C7—C81.526 (5)C21—C261.403 (6)
C8—P11.804 (4)C21—P11.787 (4)
C8—H8A0.97C22—C231.384 (6)
C8—H8B0.97C22—H220.93
C9—C141.394 (6)C23—C241.386 (6)
C9—C101.397 (5)C23—H230.93
C9—P11.800 (4)C24—C251.395 (7)
C10—C111.396 (5)C24—H240.93
C10—H100.93C25—C261.388 (6)
C11—C121.391 (6)C25—H250.93
C11—H110.93C26—H260.93
Br4—Hg1—Br2116.277 (15)C14—C13—H13120.1
Br4—Hg1—Br3116.655 (15)C12—C13—H13120.1
Br2—Hg1—Br3114.607 (14)C13—C14—C9119.9 (4)
Br4—Hg1—Br3i105.642 (15)C13—C14—H14120
Br2—Hg1—Br3i109.895 (13)C9—C14—H14120
Br3—Hg1—Br3i89.686 (12)C20—C15—C16120.4 (4)
Hg1—Br3—Hg1i90.314 (12)C20—C15—P1117.9 (3)
C2—C1—C6120.8 (4)C16—C15—P1121.6 (3)
C2—C1—H1119.6C17—C16—C15119.1 (4)
C6—C1—H1119.6C17—C16—H16120.4
C3—C2—C1118.5 (4)C15—C16—H16120.4
C3—C2—H2120.7C18—C17—C16120.8 (4)
C1—C2—H2120.7C18—C17—H17119.6
C4—C3—C2121.7 (4)C16—C17—H17119.6
C4—C3—Br1118.6 (3)C17—C18—C19120.4 (4)
C2—C3—Br1119.6 (3)C17—C18—H18119.8
C5—C4—C3119.0 (3)C19—C18—H18119.8
C5—C4—H4120.5C18—C19—C20119.4 (4)
C3—C4—H4120.5C18—C19—H19120.3
C4—C5—C6120.8 (4)C20—C19—H19120.3
C4—C5—H5119.6C15—C20—C19119.8 (4)
C6—C5—H5119.6C15—C20—H20120.1
C5—C6—C1119.1 (4)C19—C20—H20120.1
C5—C6—C7118.4 (3)C22—C21—C26120.1 (4)
C1—C6—C7122.5 (3)C22—C21—P1121.7 (3)
O1—C7—C6121.9 (3)C26—C21—P1118.1 (3)
O1—C7—C8120.4 (4)C23—C22—C21119.5 (4)
C6—C7—C8117.7 (3)C23—C22—H22120.2
C7—C8—P1113.4 (3)C21—C22—H22120.2
C7—C8—H8A108.9C22—C23—C24120.5 (4)
P1—C8—H8A108.9C22—C23—H23119.8
C7—C8—H8B108.9C24—C23—H23119.8
P1—C8—H8B108.9C23—C24—C25120.5 (4)
H8A—C8—H8B107.7C23—C24—H24119.8
C14—C9—C10120.4 (3)C25—C24—H24119.8
C14—C9—P1119.5 (3)C26—C25—C24119.5 (4)
C10—C9—P1120.1 (3)C26—C25—H25120.2
C11—C10—C9119.4 (4)C24—C25—H25120.2
C11—C10—H10120.3C25—C26—C21119.9 (4)
C9—C10—H10120.3C25—C26—H26120
C12—C11—C10120.1 (4)C21—C26—H26120
C12—C11—H11119.9C21—P1—C15111.40 (18)
C10—C11—H11119.9C21—P1—C9108.34 (18)
C11—C12—C13120.4 (4)C15—P1—C9109.79 (17)
C11—C12—H12119.8C21—P1—C8108.25 (18)
C13—C12—H12119.8C15—P1—C8112.16 (19)
C14—C13—C12119.8 (4)C9—P1—C8106.72 (17)
Br4—Hg1—Br3—Hg1i−107.394 (16)C16—C15—C20—C19−1.6 (6)
Br2—Hg1—Br3—Hg1i111.825 (14)P1—C15—C20—C19178.2 (3)
Br3i—Hg1—Br3—Hg1i0C18—C19—C20—C151.2 (6)
C6—C1—C2—C3−1.6 (7)C26—C21—C22—C230.3 (6)
C1—C2—C3—C41.4 (7)P1—C21—C22—C23−176.5 (3)
C1—C2—C3—Br1179.7 (3)C21—C22—C23—C24−0.4 (6)
C2—C3—C4—C5−0.3 (6)C22—C23—C24—C250.2 (7)
Br1—C3—C4—C5−178.6 (3)C23—C24—C25—C260.0 (7)
C3—C4—C5—C6−0.6 (6)C24—C25—C26—C210.0 (7)
C4—C5—C6—C10.4 (6)C22—C21—C26—C25−0.2 (6)
C4—C5—C6—C7−178.8 (4)P1—C21—C26—C25176.8 (4)
C2—C1—C6—C50.7 (6)C22—C21—P1—C15−4.3 (4)
C2—C1—C6—C7179.9 (4)C26—C21—P1—C15178.8 (3)
C5—C6—C7—O1−1.4 (6)C22—C21—P1—C9−125.2 (3)
C1—C6—C7—O1179.4 (4)C26—C21—P1—C957.9 (4)
C5—C6—C7—C8177.9 (4)C22—C21—P1—C8119.5 (3)
C1—C6—C7—C8−1.3 (6)C26—C21—P1—C8−57.4 (4)
O1—C7—C8—P1−20.7 (5)C20—C15—P1—C21−72.1 (3)
C6—C7—C8—P1160.0 (3)C16—C15—P1—C21107.6 (3)
C14—C9—C10—C11−0.6 (6)C20—C15—P1—C947.9 (4)
P1—C9—C10—C11178.3 (3)C16—C15—P1—C9−132.4 (3)
C9—C10—C11—C121.5 (6)C20—C15—P1—C8166.4 (3)
C10—C11—C12—C13−0.8 (7)C16—C15—P1—C8−13.9 (4)
C11—C12—C13—C14−0.8 (7)C14—C9—P1—C2128.6 (4)
C12—C13—C14—C91.7 (7)C10—C9—P1—C21−150.4 (3)
C10—C9—C14—C13−1.0 (6)C14—C9—P1—C15−93.3 (3)
P1—C9—C14—C13−179.9 (3)C10—C9—P1—C1587.7 (4)
C20—C15—C16—C170.8 (6)C14—C9—P1—C8144.9 (3)
P1—C15—C16—C17−178.9 (3)C10—C9—P1—C8−34.1 (4)
C15—C16—C17—C180.3 (7)C7—C8—P1—C21−43.9 (3)
C16—C17—C18—C19−0.7 (7)C7—C8—P1—C1579.4 (3)
C17—C18—C19—C20−0.1 (7)C7—C8—P1—C9−160.3 (3)

Symmetry codes: (i) −x+1, −y, −z+2.

Footnotes

Supplementary data and figures for this paper are available from the IUCr electronic archives (Reference: FI2042).

References

  • Bell, N. A., Coles, S. J., Constable, C. P., Hursthouse, M. B., Light, M. E., Mansor, R. & Salvin, N. J. (2002). Polyhedron, 21, 1845–1855.
  • Fábry, J. & Maximov, B. A. (1991). Acta Cryst. C47, 51–53.
  • Farrugia, L. J. (1997). J. Appl. Cryst.30, 565.
  • Farrugia, L. J. (1999). J. Appl. Cryst.32, 837–838.
  • Hu, N., Norifusa, T. & Aoki, K. (2003). Dalton Trans. pp. 335–341.
  • Nockemann, P. & Meyer, G. (2002). Acta Cryst. E58, m529–m530.
  • Pickardt, J. & Wischlinski, P. (1999). Z. Anorg. Allg. Chem 625, 1527–1531.
  • Sabounchei, S. J., Dadras, A., Jafarzadeh, M. & Khavasi, H. R. (2007). Acta Cryst. E63, o3160.
  • Sheldrick, G. M. (2008). Acta Cryst. A64, 112–122. [PubMed]
  • Stoe & Cie (2005). X-AREA and X-SHAPE Stoe & Cie GmbH, Darmstadt, Germany.
  • Thiel, J., Bu, X. & Coppens, P. (1994). Acta Cryst. C50, 23–25.

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