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ISSN: 2056-9890

1-Benzyl-3-(2-meth­oxy­phen­yl)imidazolium tetra­fluoro­borate

aSchool of Chemistry and Chemical Engineering, China West Normal University, Nanchong 637002, People's Republic of China
*Correspondence e-mail: jphdp868@126.com

(Received 29 July 2009; accepted 11 August 2009; online 19 August 2009)

In the title compound, C17H17N2O+·BF4, the central imidazolium ring makes dihedral angles of 74.58 (9) and 40.10 (6)° with the phenyl and 2-methoxy­phenyl rings, respectively. In the crystal, a strong ππ inter­action is observed between the imidazolium and 2-methoxy­phenyl rings, with a centroid–centroid distance of 3.5115 (15) Å. In addition, C—H⋯F and C—H⋯O hydrogen bonds and C—H⋯π inter­actions involving the ­phenyl ring are observed.

Related literature

For the synthesis, see: Liu et al.. (2003[Liu, J. P., Chen, J. B., Zhao, J. F., Zhao, Y. H., li, L. & Zhang, H. B. (2003). Synthesis, pp. 2661-2666.]). For general background to N-heterocyclic carbenes, see: Arduengo et al. (1991[Arduengo, A. J., Harlow, R. L. & Kline, M. (1991). J. Am. Chem. Soc. 113, 361-363.]). For the biological activity of imidazolium salts, see: Vik et al. (2007[Vik, A., Hedner, E., Charnock, C., Tangen, L. W., Samuelsen, Ø., Larsson, R., Bohlin, L. & Gundersen, L.-L. (2007). Bioorg. Med. Chem. 15, 4016-4037.]); Demberelnyamba et al. (2004[Demberelnyamba, D., Kim, K. S., Choi, S., Park, S. Y., Lee, H., Kim, C. J. & Yoo, I. D. (2004). Bioorg. Med. Chem. 12, 853-857.]); Dallas et al. (2007[Dallas, A., Kuhtz, H., Farrell, A., Quilty, B. & Nolan, K. (2007). Tetrahedron Lett. 48, 1017-1021.]); Ballistreri et al. (2004[Ballistreri, F. P., Barresi, V., Benedetti, P., Caltabiano, G., Fortuna, C. G., Longo, M. L. & Musumarra, G. (2004). Bioorg. Med. Chem. 12, 1689-1695.]).

[Scheme 1]

Experimental

Crystal data
  • C17H17N2O+·BF4

  • Mr = 352.14

  • Orthorhombic, P 21 21 21

  • a = 7.1880 (13) Å

  • b = 15.114 (3) Å

  • c = 15.358 (3) Å

  • V = 1668.4 (5) Å3

  • Z = 4

  • Mo Kα radiation

  • μ = 0.12 mm−1

  • T = 93 K

  • 0.40 × 0.33 × 0.33 mm

Data collection
  • Rigaku SPIDER diffractometer

  • Absorption correction: none

  • 13633 measured reflections

  • 2197 independent reflections

  • 2069 reflections with I > 2σ(I)

  • Rint = 0.032

Refinement
  • R[F2 > 2σ(F2)] = 0.044

  • wR(F2) = 0.116

  • S = 1.00

  • 2197 reflections

  • 227 parameters

  • H-atom parameters constrained

  • Δρmax = 0.85 e Å−3

  • Δρmin = −0.19 e Å−3

Table 1
Hydrogen-bond geometry (Å, °)

D—H⋯A D—H H⋯A DA D—H⋯A
C7—H7B⋯F3i 0.99 2.30 3.268 (3) 167
C8—H8⋯F4i 0.95 2.34 3.220 (3) 154
C9—H9⋯F1 0.95 2.21 3.122 (3) 161
C10—H10⋯F1ii 0.95 2.37 3.236 (3) 150
C10—H10⋯F2ii 0.95 2.38 3.221 (3) 147
C12—H12⋯O1ii 0.95 2.57 3.292 (3) 133
C14—H14⋯F3iii 0.95 2.48 3.274 (3) 140
C13—H13⋯Cg1ii 0.94 2.61 3.460 (3) 149
Symmetry codes: (i) [-x+1, y+{\script{1\over 2}}, -z+{\script{1\over 2}}]; (ii) [x-{\script{1\over 2}}, -y+{\script{1\over 2}}, -z+1]; (iii) [-x+{\script{3\over 2}}, -y, z+{\script{1\over 2}}]. Cg1 is the centroid of the C1–C6 ring.

Data collection: RAPID-AUTO (Rigaku/MSC, 2004[Rigaku/MSC (2004). RAPID-AUTO and CrystalStructure. Rigaku/MSC Inc., The Woodlands, Texas, USA.]); cell refinement: RAPID-AUTO; data reduction: RAPID-AUTO; program(s) used to solve structure: SHELXS97 (Sheldrick, 2008[Sheldrick, G. M. (2008). Acta Cryst. A64, 112-122.]); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008[Sheldrick, G. M. (2008). Acta Cryst. A64, 112-122.]); molecular graphics: SHELXTL (Sheldrick, 2008[Sheldrick, G. M. (2008). Acta Cryst. A64, 112-122.]); software used to prepare material for publication: SHELXL97.

Supporting information


Comment top

Since the synthesis and isolation of the first stable, crystalline N-heterocyclic carbene (NHC) was disclosed by Arduengo et al. (1991) scientists have paid much attention to this field. In recent years, a large number of N-heterocyclic carbene (NHC) precursors have been synthesized 1,3-Disubstituted imidazolium salts are potential precursors for the synthesis of various transition metal NHCs. In addition, a number of biological activities of imidazolium salts have been reported including antimicrobial, antifungal, antitumor activities (Vik et al., 2007; Demberelnyamba et al., 2004; Dallas et al., 2007; Ballistreri et al., 2004). We report here crystal structure of a NHC precursor, the title compound.

Bond lengths and angles in title molecule (Fig. 1) are normal. The imidazolium ring makes dihedral angles of 74.58 (9)° and 40.10 (6)°, respectively, with the phenyl ring and 2-methoxyphenyl ring. The methoxy group is slightly twisted away from the attached ring [C17—O1—C16—C15 = -7.8 (4)°].

In the crystal, there are strong π-π interactions between imidazolium and 2-methoxyphenyl rings, with a Cg2···Cg2ii distance of 3.5115 (15) Å [symmetry code: (ii) x - 1/2, 1/2 - y, 1 - z] where Cg2 and Cg3 are centroids of the imidazolium and methoxyphenyl rings, respectively. In addition, C—H···F and C—H···O hydrogen bonds and C—H···π interactions involving the C1—C6 phenyl ring are observed (Table 1).

Related literature top

For the synthesis, see: Liu et al.. (2003). For general background to N-heterocyclic carbenes, see: Arduengo et al. (1991). For the biological activity of imidazolium salts, see: Vik et al. (2007); Demberelnyamba et al. (2004); Dallas et al. (2007); Ballistreri et al. (2004). Cg1 is the centroid of the C1–C6 ring.

Experimental top

The title compound was prepared according to the reported procedure of Liu et al.. (2003). Colourless single crystals suitable for X-ray diffraction were obtained by recrystallization from dichloromethane and petroleum ether.

Refinement top

H atoms were placed in calculated positions [C—H = 0.95–0.99 Å] and refined using a riding model, with Uiso(H) = 1.2Ueq(C).

Computing details top

Data collection: RAPID-AUTO (Rigaku/MSC, 2004); cell refinement: RAPID-AUTO (Rigaku/MSC, 2004); data reduction: RAPID-AUTO (Rigaku/MSC, 2004); program(s) used to solve structure: SHELXS97 (Sheldrick, 2008); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008); molecular graphics: PLEASE PROVIDE; software used to prepare material for publication: SHELXL97 (Sheldrick, 2008).

Figures top
[Figure 1] Fig. 1. The molecular structure of the title compound, showing 30% probability displacement ellipsoids and the atomic numbering scheme.
1-Benzyl-3-(2-methoxyphenyl)imidazolium tetrafluoroborate top
Crystal data top
C17H17N2O+·BF4F(000) = 728
Mr = 352.14Dx = 1.402 Mg m3
Orthorhombic, P212121Mo Kα radiation, λ = 0.71073 Å
Hall symbol: P 2ac 2abCell parameters from 5660 reflections
a = 7.1880 (13) Åθ = 3.0–27.5°
b = 15.114 (3) ŵ = 0.12 mm1
c = 15.358 (3) ÅT = 93 K
V = 1668.4 (5) Å3Block, colourless
Z = 40.40 × 0.33 × 0.33 mm
Data collection top
Rigaku SPIDER
diffractometer
2069 reflections with I > 2σ(I)
Radiation source: Rotating AnodeRint = 0.032
Graphite monochromatorθmax = 27.5°, θmin = 3.0°
ω scansh = 99
13633 measured reflectionsk = 1919
2197 independent reflectionsl = 1915
Refinement top
Refinement on F2Primary atom site location: structure-invariant direct methods
Least-squares matrix: fullSecondary atom site location: difference Fourier map
R[F2 > 2σ(F2)] = 0.044Hydrogen site location: inferred from neighbouring sites
wR(F2) = 0.116H-atom parameters constrained
S = 1.00 w = 1/[σ2(Fo2) + (0.068P)2 + 0.46P]
where P = (Fo2 + 2Fc2)/3
2197 reflections(Δ/σ)max = 0.001
227 parametersΔρmax = 0.85 e Å3
0 restraintsΔρmin = 0.19 e Å3
Crystal data top
C17H17N2O+·BF4V = 1668.4 (5) Å3
Mr = 352.14Z = 4
Orthorhombic, P212121Mo Kα radiation
a = 7.1880 (13) ŵ = 0.12 mm1
b = 15.114 (3) ÅT = 93 K
c = 15.358 (3) Å0.40 × 0.33 × 0.33 mm
Data collection top
Rigaku SPIDER
diffractometer
2069 reflections with I > 2σ(I)
13633 measured reflectionsRint = 0.032
2197 independent reflections
Refinement top
R[F2 > 2σ(F2)] = 0.0440 restraints
wR(F2) = 0.116H-atom parameters constrained
S = 1.00Δρmax = 0.85 e Å3
2197 reflectionsΔρmin = 0.19 e Å3
227 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
xyzUiso*/Ueq
B10.6858 (5)0.1082 (2)0.2432 (2)0.0349 (7)
F10.7005 (2)0.18357 (10)0.29508 (10)0.0360 (4)
F20.7661 (3)0.03715 (11)0.28690 (12)0.0520 (5)
F30.7771 (3)0.12215 (13)0.16519 (11)0.0601 (6)
F40.4996 (3)0.09039 (13)0.22721 (13)0.0555 (6)
O10.6091 (3)0.27395 (12)0.65713 (11)0.0314 (4)
N10.4482 (3)0.45145 (13)0.48559 (13)0.0226 (4)
N20.4930 (3)0.31030 (12)0.49196 (12)0.0203 (4)
C10.6888 (4)0.63622 (15)0.48138 (17)0.0291 (5)
H10.64860.64020.42260.035*
C20.8534 (5)0.67656 (17)0.5060 (2)0.0390 (7)
H20.92620.70750.46420.047*
C30.9113 (5)0.67162 (19)0.5918 (2)0.0453 (8)
H31.02370.69960.60910.054*
C40.8069 (5)0.6263 (2)0.6522 (2)0.0460 (8)
H40.84710.62320.71110.055*
C50.6423 (5)0.58515 (17)0.62717 (18)0.0359 (6)
H50.57100.55350.66890.043*
C60.5814 (4)0.59003 (16)0.54127 (16)0.0264 (5)
C70.4059 (4)0.54316 (16)0.51345 (18)0.0289 (5)
H7A0.31670.54190.56260.035*
H7B0.34750.57580.46470.035*
C80.5203 (3)0.42622 (15)0.40606 (16)0.0230 (5)
H80.54580.46380.35790.028*
C90.5478 (3)0.33788 (15)0.40976 (15)0.0211 (5)
H90.59560.30150.36460.025*
C100.4336 (3)0.38076 (16)0.53617 (15)0.0227 (5)
H100.38830.38030.59430.027*
C110.4976 (3)0.22050 (15)0.52293 (15)0.0213 (5)
C120.4486 (3)0.15283 (16)0.46744 (16)0.0235 (5)
H120.41160.16570.40940.028*
C130.4533 (3)0.06574 (16)0.49642 (18)0.0288 (5)
H130.42080.01880.45820.035*
C140.5056 (4)0.04793 (17)0.58102 (19)0.0317 (6)
H140.50700.01160.60100.038*
C150.5562 (3)0.11531 (17)0.63726 (18)0.0305 (6)
H150.59180.10190.69530.037*
C160.5549 (3)0.20287 (16)0.60874 (15)0.0246 (5)
C170.6499 (5)0.2592 (2)0.74763 (17)0.0423 (7)
H17A0.53850.23690.77710.051*
H17B0.68850.31510.77460.051*
H17C0.75040.21580.75290.051*
Atomic displacement parameters (Å2) top
U11U22U33U12U13U23
B10.0408 (16)0.0351 (15)0.0287 (15)0.0150 (14)0.0110 (14)0.0110 (13)
F10.0441 (9)0.0332 (8)0.0308 (8)0.0046 (7)0.0012 (7)0.0122 (7)
F20.0711 (13)0.0394 (9)0.0455 (11)0.0217 (9)0.0260 (10)0.0105 (8)
F30.0828 (15)0.0669 (13)0.0306 (10)0.0258 (12)0.0078 (10)0.0132 (9)
F40.0473 (10)0.0555 (11)0.0638 (13)0.0119 (10)0.0236 (10)0.0256 (10)
O10.0325 (10)0.0403 (10)0.0214 (9)0.0103 (8)0.0031 (8)0.0036 (7)
N10.0221 (9)0.0230 (9)0.0228 (10)0.0009 (8)0.0009 (8)0.0030 (8)
N20.0206 (9)0.0208 (9)0.0194 (9)0.0025 (7)0.0009 (8)0.0011 (7)
C10.0393 (13)0.0219 (10)0.0261 (13)0.0020 (11)0.0057 (11)0.0006 (10)
C20.0464 (16)0.0290 (13)0.0415 (16)0.0099 (12)0.0037 (14)0.0027 (11)
C30.0506 (18)0.0347 (14)0.0504 (18)0.0131 (13)0.0161 (15)0.0031 (13)
C40.065 (2)0.0432 (16)0.0298 (15)0.0067 (16)0.0153 (15)0.0046 (13)
C50.0518 (17)0.0313 (12)0.0245 (13)0.0014 (13)0.0000 (13)0.0046 (10)
C60.0333 (13)0.0212 (10)0.0247 (12)0.0035 (10)0.0001 (10)0.0039 (9)
C70.0308 (12)0.0237 (11)0.0321 (14)0.0052 (10)0.0025 (11)0.0077 (10)
C80.0252 (11)0.0238 (10)0.0200 (11)0.0005 (9)0.0021 (10)0.0004 (9)
C90.0220 (11)0.0225 (10)0.0187 (11)0.0002 (9)0.0019 (9)0.0000 (9)
C100.0214 (10)0.0265 (11)0.0202 (11)0.0009 (9)0.0030 (9)0.0009 (9)
C110.0150 (9)0.0244 (10)0.0245 (12)0.0011 (9)0.0010 (9)0.0044 (9)
C120.0181 (10)0.0250 (11)0.0275 (13)0.0007 (9)0.0002 (9)0.0017 (9)
C130.0233 (11)0.0254 (11)0.0377 (15)0.0009 (10)0.0034 (11)0.0012 (10)
C140.0242 (11)0.0274 (11)0.0435 (15)0.0009 (10)0.0027 (12)0.0092 (11)
C150.0218 (11)0.0378 (13)0.0321 (14)0.0019 (10)0.0002 (10)0.0134 (11)
C160.0179 (10)0.0328 (12)0.0230 (12)0.0045 (10)0.0004 (9)0.0038 (9)
C170.0478 (17)0.0537 (17)0.0253 (14)0.0128 (15)0.0092 (13)0.0070 (13)
Geometric parameters (Å, º) top
B1—F31.382 (4)C5—H50.95
B1—F41.388 (4)C6—C71.509 (4)
B1—F21.392 (3)C7—H7A0.99
B1—F11.394 (3)C7—H7B0.99
O1—C161.363 (3)C8—C91.351 (3)
O1—C171.438 (3)C8—H80.95
N1—C101.325 (3)C9—H90.95
N1—C81.381 (3)C10—H100.95
N1—C71.482 (3)C11—C121.377 (3)
N2—C101.333 (3)C11—C161.406 (3)
N2—C91.387 (3)C12—C131.390 (3)
N2—C111.439 (3)C12—H120.95
C1—C21.383 (4)C13—C141.379 (4)
C1—C61.389 (4)C13—H130.95
C1—H10.95C14—C151.384 (4)
C2—C31.385 (4)C14—H140.95
C2—H20.95C15—C161.394 (3)
C3—C41.376 (5)C15—H150.95
C3—H30.95C17—H17A0.98
C4—C51.391 (5)C17—H17B0.98
C4—H40.95C17—H17C0.98
C5—C61.392 (4)
F3—B1—F4109.5 (2)C6—C7—H7B109.6
F3—B1—F2109.8 (3)H7A—C7—H7B108.1
F4—B1—F2109.6 (3)C9—C8—N1106.9 (2)
F3—B1—F1109.6 (3)C9—C8—H8126.5
F4—B1—F1109.4 (2)N1—C8—H8126.5
F2—B1—F1108.9 (2)C8—C9—N2107.1 (2)
C16—O1—C17117.6 (2)C8—C9—H9126.5
C10—N1—C8109.00 (19)N2—C9—H9126.5
C10—N1—C7124.7 (2)N1—C10—N2108.67 (19)
C8—N1—C7126.2 (2)N1—C10—H10125.7
C10—N2—C9108.33 (19)N2—C10—H10125.7
C10—N2—C11126.33 (19)C12—C11—C16121.0 (2)
C9—N2—C11125.33 (19)C12—C11—N2119.4 (2)
C2—C1—C6121.1 (2)C16—C11—N2119.7 (2)
C2—C1—H1119.5C11—C12—C13119.9 (2)
C6—C1—H1119.5C11—C12—H12120.0
C1—C2—C3119.6 (3)C13—C12—H12120.0
C1—C2—H2120.2C14—C13—C12119.6 (2)
C3—C2—H2120.2C14—C13—H13120.2
C4—C3—C2120.3 (3)C12—C13—H13120.2
C4—C3—H3119.8C13—C14—C15121.1 (2)
C2—C3—H3119.8C13—C14—H14119.5
C3—C4—C5120.0 (3)C15—C14—H14119.5
C3—C4—H4120.0C14—C15—C16120.1 (2)
C5—C4—H4120.0C14—C15—H15120.0
C4—C5—C6120.4 (3)C16—C15—H15120.0
C4—C5—H5119.8O1—C16—C15125.1 (2)
C6—C5—H5119.8O1—C16—C11116.4 (2)
C1—C6—C5118.7 (3)C15—C16—C11118.4 (2)
C1—C6—C7120.9 (2)O1—C17—H17A109.5
C5—C6—C7120.4 (2)O1—C17—H17B109.5
N1—C7—C6110.4 (2)H17A—C17—H17B109.5
N1—C7—H7A109.6O1—C17—H17C109.5
C6—C7—H7A109.6H17A—C17—H17C109.5
N1—C7—H7B109.6H17B—C17—H17C109.5
C6—C1—C2—C30.6 (4)C9—N2—C10—N10.1 (3)
C1—C2—C3—C40.5 (5)C11—N2—C10—N1179.0 (2)
C2—C3—C4—C50.1 (5)C10—N2—C11—C12139.7 (2)
C3—C4—C5—C60.5 (5)C9—N2—C11—C1239.2 (3)
C2—C1—C6—C50.2 (4)C10—N2—C11—C1641.3 (3)
C2—C1—C6—C7177.6 (2)C9—N2—C11—C16139.7 (2)
C4—C5—C6—C10.4 (4)C16—C11—C12—C130.8 (3)
C4—C5—C6—C7178.2 (3)N2—C11—C12—C13179.7 (2)
C10—N1—C7—C696.0 (3)C11—C12—C13—C140.6 (4)
C8—N1—C7—C679.3 (3)C12—C13—C14—C151.0 (4)
C1—C6—C7—N189.0 (3)C13—C14—C15—C160.0 (4)
C5—C6—C7—N188.8 (3)C17—O1—C16—C157.8 (4)
C10—N1—C8—C90.4 (3)C17—O1—C16—C11173.7 (2)
C7—N1—C8—C9176.3 (2)C14—C15—C16—O1177.2 (2)
N1—C8—C9—N20.4 (3)C14—C15—C16—C111.4 (4)
C10—N2—C9—C80.2 (3)C12—C11—C16—O1176.9 (2)
C11—N2—C9—C8179.3 (2)N2—C11—C16—O12.0 (3)
C8—N1—C10—N20.3 (3)C12—C11—C16—C151.7 (3)
C7—N1—C10—N2176.3 (2)N2—C11—C16—C15179.4 (2)
Hydrogen-bond geometry (Å, º) top
D—H···AD—HH···AD···AD—H···A
C7—H7B···F3i0.992.303.268 (3)167
C8—H8···F4i0.952.343.220 (3)154
C9—H9···F10.952.213.122 (3)161
C10—H10···F1ii0.952.373.236 (3)150
C10—H10···F2ii0.952.383.221 (3)147
C12—H12···O1ii0.952.573.292 (3)133
C14—H14···F3iii0.952.483.274 (3)140
C13—H13···Cg1ii0.942.613.460 (3)149
Symmetry codes: (i) x+1, y+1/2, z+1/2; (ii) x1/2, y+1/2, z+1; (iii) x+3/2, y, z+1/2.

Experimental details

Crystal data
Chemical formulaC17H17N2O+·BF4
Mr352.14
Crystal system, space groupOrthorhombic, P212121
Temperature (K)93
a, b, c (Å)7.1880 (13), 15.114 (3), 15.358 (3)
V3)1668.4 (5)
Z4
Radiation typeMo Kα
µ (mm1)0.12
Crystal size (mm)0.40 × 0.33 × 0.33
Data collection
DiffractometerRigaku SPIDER
diffractometer
Absorption correction
No. of measured, independent and
observed [I > 2σ(I)] reflections
13633, 2197, 2069
Rint0.032
(sin θ/λ)max1)0.649
Refinement
R[F2 > 2σ(F2)], wR(F2), S 0.044, 0.116, 1.00
No. of reflections2197
No. of parameters227
H-atom treatmentH-atom parameters constrained
Δρmax, Δρmin (e Å3)0.85, 0.19

Computer programs: RAPID-AUTO (Rigaku/MSC, 2004), SHELXS97 (Sheldrick, 2008), SHELXL97 (Sheldrick, 2008), PLEASE PROVIDE.

Hydrogen-bond geometry (Å, º) top
D—H···AD—HH···AD···AD—H···A
C7—H7B···F3i0.992.303.268 (3)167
C8—H8···F4i0.952.343.220 (3)154
C9—H9···F10.952.213.122 (3)161
C10—H10···F1ii0.952.373.236 (3)150
C10—H10···F2ii0.952.383.221 (3)147
C12—H12···O1ii0.952.573.292 (3)133
C14—H14···F3iii0.952.483.274 (3)140
C13—H13···Cg1ii0.942.613.460 (3)149
Symmetry codes: (i) x+1, y+1/2, z+1/2; (ii) x1/2, y+1/2, z+1; (iii) x+3/2, y, z+1/2.
 

Acknowledgements

The authors thank the Fund Projects of Sichuan Educational Department (grant No. 2005 A104).

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