organic compounds\(\def\hfill{\hskip 5em}\def\hfil{\hskip 3em}\def\eqno#1{\hfil {#1}}\)

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ISSN: 2056-9890

1-[(6-Chloro­pyridin-3-yl)meth­yl]imidazolidin-2-iminium chloride

aX-ray Crystallography Laboratory, Post-Graduate Department of Physics, University of Jammu, Jammu Tawi 180 006, India, and bDepartment of Chemistry, Shivaji University, Kolhapur 416 004, India
*Correspondence e-mail: rkvk.paper11@gmail.com

(Received 8 December 2011; accepted 12 December 2011; online 17 December 2011)

The title compound, C9H12ClN4+·Cl, is a natural metabolic product of imidacloprid [systematic name: (E)-1-(6-chloro-3-pyridyl­meth­yl)-N-nitro­imidazolidin-2-yl­idene­amine] and was obtained by the reduction of the latter using Fe in HCl. The dihedral angle between the pyridine and imidazole rings is 62.09 (12)°. The crystal structure is stabilized by N—H⋯Cl and C—H⋯Cl inter­actions involving the chloride anion. The pyridine N and the chloride atoms are not involved in inter­molecular inter­actions.

Related literature

For background to the insecticidal applications of imidacloprid, see: Kanne et al. (2005[Kanne, D. B., Dick, R. A., Tomizawa, M. & Casida, J. E. (2005). Chem. Res. Toxicol. 18, 1479-1484.]); Schulz-Jander et al. (2002[Schulz-Jander, D. A., Leimkuehler, W. M. & Casida, J. E. (2002). Chem. Res. Toxicol. 15, 1158-1165.]); Dai et al. (2010[Dai, Y., Ji, W., Chen, T., Zhang, W., Liu, Z., Ge, F. & Yuan, S. (2010). J. Agric. Food Chem. 58, 2419-2425.]); Tanner (2010[Tanner, G. (2010). MSc thesis, Austrian Agency for Health and Food Safety, Vienna.]). For ring conformations, see: Duax & Norton (1975[Duax, W. L. & Norton, D. A. (1975). Atlas of Steroid Structures, Vol. 1. New York: Plenum Press.]). For related structures, see: Kapoor et al. (2011[Kapoor, K., Gupta, V. K., Kant, R., Deshmukh, M. B. & Sripanavar, C. S. (2011). X-ray Struct. Anal. Online, 27, x55-x56.]).

[Scheme 1]

Experimental

Crystal data
  • C9H12ClN4+·Cl

  • Mr = 247.13

  • Triclinic, [P \overline 1]

  • a = 6.4773 (3) Å

  • b = 7.3091 (3) Å

  • c = 12.4758 (4) Å

  • α = 88.996 (3)°

  • β = 77.214 (3)°

  • γ = 79.925 (3)°

  • V = 566.98 (4) Å3

  • Z = 2

  • Mo Kα radiation

  • μ = 0.55 mm−1

  • T = 293 K

  • 0.3 × 0.2 × 0.1 mm

Data collection
  • Oxford Diffraction Xcalibur Sapphire3 diffractometer

  • Absorption correction: multi-scan (CrysAlis RED; Oxford Diffraction, 2010[Oxford Diffraction (2010). CrysAlis RED and CrysAlis PRO. Oxford Diffraction Ltd, Yarnton, England.]) Tmin = 0.742, Tmax = 1.000

  • 14139 measured reflections

  • 2468 independent reflections

  • 2059 reflections with I > 2σ(I)

  • Rint = 0.035

Refinement
  • R[F2 > 2σ(F2)] = 0.041

  • wR(F2) = 0.108

  • S = 1.03

  • 2468 reflections

  • 137 parameters

  • H-atom parameters constrained

  • Δρmax = 0.36 e Å−3

  • Δρmin = −0.34 e Å−3

Table 1
Hydrogen-bond geometry (Å, °)

D—H⋯A D—H H⋯A DA D—H⋯A
N13—H13A⋯Cl2 0.86 2.39 3.227 (2) 166
N13—H13B⋯Cl2i 0.86 2.33 3.177 (2) 169
N11—H11⋯Cl2ii 0.86 2.60 3.182 (2) 126
C7—H7A⋯Cl2iii 0.97 2.69 3.650 (2) 169
C7—H7B⋯Cl2 0.97 2.80 3.722 (2) 158
Symmetry codes: (i) -x+2, -y, -z+1; (ii) x, y-1, z; (iii) x-1, y, z.

Data collection: CrysAlis PRO (Oxford Diffraction, 2010[Oxford Diffraction (2010). CrysAlis RED and CrysAlis PRO. Oxford Diffraction Ltd, Yarnton, England.]); cell refinement: CrysAlis PRO; data reduction: CrysAlis RED (Oxford Diffraction, 2010[Oxford Diffraction (2010). CrysAlis RED and CrysAlis PRO. Oxford Diffraction Ltd, Yarnton, England.]); 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: ORTEP-3 (Farrugia, 1997[Farrugia, L. J. (1997). J. Appl. Cryst. 30, 565.]); software used to prepare material for publication: PLATON (Spek, 2009[Spek, A. L. (2009). Acta Cryst. D65, 148-155.]) and PARST (Nardelli, 1995[Nardelli, M. (1995). J. Appl. Cryst. 28, 659.]).

Supporting information


Comment top

Imidacloprid is one of the largest selling insecticides worldwide (Tanner, 2010). The discovery of imidacloprid has been referred to as a milestone in the past three decades of insecticidal research. Neonicotinoid insecticides act as antagonists on the pest synaptic nicotinic acetylcholine receptor (nAchRs) of the insect central nervous system (Tanner, 2010). The nitroguanidine moiety of imidacloprid is also a common site for metabolism via cleavage to the guanidine and reduction to des-nitro-imidacloprid. These metabolic modifications often result in an enhanced potency for vertebrate nAchRs and toxicity. (Kanne et al., 2005; Schulz-Jander et al., 2002; Dai et al., 2010). The bond lengths and angles observed in (I) are normal and are comparable with related structures (Kapoor et al., 2011). The imidazole ring adopts an envelope conformation with the asymmetric parameter: ΔCs(C10)=3.63 (Duax et al., 1975). The dihedral angle between the C5N pyridine and C3N2 imidazole ring is 62.09 (12)°. The stabilization of crystal packing (Fig.2) is influenced by intermolecular N—H···Cl and C—H···Cl hydrogen bonds involving the chloride anion (Table 1).

Related literature top

For background to the insecticidal applications of imidacloprid, see: Kanne et al. (2005); Schulz-Jander et al. (2002); Dai et al. (2010); Tanner (2010). For ring conformations, see: Duax & Norton (1975). For related structures, see: Kapoor et al. (2011).

Experimental top

Imidacloprid (12.75 g, 0.05 mol) was dissolved in 30 ml alcohol, fine powdered Fe (5.59 g, 0.10 mol) metal in the proportion of 1:2 was added, followed by 40 ml of conc. HCl. The mixture was refluxed for 10 hrs and the solid product was washed and cleaned by normal organic protocols, separated out, dissolved in alcohol and by the process of slow evaporation a yellowish crystalline compound was separated out. IR (KBr) νmax: 3233, 3083, 2923, 1690 cm-1. 1H NMR (300 MHz, CDCl3) δ: 3.55(s, 2 x CH2), 4.62(s, CH2), 7.36(d, J = 8.2 Hz, Py1H), 7.74(dd, J1= 7.5 Hz, J2 = 2.5 Hz, PyH), 8.21(s, NH), 8.32(s, Py1H) ppm. 13C NMR (300 MHz, CDCl3) δ: 159, 150, 149, 139, 130, 124, 100, 47, 45 ppm. LC—MS/MS (m/z): 211, 193, 175, 169, 133, 126, 84.

Refinement top

All H atoms were positioned geometrically and were treated as riding on their parent C/N atoms, with C—H distances of 0.93–0.97 Å; N—H distances of 0.86 Å and with Uiso(H) = 1.2Ueq(C/N).

Computing details top

Data collection: CrysAlis PRO (Oxford Diffraction, 2010); cell refinement: CrysAlis PRO (Oxford Diffraction, 2010); data reduction: CrysAlis RED (Oxford Diffraction, 2010); program(s) used to solve structure: SHELXS97 (Sheldrick, 2008); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008); molecular graphics: ORTEP-3 (Farrugia, 1997); software used to prepare material for publication: PLATON (Spek, 2009) and PARST (Nardelli, 1995).

Figures top
[Figure 1] Fig. 1. ORTEP view of the molecule with the atom-labeling scheme. The thermal ellipsoids are drawn at the 40% probability level. H atoms are shown as small spheres of arbitrary radii.
[Figure 2] Fig. 2. The packing arrangement of molecules viewed along the a axis. The dashed lines show the intermolecular N—H···Cl and C—H···Cl hydrogen bonds.
1-[(6-Chloropyridin-3-yl)methyl]imidazolidin-2-iminium chloride top
Crystal data top
C9H12ClN4+·ClZ = 2
Mr = 247.13F(000) = 256
Triclinic, P1Dx = 1.448 Mg m3
Hall symbol: -P 1Mo Kα radiation, λ = 0.71073 Å
a = 6.4773 (3) ÅCell parameters from 7015 reflections
b = 7.3091 (3) Åθ = 3.9–29.1°
c = 12.4758 (4) ŵ = 0.55 mm1
α = 88.996 (3)°T = 293 K
β = 77.214 (3)°Plate, yellow
γ = 79.925 (3)°0.3 × 0.2 × 0.1 mm
V = 566.98 (4) Å3
Data collection top
Oxford Diffraction Xcalibur Sapphire3
diffractometer
2468 independent reflections
Radiation source: fine-focus sealed tube2059 reflections with I > 2σ(I)
Graphite monochromatorRint = 0.035
Detector resolution: 16.1049 pixels mm-1θmax = 27.0°, θmin = 3.9°
ω scansh = 88
Absorption correction: multi-scan
(CrysAlis RED; Oxford Diffraction, 2010)
k = 99
Tmin = 0.742, Tmax = 1.000l = 1515
14139 measured reflections
Refinement top
Refinement on F2Secondary atom site location: difference Fourier map
Least-squares matrix: fullHydrogen site location: inferred from neighbouring sites
R[F2 > 2σ(F2)] = 0.041H-atom parameters constrained
wR(F2) = 0.108 w = 1/[σ2(Fo2) + (0.0442P)2 + 0.3165P]
where P = (Fo2 + 2Fc2)/3
S = 1.03(Δ/σ)max = 0.001
2468 reflectionsΔρmax = 0.36 e Å3
137 parametersΔρmin = 0.34 e Å3
0 restraintsExtinction correction: SHELXL97 (Sheldrick, 2008), Fc*=kFc[1+0.001xFc2λ3/sin(2θ)]-1/4
Primary atom site location: structure-invariant direct methodsExtinction coefficient: 0.027 (4)
Crystal data top
C9H12ClN4+·Clγ = 79.925 (3)°
Mr = 247.13V = 566.98 (4) Å3
Triclinic, P1Z = 2
a = 6.4773 (3) ÅMo Kα radiation
b = 7.3091 (3) ŵ = 0.55 mm1
c = 12.4758 (4) ÅT = 293 K
α = 88.996 (3)°0.3 × 0.2 × 0.1 mm
β = 77.214 (3)°
Data collection top
Oxford Diffraction Xcalibur Sapphire3
diffractometer
2468 independent reflections
Absorption correction: multi-scan
(CrysAlis RED; Oxford Diffraction, 2010)
2059 reflections with I > 2σ(I)
Tmin = 0.742, Tmax = 1.000Rint = 0.035
14139 measured reflections
Refinement top
R[F2 > 2σ(F2)] = 0.0410 restraints
wR(F2) = 0.108H-atom parameters constrained
S = 1.03Δρmax = 0.36 e Å3
2468 reflectionsΔρmin = 0.34 e Å3
137 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
Cl20.86358 (8)0.30462 (7)0.60008 (4)0.04939 (19)
Cl10.23994 (12)0.35819 (11)1.17486 (5)0.0720 (2)
N10.1057 (3)0.2611 (3)1.00679 (16)0.0649 (6)
C20.1336 (3)0.2148 (4)0.89995 (19)0.0587 (6)
H20.01260.20070.87450.070*
C30.3286 (3)0.1868 (3)0.82568 (15)0.0365 (4)
C40.5059 (3)0.2069 (3)0.86513 (18)0.0500 (5)
H40.64160.18740.81840.060*
C50.4824 (4)0.2558 (4)0.97404 (19)0.0544 (6)
H50.60020.27001.00230.065*
C60.2785 (4)0.2826 (3)1.03902 (16)0.0473 (5)
C70.3440 (3)0.1424 (3)0.70621 (15)0.0380 (4)
H7A0.21130.19870.68600.046*
H7B0.46000.19590.66130.046*
N80.3828 (3)0.0570 (2)0.68359 (13)0.0392 (4)
C90.2100 (4)0.1652 (3)0.7134 (2)0.0510 (5)
H9A0.09270.11890.67790.061*
H9B0.15500.16320.79230.061*
C100.3206 (4)0.3597 (3)0.6710 (2)0.0566 (6)
H10A0.34860.43990.73080.068*
H10B0.23450.41520.63050.068*
N110.5199 (3)0.3268 (2)0.59921 (15)0.0503 (5)
H110.60490.40640.55250.060*
C120.5523 (3)0.1553 (3)0.61621 (15)0.0388 (4)
N130.7288 (3)0.0930 (3)0.57049 (15)0.0512 (5)
H13A0.74070.01940.58350.061*
H13B0.83250.16460.52760.061*
Atomic displacement parameters (Å2) top
U11U22U33U12U13U23
Cl20.0360 (3)0.0522 (3)0.0531 (3)0.0003 (2)0.0009 (2)0.0019 (2)
Cl10.0869 (5)0.0993 (5)0.0355 (3)0.0398 (4)0.0064 (3)0.0068 (3)
N10.0480 (11)0.1002 (17)0.0444 (11)0.0233 (11)0.0042 (8)0.0210 (10)
C20.0351 (11)0.0911 (18)0.0490 (13)0.0136 (11)0.0034 (9)0.0215 (12)
C30.0359 (10)0.0346 (9)0.0362 (10)0.0034 (7)0.0042 (7)0.0012 (7)
C40.0356 (10)0.0674 (14)0.0445 (11)0.0099 (10)0.0025 (9)0.0040 (10)
C50.0448 (12)0.0730 (15)0.0499 (12)0.0173 (11)0.0145 (10)0.0023 (11)
C60.0590 (13)0.0517 (12)0.0330 (10)0.0199 (10)0.0059 (9)0.0001 (8)
C70.0378 (10)0.0366 (10)0.0361 (10)0.0015 (8)0.0045 (8)0.0021 (7)
N80.0363 (8)0.0393 (9)0.0390 (9)0.0055 (7)0.0023 (7)0.0044 (7)
C90.0455 (12)0.0518 (12)0.0554 (13)0.0158 (10)0.0048 (10)0.0007 (10)
C100.0685 (15)0.0456 (12)0.0600 (14)0.0166 (11)0.0184 (12)0.0011 (10)
N110.0540 (11)0.0429 (10)0.0514 (11)0.0018 (8)0.0136 (8)0.0121 (8)
C120.0384 (10)0.0437 (10)0.0326 (9)0.0016 (8)0.0106 (8)0.0033 (8)
N130.0386 (9)0.0571 (11)0.0497 (10)0.0015 (8)0.0034 (8)0.0121 (8)
Geometric parameters (Å, º) top
Cl1—C61.743 (2)N8—C121.328 (2)
N1—C61.305 (3)N8—C91.460 (3)
N1—C21.346 (3)C9—C101.522 (3)
C2—C31.376 (3)C9—H9A0.9700
C2—H20.9300C9—H9B0.9700
C3—C41.377 (3)C10—N111.455 (3)
C3—C71.509 (3)C10—H10A0.9700
C4—C51.380 (3)C10—H10B0.9700
C4—H40.9300N11—C121.334 (3)
C5—C61.372 (3)N11—H110.8600
C5—H50.9300C12—N131.313 (3)
C7—N81.457 (2)N13—H13A0.8600
C7—H7A0.9700N13—H13B0.8600
C7—H7B0.9700
C6—N1—C2115.96 (19)C12—N8—C9110.48 (17)
N1—C2—C3124.6 (2)C7—N8—C9121.21 (16)
N1—C2—H2117.7N8—C9—C10102.83 (18)
C3—C2—H2117.7N8—C9—H9A111.2
C2—C3—C4116.79 (19)C10—C9—H9A111.2
C2—C3—C7121.09 (18)N8—C9—H9B111.2
C4—C3—C7122.09 (17)C10—C9—H9B111.2
C3—C4—C5120.0 (2)H9A—C9—H9B109.1
C3—C4—H4120.0N11—C10—C9102.83 (18)
C5—C4—H4120.0N11—C10—H10A111.2
C6—C5—C4117.4 (2)C9—C10—H10A111.2
C6—C5—H5121.3N11—C10—H10B111.2
C4—C5—H5121.3C9—C10—H10B111.2
N1—C6—C5125.2 (2)H10A—C10—H10B109.1
N1—C6—Cl1115.99 (17)C12—N11—C10110.36 (17)
C5—C6—Cl1118.74 (17)C12—N11—H11124.8
N8—C7—C3112.18 (15)C10—N11—H11124.8
N8—C7—H7A109.2N13—C12—N8125.00 (19)
C3—C7—H7A109.2N13—C12—N11123.74 (18)
N8—C7—H7B109.2N8—C12—N11111.26 (18)
C3—C7—H7B109.2C12—N13—H13A120.0
H7A—C7—H7B107.9C12—N13—H13B120.0
C12—N8—C7126.77 (17)H13A—N13—H13B120.0
C6—N1—C2—C31.1 (4)C3—C7—N8—C12118.6 (2)
N1—C2—C3—C40.5 (4)C3—C7—N8—C976.9 (2)
N1—C2—C3—C7177.6 (2)C12—N8—C9—C1011.1 (2)
C2—C3—C4—C51.0 (3)C7—N8—C9—C10177.87 (18)
C7—C3—C4—C5177.1 (2)N8—C9—C10—N1114.3 (2)
C3—C4—C5—C60.0 (4)C9—C10—N11—C1213.7 (2)
C2—N1—C6—C52.3 (4)C7—N8—C12—N1310.4 (3)
C2—N1—C6—Cl1175.7 (2)C9—N8—C12—N13176.29 (19)
C4—C5—C6—N11.8 (4)C7—N8—C12—N11168.74 (18)
C4—C5—C6—Cl1176.16 (18)C9—N8—C12—N112.9 (2)
C2—C3—C7—N891.8 (2)C10—N11—C12—N13173.4 (2)
C4—C3—C7—N890.2 (2)C10—N11—C12—N87.4 (2)
Hydrogen-bond geometry (Å, º) top
D—H···AD—HH···AD···AD—H···A
N13—H13A···Cl20.862.393.227 (2)166
N13—H13B···Cl2i0.862.333.177 (2)169
N11—H11···Cl2ii0.862.603.182 (2)126
C7—H7A···Cl2iii0.972.693.650 (2)169
C7—H7B···Cl20.972.803.722 (2)158
Symmetry codes: (i) x+2, y, z+1; (ii) x, y1, z; (iii) x1, y, z.

Experimental details

Crystal data
Chemical formulaC9H12ClN4+·Cl
Mr247.13
Crystal system, space groupTriclinic, P1
Temperature (K)293
a, b, c (Å)6.4773 (3), 7.3091 (3), 12.4758 (4)
α, β, γ (°)88.996 (3), 77.214 (3), 79.925 (3)
V3)566.98 (4)
Z2
Radiation typeMo Kα
µ (mm1)0.55
Crystal size (mm)0.3 × 0.2 × 0.1
Data collection
DiffractometerOxford Diffraction Xcalibur Sapphire3
diffractometer
Absorption correctionMulti-scan
(CrysAlis RED; Oxford Diffraction, 2010)
Tmin, Tmax0.742, 1.000
No. of measured, independent and
observed [I > 2σ(I)] reflections
14139, 2468, 2059
Rint0.035
(sin θ/λ)max1)0.639
Refinement
R[F2 > 2σ(F2)], wR(F2), S 0.041, 0.108, 1.03
No. of reflections2468
No. of parameters137
H-atom treatmentH-atom parameters constrained
Δρmax, Δρmin (e Å3)0.36, 0.34

Computer programs: CrysAlis PRO (Oxford Diffraction, 2010), CrysAlis RED (Oxford Diffraction, 2010), SHELXS97 (Sheldrick, 2008), SHELXL97 (Sheldrick, 2008), ORTEP-3 (Farrugia, 1997), PLATON (Spek, 2009) and PARST (Nardelli, 1995).

Hydrogen-bond geometry (Å, º) top
D—H···AD—HH···AD···AD—H···A
N13—H13A···Cl20.862.393.227 (2)166
N13—H13B···Cl2i0.862.333.177 (2)169
N11—H11···Cl2ii0.862.603.182 (2)126
C7—H7A···Cl2iii0.972.693.650 (2)169
C7—H7B···Cl20.972.803.722 (2)158
Symmetry codes: (i) x+2, y, z+1; (ii) x, y1, z; (iii) x1, y, z.
 

Acknowledgements

RK acknowledges the Department of Science & Technology for the single-crystal X-ray diffractometer sanctioned as a National Facility under project No. SR/S2/CMP-47/2003. He also thanks the UGC for research funding under research project F. No. 37–415/2009 (J&K) (SR).

References

First citationDai, Y., Ji, W., Chen, T., Zhang, W., Liu, Z., Ge, F. & Yuan, S. (2010). J. Agric. Food Chem. 58, 2419–2425.  Web of Science CrossRef CAS PubMed Google Scholar
First citationDuax, W. L. & Norton, D. A. (1975). Atlas of Steroid Structures, Vol. 1. New York: Plenum Press.  Google Scholar
First citationFarrugia, L. J. (1997). J. Appl. Cryst. 30, 565.  CrossRef IUCr Journals Google Scholar
First citationKanne, D. B., Dick, R. A., Tomizawa, M. & Casida, J. E. (2005). Chem. Res. Toxicol. 18, 1479–1484.  Web of Science CrossRef PubMed CAS Google Scholar
First citationKapoor, K., Gupta, V. K., Kant, R., Deshmukh, M. B. & Sripanavar, C. S. (2011). X-ray Struct. Anal. Online, 27, x55–x56.  CrossRef Google Scholar
First citationNardelli, M. (1995). J. Appl. Cryst. 28, 659.  CrossRef IUCr Journals Google Scholar
First citationOxford Diffraction (2010). CrysAlis RED and CrysAlis PRO. Oxford Diffraction Ltd, Yarnton, England.  Google Scholar
First citationSchulz-Jander, D. A., Leimkuehler, W. M. & Casida, J. E. (2002). Chem. Res. Toxicol. 15, 1158–1165.  Web of Science PubMed CAS Google Scholar
First citationSheldrick, G. M. (2008). Acta Cryst. A64, 112–122.  Web of Science CrossRef CAS IUCr Journals Google Scholar
First citationSpek, A. L. (2009). Acta Cryst. D65, 148–155.  Web of Science CrossRef CAS IUCr Journals Google Scholar
First citationTanner, G. (2010). MSc thesis, Austrian Agency for Health and Food Safety, Vienna.  Google Scholar

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