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ISSN: 2056-9890

2-(2,3,5,6-Tetra­methyl­benzyl­sulfan­yl)pyridine N-oxide

aDepartment of Chemistry, Popes College, Sawyerpuram 628 251, Tamilnadu, India, bDepartment of Physics, Karunya University, Karunya Nagar, Coimbatore 641 114, India, cDepartment of Physics, Popes College, Sawyerpuram 628 251, Tamilnadu, India, and dInstitut für Organische Chemie, Universität Mainz, Duesbergweg 10-14, 55099 Mainz, Germany
*Correspondence e-mail: b_ravidurai@yahoo.com

(Received 5 September 2008; accepted 16 September 2008; online 20 September 2008)

In the title compound, C16H19NOS, the durene ring and the oxopyridyl ring form a dihedral angle of 82.26 (7)°. The crystal structure is stabilized by inter­molecular C—H⋯O hydrogen bonds, weak C—H⋯π inter­actions and ππ inter­actions [centroid–centroid distance of 3.4432 (19) Å], together with intra­molecular S⋯O [2.657 (2) Å] short contacts.

Related literature

For bond-length data, see: Allen et al. (1987[Allen, F. H., Kennard, O., Watson, D. G., Brammer, L., Orpen, A. G. & &Taylor, R. (1987). J. Chem. Soc. Perkin Trans. 2, pp. S1-19.]). For biological activities of N-oxide derivatives see: Bovin et al. (1992[Bovin, D. H. R., Crepon, E. & Zard, S. Z. (1992). Bull. Soc. Chim. Fr. 129, 145-150.]); Katsuyuki et al. (1991[Katsuyuki, N., Carter, B. J., Xu, J. & Hetch, S. M. (1991). J. Am. Chem. Soc. 113, 5099-5100.]). Leonard et al. (1955[Leonard, F., Barklay, F. A., Brown, E. V., Anderson, F. E. & Green, D. M. (1955). Antibiot. Chemother. pp. 261-264.]); Lobana & Bhatia (1989[Lobana, T. S. & Bhatia, P. K. (1989). J. Sci. Ind. Res. 48, 394-401.]); Symons & West (1985[Symons, M. C. R. & West, D.-X. (1985). J. Chem. Soc. Dalton Trans. pp. 379-381.]). For related literature, see: Jebas et al. (2005[Jebas, S. R., Balasubramanian, T., Ravidurai, B. & Kumaresan, S. (2005). Acta Cryst. E61, o2677-o2678.]); Ravindran Durai Nayagam et al. (2008[Ravindran Durai Nayagam, B., Jebas, S. R., Grace, S. & Schollmeyer, D. (2008). Acta Cryst. E64, o409.]).

[Scheme 1]

Experimental

Crystal data
  • C16H19NOS

  • Mr = 273.38

  • Monoclinic, P 21 /c

  • a = 16.601 (6) Å

  • b = 9.1562 (8) Å

  • c = 9.696 (4) Å

  • β = 106.098 (16)°

  • V = 1416.1 (7) Å3

  • Z = 4

  • Cu Kα radiation

  • μ = 1.95 mm−1

  • T = 193 (2) K

  • 0.51 × 0.38 × 0.03 mm

Data collection
  • Enraf–Nonius CAD-4 diffractometer

  • Absorption correction: ψ scan (CORINC; Dräger & Gattow, 1971[Dräger, M. & Gattow, G. (1971). Acta Chem. Scand. 25, 761-762.]) Tmin = 0.480, Tmax = 0.960

  • 2848 measured reflections

  • 2672 independent reflections

  • 2322 reflections with I > 2σ(I)

  • Rint = 0.064

  • 3 standard reflections frequency: 60 min intensity decay: 2%

Refinement
  • R[F2 > 2σ(F2)] = 0.050

  • wR(F2) = 0.144

  • S = 1.05

  • 2672 reflections

  • 176 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
C4—H4⋯O7i 0.95 2.51 3.319 (3) 143
C2—H2⋯Cg2ii 0.95 2.98 3.853 (3) 154
Symmetry codes: (i) [x, -y+{\script{3\over 2}}, z-{\script{1\over 2}}]; (ii) [x, -y-{\script{1\over 2}}, z-{\script{3\over 2}}]. Cg2 is the centroid of the C10–C15 ring.

Data collection: CAD-4 Software (Enraf–Nonius, 1989[Enraf-Nonius (1989). CAD-4 Software. Enraf-Nonius, Delft, The Netherlands.]); cell refinement: CAD-4 Software; data reduction: CORINC (Dräger & Gattow, 1971[Dräger, M. & Gattow, G. (1971). Acta Chem. Scand. 25, 761-762.]); 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: SHELXTL and PLATON (Spek, 2003[Spek, A. L. (2003). J. Appl. Cryst. 36, 7-13.]).

Supporting information


Comment top

N-Oxides and their derivatives show a broad spectrum of biological activity such as antifungal, antimicrobial and antibacterial activities (Lobana & Bhatia, 1989; Symons et al., 1985). These compounds are also found to be involved in DNA strand scission under physiological conditions (Katsuyuki et al., 1991; Bovin et al., 1992). Pyridine N-oxides bearing a sulfur group in position two display significant antimicrobial activity (Leonard et al., 1955). In view of the importance of N-oxides, we have previously reported the crystal structures of N-oxide derivatives (Jebas et al., 2005; Ravindran Durai Nayagam et al., 2008). As an extension of our work on N-oxide derivatives, we report here the crystal structure of the title compound.

The asymmetric unit of (I) consists of one molecule of 2-(2,3,5,6-Tetramethylbenzylsulfanyl)pyridine N-oxide. The bond lengths and angles agree well with the N-oxide derivatives reported earlier (Jebas et al., 2005) The N—O bond lengths are in good agreement with the mean value of 1.304 (15)Å reported in the literature for pyridine N-oxides (Allen et al.,1987).

The pyridine ring and the durene rings are essentially planar with the maximum deviation from planarity being -0.013 (2)Å for atom N6 and -0.011 (2)Å for atom C10 respectively. The dihedral angle formed by the pyridine ring (C1—C5/N6) with the durene ring (C10—C15) is 82.26 (7)°. The atom O7 attached at N6 of the pyridine ring is coplanar, the torsion angle being O7–N6–C5–C4=177.93 (19)°.

The crystal structure is stabilized by intermolecular C—H···O, C–H···π interactions and ππ interactions with the cg1-cg1i distance of 3.4432 (19)Å (Cg1:C1—C5/N6) [symmetry code:(i) 1-X,1-Y,1-Z] together with intramolecular S···O [2.657 (2) Å] short contacts..

Related literature top

For bond-length data, see: Allen et al.(1987).Jebas et al.(2005). For biological activities of N-oxide derivatives see: Bovin et al. (1992); Katsuyuki et al. (1991). Leonard et al. (1955); Lobana & Bhatia (1989); Symons & West (1985). For related literature: Jebas et al.(2005); Ravindran Durai Nayagam et al. (2008).

Experimental top

A mixture of mono(bromomethyl)durene (0.227 g, 1 mmol) and 1-hydroxypyridine-2-thione sodium salt (0.149,1 mmol) in water (30 ml) and methanol (30 ml) was heated at 333 K with stirring for 30 min. The compound formed was filtered off, and dried. The compound was dissolved in chloroform-methanol (1:1 v/v) and allowed to undergo slow evaporation. Fine crystals were obtained after a week

Refinement top

After checking for their presence in the Fourier map, all the hydrogen atoms were placed in calculated positions and allowed to ride on their parent atoms with the C—H = 0.95Å (aromatic); C—H = 0.99 Å(methylene) and C—H = 0.98Å (methyl) with Uiso(H) in the range of 1.2Uequ(C) – 1.5Uequ(C)methyl and methylene.

Computing details top

Data collection: CAD-4 Software (Enraf–Nonius, 1989); cell refinement: CAD-4 Software (Enraf–Nonius, 1989); data reduction: CORINC (Dräger & Gattow, 1971); program(s) used to solve structure: SHELXS97 (Sheldrick, 2008); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008); molecular graphics: SHELXTL (Sheldrick, 2008); software used to prepare material for publication: SHELXTL (Sheldrick, 2008) and PLATON (Spek, 2003).

Figures top
[Figure 1] Fig. 1. The molecular structure of the title compound, showing 50% probability displacement ellipsoids and the atom numbering scheme.
[Figure 2] Fig. 2. The crystal packing of the title compound, viewed down the b axis.
2-(2,3,5,6-Tetramethylbenzylsulfanyl)pyridine N-oxide top
Crystal data top
C16H19NOSF(000) = 584
Mr = 273.38Dx = 1.282 Mg m3
Monoclinic, P21/cCu Kα radiation, λ = 1.54178 Å
Hall symbol: -P 2ybcCell parameters from 25 reflections
a = 16.601 (6) Åθ = 36–45°
b = 9.1562 (8) ŵ = 1.95 mm1
c = 9.696 (4) ÅT = 193 K
β = 106.098 (16)°Plate, colourless
V = 1416.1 (7) Å30.51 × 0.38 × 0.03 mm
Z = 4
Data collection top
Enraf–Nonius CAD-4
diffractometer
2322 reflections with I > 2σ(I)
Radiation source: rotating anodeRint = 0.064
Graphite monochromatorθmax = 69.9°, θmin = 2.8°
ω/2θ scansh = 1920
Absorption correction: ψ scan
(CORINC; Dräger & Gattow, 1971)
k = 110
Tmin = 0.48, Tmax = 0.96l = 110
2848 measured reflections3 standard reflections every 60 min
2672 independent reflections intensity decay: 2%
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)] = 0.050Hydrogen site location: inferred from neighbouring sites
wR(F2) = 0.144H-atom parameters constrained
S = 1.05 w = 1/[σ2(Fo2) + (0.0919P)2 + 0.3984P]
where P = (Fo2 + 2Fc2)/3
2672 reflections(Δ/σ)max < 0.001
176 parametersΔρmax = 0.36 e Å3
0 restraintsΔρmin = 0.34 e Å3
Crystal data top
C16H19NOSV = 1416.1 (7) Å3
Mr = 273.38Z = 4
Monoclinic, P21/cCu Kα radiation
a = 16.601 (6) ŵ = 1.95 mm1
b = 9.1562 (8) ÅT = 193 K
c = 9.696 (4) Å0.51 × 0.38 × 0.03 mm
β = 106.098 (16)°
Data collection top
Enraf–Nonius CAD-4
diffractometer
2322 reflections with I > 2σ(I)
Absorption correction: ψ scan
(CORINC; Dräger & Gattow, 1971)
Rint = 0.064
Tmin = 0.48, Tmax = 0.963 standard reflections every 60 min
2848 measured reflections intensity decay: 2%
2672 independent reflections
Refinement top
R[F2 > 2σ(F2)] = 0.0500 restraints
wR(F2) = 0.144H-atom parameters constrained
S = 1.05Δρmax = 0.36 e Å3
2672 reflectionsΔρmin = 0.34 e Å3
176 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
C10.37023 (12)0.4717 (2)0.5511 (2)0.0350 (4)
C20.34830 (13)0.5167 (2)0.4094 (2)0.0410 (5)
H20.30540.46680.34000.049*
C30.38878 (15)0.6342 (3)0.3689 (3)0.0482 (6)
H30.37450.66470.27150.058*
C40.45024 (14)0.7067 (2)0.4716 (3)0.0468 (5)
H40.47750.78920.44560.056*
C50.47167 (14)0.6594 (2)0.6111 (3)0.0445 (5)
H50.51410.70920.68140.053*
N60.43286 (11)0.54200 (19)0.65006 (19)0.0382 (4)
O70.45448 (11)0.49322 (19)0.78177 (17)0.0531 (4)
S80.32907 (3)0.32912 (5)0.62989 (5)0.0394 (2)
C90.24486 (13)0.2652 (2)0.4783 (2)0.0392 (5)
H9A0.20730.34710.43540.047*
H9B0.26810.22260.40370.047*
C100.19752 (13)0.1513 (2)0.5361 (2)0.0351 (4)
C110.13472 (12)0.1944 (2)0.5995 (2)0.0381 (5)
C120.09035 (13)0.0877 (3)0.6508 (2)0.0453 (5)
C130.11026 (15)0.0575 (3)0.6389 (3)0.0516 (6)
H130.07960.12970.67330.062*
C140.17289 (15)0.1027 (2)0.5791 (3)0.0464 (5)
C150.21801 (13)0.0032 (2)0.5273 (2)0.0389 (5)
C160.11488 (16)0.3533 (3)0.6159 (3)0.0528 (6)
H16A0.05810.37480.55590.079*
H16B0.15530.41460.58570.079*
H16C0.11830.37360.71660.079*
C170.02163 (17)0.1289 (4)0.7180 (3)0.0671 (8)
H17A0.00160.04030.74880.101*
H17B0.02280.18120.64750.101*
H17C0.04470.19200.80130.101*
C180.1893 (2)0.2643 (3)0.5698 (4)0.0711 (8)
H18A0.18250.29130.46940.107*
H18B0.14940.31970.60720.107*
H18C0.24660.28660.62670.107*
C190.28812 (17)0.0409 (3)0.4648 (3)0.0552 (6)
H19A0.29690.14670.47500.083*
H19B0.33970.00990.51580.083*
H19C0.27330.01470.36280.083*
Atomic displacement parameters (Å2) top
U11U22U33U12U13U23
C10.0376 (10)0.0298 (9)0.0427 (11)0.0045 (8)0.0200 (8)0.0011 (8)
C20.0424 (11)0.0396 (11)0.0453 (12)0.0042 (9)0.0192 (9)0.0034 (9)
C30.0505 (12)0.0450 (12)0.0568 (14)0.0085 (10)0.0277 (11)0.0131 (11)
C40.0454 (12)0.0355 (11)0.0695 (15)0.0044 (9)0.0327 (11)0.0055 (11)
C50.0434 (11)0.0348 (11)0.0628 (14)0.0024 (8)0.0272 (11)0.0073 (10)
N60.0417 (9)0.0343 (9)0.0433 (9)0.0019 (7)0.0198 (8)0.0047 (7)
O70.0648 (10)0.0532 (10)0.0401 (9)0.0085 (8)0.0127 (8)0.0019 (7)
S80.0464 (3)0.0368 (3)0.0370 (3)0.0043 (2)0.0148 (2)0.00324 (19)
C90.0447 (11)0.0371 (10)0.0373 (11)0.0016 (9)0.0136 (9)0.0028 (8)
C100.0381 (10)0.0317 (10)0.0369 (10)0.0011 (8)0.0129 (8)0.0012 (8)
C110.0357 (10)0.0398 (11)0.0387 (11)0.0043 (8)0.0102 (8)0.0032 (9)
C120.0383 (11)0.0557 (13)0.0437 (12)0.0067 (10)0.0143 (9)0.0040 (10)
C130.0505 (13)0.0501 (13)0.0531 (14)0.0177 (10)0.0128 (11)0.0048 (11)
C140.0513 (13)0.0323 (11)0.0504 (13)0.0048 (9)0.0054 (10)0.0021 (9)
C150.0419 (10)0.0345 (10)0.0397 (11)0.0052 (8)0.0104 (9)0.0011 (8)
C160.0548 (13)0.0453 (13)0.0585 (15)0.0141 (11)0.0160 (12)0.0079 (11)
C170.0470 (13)0.101 (2)0.0612 (16)0.0133 (14)0.0274 (12)0.0137 (16)
C180.084 (2)0.0320 (12)0.087 (2)0.0009 (12)0.0070 (17)0.0041 (13)
C190.0612 (14)0.0486 (13)0.0611 (15)0.0143 (11)0.0256 (12)0.0044 (12)
Geometric parameters (Å, º) top
C1—N61.365 (3)C12—C131.383 (4)
C1—C21.382 (3)C12—C171.510 (3)
C1—S81.745 (2)C13—C141.387 (4)
C2—C31.382 (3)C13—H130.9500
C2—H20.9500C14—C151.401 (3)
C3—C41.382 (4)C14—C181.511 (3)
C3—H30.9500C15—C191.509 (3)
C4—C51.370 (3)C16—H16A0.9800
C4—H40.9500C16—H16B0.9800
C5—N61.360 (3)C16—H16C0.9800
C5—H50.9500C17—H17A0.9800
N6—O71.306 (2)C17—H17B0.9800
S8—C91.821 (2)C17—H17C0.9800
C9—C101.505 (3)C18—H18A0.9800
C9—H9A0.9900C18—H18B0.9800
C9—H9B0.9900C18—H18C0.9800
C10—C111.406 (3)C19—H19A0.9800
C10—C151.406 (3)C19—H19B0.9800
C11—C121.395 (3)C19—H19C0.9800
C11—C161.510 (3)
N6—C1—C2119.84 (19)C12—C13—C14123.1 (2)
N6—C1—S8111.06 (15)C12—C13—H13118.4
C2—C1—S8129.10 (17)C14—C13—H13118.4
C3—C2—C1120.0 (2)C13—C14—C15118.7 (2)
C3—C2—H2120.0C13—C14—C18119.1 (2)
C1—C2—H2120.0C15—C14—C18122.2 (2)
C2—C3—C4119.3 (2)C14—C15—C10118.9 (2)
C2—C3—H3120.4C14—C15—C19120.5 (2)
C4—C3—H3120.4C10—C15—C19120.6 (2)
C5—C4—C3119.8 (2)C11—C16—H16A109.5
C5—C4—H4120.1C11—C16—H16B109.5
C3—C4—H4120.1H16A—C16—H16B109.5
N6—C5—C4120.7 (2)C11—C16—H16C109.5
N6—C5—H5119.6H16A—C16—H16C109.5
C4—C5—H5119.6H16B—C16—H16C109.5
O7—N6—C5121.28 (19)C12—C17—H17A109.5
O7—N6—C1118.40 (17)C12—C17—H17B109.5
C5—N6—C1120.32 (19)H17A—C17—H17B109.5
C1—S8—C9101.13 (10)C12—C17—H17C109.5
C10—C9—S8106.60 (14)H17A—C17—H17C109.5
C10—C9—H9A110.4H17B—C17—H17C109.5
S8—C9—H9A110.4C14—C18—H18A109.5
C10—C9—H9B110.4C14—C18—H18B109.5
S8—C9—H9B110.4H18A—C18—H18B109.5
H9A—C9—H9B108.6C14—C18—H18C109.5
C11—C10—C15121.22 (19)H18A—C18—H18C109.5
C11—C10—C9119.71 (19)H18B—C18—H18C109.5
C15—C10—C9119.07 (19)C15—C19—H19A109.5
C12—C11—C10119.2 (2)C15—C19—H19B109.5
C12—C11—C16119.0 (2)H19A—C19—H19B109.5
C10—C11—C16121.7 (2)C15—C19—H19C109.5
C13—C12—C11118.7 (2)H19A—C19—H19C109.5
C13—C12—C17120.2 (2)H19B—C19—H19C109.5
C11—C12—C17121.1 (2)
N6—C1—C2—C31.1 (3)C15—C10—C11—C16177.1 (2)
S8—C1—C2—C3179.56 (16)C9—C10—C11—C161.9 (3)
C1—C2—C3—C40.9 (3)C10—C11—C12—C130.6 (3)
C2—C3—C4—C51.6 (3)C16—C11—C12—C13178.4 (2)
C3—C4—C5—N60.3 (3)C10—C11—C12—C17179.2 (2)
C4—C5—N6—O7177.93 (19)C16—C11—C12—C171.8 (3)
C4—C5—N6—C11.7 (3)C11—C12—C13—C140.5 (4)
C2—C1—N6—O7177.22 (18)C17—C12—C13—C14179.7 (2)
S8—C1—N6—O72.2 (2)C12—C13—C14—C150.4 (4)
C2—C1—N6—C52.5 (3)C12—C13—C14—C18179.5 (2)
S8—C1—N6—C5178.13 (14)C13—C14—C15—C100.8 (3)
N6—C1—S8—C9176.64 (14)C18—C14—C15—C10178.2 (2)
C2—C1—S8—C94.0 (2)C13—C14—C15—C19178.5 (2)
C1—S8—C9—C10173.92 (14)C18—C14—C15—C192.5 (4)
S8—C9—C10—C1183.9 (2)C11—C10—C15—C142.0 (3)
S8—C9—C10—C1595.2 (2)C9—C10—C15—C14178.98 (19)
C15—C10—C11—C121.9 (3)C11—C10—C15—C19177.3 (2)
C9—C10—C11—C12179.06 (19)C9—C10—C15—C191.8 (3)
Hydrogen-bond geometry (Å, º) top
D—H···AD—HH···AD···AD—H···A
C4—H4···O7i0.952.513.319 (3)143
C2—H2···Cg2ii0.952.983.853 (3)154
Symmetry codes: (i) x, y+3/2, z1/2; (ii) x, y1/2, z3/2.

Experimental details

Crystal data
Chemical formulaC16H19NOS
Mr273.38
Crystal system, space groupMonoclinic, P21/c
Temperature (K)193
a, b, c (Å)16.601 (6), 9.1562 (8), 9.696 (4)
β (°) 106.098 (16)
V3)1416.1 (7)
Z4
Radiation typeCu Kα
µ (mm1)1.95
Crystal size (mm)0.51 × 0.38 × 0.03
Data collection
DiffractometerEnraf–Nonius CAD-4
diffractometer
Absorption correctionψ scan
(CORINC; Dräger & Gattow, 1971)
Tmin, Tmax0.48, 0.96
No. of measured, independent and
observed [I > 2σ(I)] reflections
2848, 2672, 2322
Rint0.064
(sin θ/λ)max1)0.609
Refinement
R[F2 > 2σ(F2)], wR(F2), S 0.050, 0.144, 1.05
No. of reflections2672
No. of parameters176
H-atom treatmentH-atom parameters constrained
Δρmax, Δρmin (e Å3)0.36, 0.34

Computer programs: CAD-4 Software (Enraf–Nonius, 1989), CORINC (Dräger & Gattow, 1971), SHELXS97 (Sheldrick, 2008), SHELXL97 (Sheldrick, 2008), SHELXTL (Sheldrick, 2008) and PLATON (Spek, 2003).

Hydrogen-bond geometry (Å, º) top
D—H···AD—HH···AD···AD—H···A
C4—H4···O7i0.952.513.319 (3)143.0
C2—H2···Cg2ii0.952.983.853 (3)154
Symmetry codes: (i) x, y+3/2, z1/2; (ii) x, y1/2, z3/2.
 

Acknowledgements

RDN thanks the University Grants Commission, India, for a Teacher Fellowship.

References

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