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Acta Crystallographica Section E: Structure Reports Online logoLink to Acta Crystallographica Section E: Structure Reports Online
. 2010 Aug 18;66(Pt 9):o2311. doi: 10.1107/S1600536810031648

3-Phenyl­diazen­yl-1,2-dimethyl-1H-indole

Tuncer Hökelek a,*, Nusret Tuna Biçer b, Zeynel Seferoğlu b, Ertan Şahin c
PMCID: PMC3008000  PMID: 21588660

Abstract

In the title mol­ecule, C16H15N3, the indole ring system is planar within 0.021 (3) Å and the phenyl ring is inclined to this plane by 17.32 (14)°. π–π contacts involving the pyrrole rings of inversion-related indole units [centroid–centroid distance = 3.5187 (17) Å] stabilize the crystal structure.

Related literature

For the use and applications of azo compounds, see: Bach et al. (1996 ▶); Bahatti & Seshadri (2004 ▶); Biswas & Umapathy (2000 ▶); Catino & Farris (1985 ▶); Clark & Hester (1993 ▶); Fadda et al. (1994 ▶); Hunger (2003 ▶); Taniike et al. (1996 ▶); Zollinger (2003 ▶); Willner & Rubin (1996 ▶). For related structures, see: Hökelek et al. (2007a ▶,b ▶); Seferoğlu et al. (2006 ▶, 2007 ▶, 2008 ▶). For standard bond lengths, see: Allen et al. (1987 ▶).graphic file with name e-66-o2311-scheme1.jpg

Experimental

Crystal data

  • C16H15N3

  • M r = 249.31

  • Monoclinic, Inline graphic

  • a = 16.3442 (3) Å

  • b = 10.2713 (2) Å

  • c = 16.5312 (3) Å

  • β = 104.264 (3)°

  • V = 2689.64 (9) Å3

  • Z = 8

  • Mo Kα radiation

  • μ = 0.08 mm−1

  • T = 294 K

  • 0.35 × 0.28 × 0.18 mm

Data collection

  • Rigaku R-AXIS RAPID-S diffractometer

  • 27159 measured reflections

  • 2762 independent reflections

  • 1503 reflections with I > 2σ(I)

  • R int = 0.103

Refinement

  • R[F 2 > 2σ(F 2)] = 0.066

  • wR(F 2) = 0.198

  • S = 1.04

  • 2762 reflections

  • 221 parameters

  • H atoms treated by a mixture of independent and constrained refinement

  • Δρmax = 0.11 e Å−3

  • Δρmin = −0.18 e Å−3

Data collection: CrystalClear (Rigaku/MSC, 2005 ▶); cell refinement: CrystalClear; data reduction: CrystalClear; program(s) used to solve structure: SHELXS97 (Sheldrick, 2008 ▶); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008 ▶); molecular graphics: ORTEP-3 for Windows (Farrugia, 1997 ▶); software used to prepare material for publication: WinGX publication routines (Farrugia, 1999 ▶) and PLATON (Spek, 2009 ▶).

Supplementary Material

Crystal structure: contains datablocks I, global. DOI: 10.1107/S1600536810031648/su2202sup1.cif

e-66-o2311-sup1.cif (17.4KB, cif)

Structure factors: contains datablocks I. DOI: 10.1107/S1600536810031648/su2202Isup2.hkl

e-66-o2311-Isup2.hkl (132.9KB, hkl)

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

Acknowledgments

The authors are indebted to the Department of Chemistry, Atatürk University, Erzurum, Turkey, for the use of X-ray diffractometer purchased under grant No. 2003/219 of the University Research Fund.

supplementary crystallographic information

Comment

Azo compounds are very important in the field of dyes, pigments and advanced materials (Hunger, 2003). It has been known for many years that the azo compounds are the most widely used class of dyes, due to their versatile applications in various fields such as the dyeing of textile fibers, the coloring of different materials, colored plastics and polymers, biological-medical studies and advanced applications in organic syntheses (Catino & Farris, 1985; Zollinger, 2003; Bahatti & Seshadri, 2004; Taniike et al., 1996; Fadda et al., 1994). They are also used in the fields of nonlinear optics and optical data storage (Taniike et al., 1996; Bach et al., 1996; Clark & Hester, 1993). Their optical properties depend on not only the spectroscopic properties of the molecules but also their crystallographic arrangements (Biswas & Umapathy, 2000; Willner & Rubin, 1996). Previously, the syntheses, crystal structures, spectroscopic and tautomeric properties of novel azo indole dyes have been reported in solution and solid state (Hökelek et al., 2007a,b; Seferoğlu et al., 2008; Seferoğlu et al., 2007; Seferoğlu et al., 2006). We report herein on the synthesis and crystal structure of the title compound.

The molecular structure of the title molecule is shown in Fig. 1. The bond lengths (Allen et al., 1987) and angles are in normal ranges. The indole ring system is planar to within 0.022 (3) Å, with a dihedral angle of 1.22 (15)° between rings A (N1/C1-C3/C8) and B (C3-C8). The orientation of the phenyl ring C (C11-C16) with respect to the indole ring system may be described by the dihedral angle of 17.32 (14)°. Atoms C9, C10, N2 and N3 are displaced by 0.006 (3), -0.107 (4), 0.003 (2) and 0.050 (2) Å, respectively, from the plane of the indole ring system, hence are almost coplanar.

In the crystal there are π···π contacts involving A rings, of the indole group, related by an inversion center, which stabilize the crystal packing: Cg1—Cg1i distance is 3.519 (2) Å [symmetry code: (i) -x, -y, -z, where Cg1 is the centroid of the pyrrole ring A (N1/C1-C3/C8)].

Experimental

For the preparation of the title compound, aniline (190 mg, 2 mmol) was dissolved in HCl (1.5 ml) and water (4.0 ml). The solution was cooled in an ice-salt bath and a cold solution of NaNO2 (150 mg, 2 mmol) in water (3.0 ml) was added dropwise with stirring. The resulting diazonium salt was cooled in an ice-salt bath and then added dropwise with stirring to 1,2-dimethylindole (300 mg, 2 mmol) in an acetic acid/propionic acid mixture (2:1, 8.0 ml). The solution was stirred at 273-278 K for 1 h and the pH of the reaction mixture was maintained at 4-6 by the simultaneous addition of a sodium hydroxide solution (40-50 ml). The mixture was stirred for a further 1 h. The resulting solid was filtered, washed with cold water and crystallized from ethanol (yield; 440 mg, 92%, m.p. 398 K).

Refinement

The C9 methyl H-atoms were included in calculated positions and treated as riding atoms: C—H = 0.96 Å, with Uiso(H) = 1.5Ueq(C). The remaining H-atoms were located in a difference Fourier map and were refined freely.

Figures

Fig. 1.

Fig. 1.

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The molecular structure of the title molecule with the atom-numbering scheme. Displacement ellipsoids are drawn at the 50% probability level.

Crystal data

C16H15N3 F(000) = 1056
Mr = 249.31 Dx = 1.231 Mg m−3
Monoclinic, C2/c Mo Kα radiation, λ = 0.71073 Å
Hall symbol: -C 2yc Cell parameters from 3396 reflections
a = 16.3442 (3) Å θ = 2.4–26.4°
b = 10.2713 (2) Å µ = 0.08 mm−1
c = 16.5312 (3) Å T = 294 K
β = 104.264 (3)° Block, orange
V = 2689.64 (9) Å3 0.35 × 0.28 × 0.18 mm
Z = 8
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Data collection

Rigaku R-AXIS RAPID-S diffractometer 1503 reflections with I > 2σ(I)
Radiation source: fine-focus sealed tube Rint = 0.103
graphite θmax = 26.4°, θmin = 2.4°
ω scans h = −20→20
27159 measured reflections k = −12→12
2762 independent reflections l = −20→18
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Refinement

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)] = 0.066 Hydrogen site location: inferred from neighbouring sites
wR(F2) = 0.198 H atoms treated by a mixture of independent and constrained refinement
S = 1.04 w = 1/[σ2(Fo2) + (0.0864P)2 + 0.4512P] where P = (Fo2 + 2Fc2)/3
2762 reflections (Δ/σ)max < 0.001
221 parameters Δρmax = 0.11 e Å−3
0 restraints Δρmin = −0.18 e Å−3
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Special details

Geometry. All esds (except the esd in the dihedral angle between two l.s. planes) are estimated using the full covariance matrix. The cell esds are taken into account individually in the estimation of esds in distances, angles and torsion angles; correlations between esds in cell parameters are only used when they are defined by crystal symmetry. An approximate (isotropic) treatment of cell esds is used for estimating esds 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 > 2sigma(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.
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Fractional atomic coordinates and isotropic or equivalent isotropic displacement parameters (Å2)

x y z Uiso*/Ueq
N1 0.08081 (14) 0.0254 (2) 0.10187 (13) 0.0815 (7)
N2 0.14870 (13) 0.1760 (2) −0.06346 (13) 0.0776 (6)
N3 0.12083 (14) 0.2792 (2) −0.10430 (14) 0.0809 (6)
C1 0.13054 (17) 0.0347 (3) 0.04696 (16) 0.0788 (7)
C2 0.10816 (16) 0.1455 (3) −0.00174 (16) 0.0735 (7)
C3 0.04189 (16) 0.2101 (2) 0.02639 (15) 0.0740 (7)
C4 −0.00515 (18) 0.3236 (3) 0.00533 (18) 0.0830 (8)
H4 0.0013 (16) 0.382 (3) −0.0413 (16) 0.091 (8)*
C5 −0.06401 (19) 0.3556 (3) 0.0491 (2) 0.0941 (9)
H5 −0.0962 (17) 0.443 (3) 0.0354 (16) 0.098 (8)*
C6 −0.0776 (2) 0.2777 (3) 0.1129 (2) 0.1000 (10)
H6 −0.1200 (19) 0.301 (3) 0.1470 (17) 0.105 (9)*
C7 −0.03322 (19) 0.1639 (3) 0.13422 (18) 0.0891 (9)
H7 −0.0458 (17) 0.109 (3) 0.1772 (16) 0.096 (9)*
C8 0.02687 (17) 0.1317 (3) 0.09164 (15) 0.0765 (7)
C9 0.0837 (2) −0.0775 (3) 0.16314 (18) 0.1000 (10)
H9A 0.0273 −0.1057 0.1615 0.150*
H9B 0.1099 −0.0451 0.2178 0.150*
H9C 0.1157 −0.1496 0.1504 0.150*
C10 0.1983 (2) −0.0607 (4) 0.0456 (3) 0.1006 (10)
H101 0.177 (2) −0.153 (4) 0.032 (2) 0.139 (13)*
H102 0.239 (2) −0.063 (3) 0.097 (2) 0.118 (12)*
H103 0.232 (2) −0.032 (3) 0.004 (2) 0.122 (12)*
C11 0.16377 (17) 0.3083 (3) −0.16766 (16) 0.0773 (7)
C12 0.24027 (19) 0.2553 (3) −0.17310 (19) 0.0845 (8)
H12 0.2668 (19) 0.184 (3) −0.1278 (18) 0.112 (10)*
C13 0.2756 (2) 0.2934 (4) −0.2364 (2) 0.1010 (10)
H13 0.326 (2) 0.255 (3) −0.2414 (18) 0.099 (9)*
C14 0.2366 (3) 0.3836 (4) −0.2952 (2) 0.1079 (11)
H14 0.265 (3) 0.408 (4) −0.341 (2) 0.158 (14)*
C15 0.1604 (3) 0.4367 (4) −0.2903 (2) 0.1051 (10)
H15 0.1309 (17) 0.507 (3) −0.3271 (18) 0.096 (9)*
C16 0.1245 (2) 0.4012 (3) −0.2262 (2) 0.0936 (9)
H16 0.0750 (19) 0.438 (3) −0.2170 (18) 0.102 (10)*
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Atomic displacement parameters (Å2)

U11 U22 U33 U12 U13 U23
N1 0.0829 (15) 0.0828 (15) 0.0780 (14) 0.0006 (12) 0.0181 (12) 0.0063 (11)
N2 0.0683 (13) 0.0804 (15) 0.0873 (14) −0.0050 (11) 0.0252 (11) −0.0059 (12)
N3 0.0752 (14) 0.0862 (15) 0.0865 (15) −0.0040 (12) 0.0302 (12) 0.0007 (12)
C1 0.0758 (17) 0.0795 (17) 0.0772 (17) −0.0019 (14) 0.0116 (14) −0.0068 (14)
C2 0.0680 (15) 0.0758 (16) 0.0790 (16) −0.0035 (13) 0.0222 (13) −0.0027 (13)
C3 0.0739 (16) 0.0765 (17) 0.0744 (16) −0.0045 (13) 0.0233 (13) 0.0015 (13)
C4 0.0842 (18) 0.0767 (18) 0.094 (2) 0.0042 (15) 0.0336 (15) 0.0079 (15)
C5 0.090 (2) 0.086 (2) 0.117 (2) 0.0084 (16) 0.0458 (18) 0.0033 (18)
C6 0.101 (2) 0.103 (2) 0.110 (2) 0.0037 (19) 0.051 (2) 0.0061 (19)
C7 0.091 (2) 0.105 (2) 0.0790 (18) −0.0056 (18) 0.0354 (15) 0.0061 (16)
C8 0.0760 (16) 0.0780 (17) 0.0737 (16) −0.0014 (14) 0.0150 (13) 0.0014 (13)
C9 0.115 (2) 0.092 (2) 0.0880 (19) −0.0002 (17) 0.0153 (17) 0.0204 (16)
C10 0.093 (2) 0.091 (2) 0.112 (3) 0.0140 (19) 0.016 (2) −0.004 (2)
C11 0.0759 (17) 0.0817 (17) 0.0782 (17) −0.0150 (14) 0.0264 (14) −0.0105 (14)
C12 0.0813 (19) 0.090 (2) 0.089 (2) −0.0125 (16) 0.0355 (16) −0.0158 (16)
C13 0.097 (2) 0.110 (2) 0.110 (3) −0.016 (2) 0.053 (2) −0.023 (2)
C14 0.117 (3) 0.118 (3) 0.100 (3) −0.034 (2) 0.048 (2) −0.013 (2)
C15 0.114 (3) 0.109 (3) 0.092 (2) −0.023 (2) 0.025 (2) 0.006 (2)
C16 0.088 (2) 0.101 (2) 0.095 (2) −0.0115 (18) 0.0307 (18) −0.0004 (18)
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Geometric parameters (Å, °)

N1—C1 1.363 (3) C8—C7 1.382 (4)
N1—C8 1.388 (3) C9—H9A 0.9600
N1—C9 1.457 (3) C9—H9B 0.9600
N2—C2 1.382 (3) C9—H9C 0.9600
N3—N2 1.279 (3) C10—H101 1.02 (4)
N3—C11 1.429 (3) C10—H102 0.93 (3)
C1—C10 1.482 (4) C10—H103 1.03 (3)
C2—C1 1.390 (4) C11—C16 1.397 (4)
C3—C2 1.442 (4) C12—C11 1.387 (4)
C3—C4 1.393 (4) C12—C13 1.371 (4)
C3—C8 1.415 (3) C12—H12 1.06 (3)
C4—C5 1.378 (4) C13—C14 1.380 (5)
C4—H4 1.00 (3) C13—H13 0.93 (3)
C5—H5 1.04 (3) C14—C15 1.381 (5)
C6—C5 1.384 (4) C14—H14 1.01 (4)
C6—H6 1.02 (3) C15—H15 0.99 (3)
C7—C6 1.375 (4) C16—C15 1.381 (4)
C7—H7 0.96 (3) C16—H16 0.94 (3)
C1—N1—C8 109.2 (2) N1—C9—H9B 109.5
C1—N1—C9 126.3 (2) N1—C9—H9C 109.5
C8—N1—C9 124.5 (2) H9A—C9—H9B 109.5
N3—N2—C2 113.8 (2) H9A—C9—H9C 109.5
N2—N3—C11 112.7 (2) H9B—C9—H9C 109.5
N1—C1—C2 109.2 (2) C1—C10—H102 112 (2)
N1—C1—C10 122.2 (3) C1—C10—H101 114 (2)
C2—C1—C10 128.6 (3) C1—C10—H103 110.4 (18)
N2—C2—C1 120.5 (2) H102—C10—H101 108 (3)
N2—C2—C3 132.0 (2) H102—C10—H103 104 (3)
C1—C2—C3 107.5 (2) H101—C10—H103 109 (3)
C4—C3—C2 135.8 (2) C12—C11—N3 125.3 (3)
C4—C3—C8 118.6 (2) C12—C11—C16 119.4 (3)
C8—C3—C2 105.6 (2) C16—C11—N3 115.2 (3)
C3—C4—H4 122.5 (15) C11—C12—H12 116.3 (17)
C5—C4—C3 118.8 (3) C13—C12—C11 119.5 (3)
C5—C4—H4 118.7 (15) C13—C12—H12 124.2 (17)
C4—C5—C6 121.7 (3) C12—C13—C14 121.5 (4)
C4—C5—H5 118.3 (15) C12—C13—H13 119.7 (19)
C6—C5—H5 119.9 (15) C14—C13—H13 118.8 (18)
C5—C6—H6 122.8 (16) C13—C14—C15 119.4 (3)
C7—C6—C5 120.9 (3) C13—C14—H14 118 (2)
C7—C6—H6 116.3 (16) C15—C14—H14 122 (2)
C6—C7—C8 117.9 (3) C14—C15—H15 124.3 (17)
C6—C7—H7 119.2 (17) C16—C15—C14 120.0 (4)
C8—C7—H7 122.9 (17) C16—C15—H15 115.4 (17)
N1—C8—C3 108.5 (2) C11—C16—H16 115.3 (18)
C7—C8—N1 129.5 (3) C15—C16—C11 120.2 (4)
C7—C8—C3 122.0 (3) C15—C16—H16 124.5 (18)
N1—C9—H9A 109.5
C8—N1—C1—C2 −1.7 (3) C8—C3—C2—C1 −0.7 (3)
C8—N1—C1—C10 176.5 (3) C2—C3—C4—C5 −178.6 (3)
C9—N1—C1—C2 179.3 (2) C8—C3—C4—C5 0.4 (4)
C9—N1—C1—C10 −2.4 (4) C2—C3—C8—N1 −0.3 (3)
C1—N1—C8—C3 1.2 (3) C2—C3—C8—C7 179.8 (2)
C1—N1—C8—C7 −178.9 (3) C4—C3—C8—N1 −179.6 (2)
C9—N1—C8—C3 −179.8 (2) C4—C3—C8—C7 0.5 (4)
C9—N1—C8—C7 0.0 (4) C3—C4—C5—C6 −0.2 (5)
N3—N2—C2—C1 178.9 (2) C7—C6—C5—C4 −0.9 (5)
N3—N2—C2—C3 −1.8 (4) C8—C7—C6—C5 1.8 (5)
C11—N3—N2—C2 −179.98 (19) N1—C8—C7—C6 178.6 (3)
N2—N3—C11—C12 −15.8 (4) C3—C8—C7—C6 −1.6 (4)
N2—N3—C11—C16 166.1 (2) N3—C11—C16—C15 −179.9 (3)
N2—C2—C1—N1 −179.0 (2) C12—C11—C16—C15 2.0 (4)
N2—C2—C1—C10 2.9 (4) C11—C12—C13—C14 −0.1 (5)
C3—C2—C1—N1 1.5 (3) C13—C12—C11—N3 −178.8 (2)
C3—C2—C1—C10 −176.6 (3) C13—C12—C11—C16 −0.9 (4)
C4—C3—C2—N2 −1.0 (5) C13—C14—C15—C16 1.1 (5)
C4—C3—C2—C1 178.4 (3) C12—C13—C14—C15 0.0 (5)
C8—C3—C2—N2 179.9 (2) C11—C16—C15—C14 −2.1 (5)
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Footnotes

Supplementary data and figures for this paper are available from the IUCr electronic archives (Reference: SU2202).

References

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Associated Data

This section collects any data citations, data availability statements, or supplementary materials included in this article.

Supplementary Materials

Crystal structure: contains datablocks I, global. DOI: 10.1107/S1600536810031648/su2202sup1.cif

e-66-o2311-sup1.cif (17.4KB, cif)

Structure factors: contains datablocks I. DOI: 10.1107/S1600536810031648/su2202Isup2.hkl

e-66-o2311-Isup2.hkl (132.9KB, hkl)

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

Articles from Acta Crystallographica Section E: Structure Reports Online are provided here courtesy of International Union of Crystallography

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