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Volume 68 
Part 1 
Page o145  
January 2012  

Received 5 December 2011
Accepted 12 December 2011
Online 17 December 2011

Key indicators
Single-crystal X-ray study
T = 293 K
Mean [sigma](C-C) = 0.002 Å
R = 0.037
wR = 0.104
Data-to-parameter ratio = 15.6
Details
Open access

5-Chloro-1H-indole-3-carboxylic acid

aCollege of Chemistry and Chemical Engineering, Southeast University, Nanjing 210096, People's Republic of China
Correspondence e-mail: chmsunbw@seu.edu.cn

In the title compound, C9H6ClNO2, the carboxyl group is twisted from the indole ring system by 9.00 (8)°. In the crystal, inversion dimers linked by pairs of O-H...O hydrogen bonds generate R22(8) loops and N-H...O hydrogen bonds link the dimers into (001) sheets. Aromatic [pi]-[pi] stacking interactions [centroid-centroid distance = 3.7185 (12) A °] are also observed.

Related literature

For background to indole derivatives as pharmaceuticals, see: Kunzer & Wendt (2011[Kunzer, A. R. & Wendt, M. D. (2011). Tetrahedron, 52, 1815-1818.]); Woodward & Bartel (2005[Woodward, A. W. & Bartel, B. (2005). Ann. Bot. (London), 95, 707-735.]).

[Scheme 1]

Experimental

Crystal data
  • C9H6ClNO2

  • Mr = 195.60

  • Orthorhombic, P b c a

  • a = 7.2934 (15) Å

  • b = 13.065 (3) Å

  • c = 17.902 (4) Å

  • V = 1705.9 (6) Å3

  • Z = 8

  • Mo K[alpha] radiation

  • [mu] = 0.41 mm-1

  • T = 293 K

  • 0.30 × 0.20 × 0.15 mm

Data collection
  • Rigaku SCXmini CCD diffractometer

  • Absorption correction: multi-scan (CrystalClear; Rigaku, 2005[Rigaku. (2005). CrystalClear. Rigaku Corporation, Tokyo, Japan.]) Tmin = 0.907, Tmax = 0.941

  • 16050 measured reflections

  • 1919 independent reflections

  • 1590 reflections with I > 2[sigma](I)

  • Rint = 0.050

Refinement
  • R[F2 > 2[sigma](F2)] = 0.037

  • wR(F2) = 0.104

  • S = 1.04

  • 1919 reflections

  • 123 parameters

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

  • [Delta][rho]max = 0.17 e Å-3

  • [Delta][rho]min = -0.23 e Å-3

Table 1
Hydrogen-bond geometry (Å, °)

D-H...A D-H H...A D...A D-H...A
O1-H1...O2i 0.82 1.86 2.6558 (17) 164
N1-H1B...O2ii 0.86 (2) 2.26 (2) 3.005 (2) 144.3 (19)
Symmetry codes: (i) -x, -y+2, -z+1; (ii) [-x+{\script{1\over 2}}, y-{\script{1\over 2}}, z].

Data collection: CrystalClear (Rigaku, 2005[Rigaku. (2005). CrystalClear. Rigaku Corporation, Tokyo, Japan.]); cell refinement: CrystalClear; data reduction: CrystalClear; 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: DIAMOND (Brandenburg & Putz, 2005[Brandenburg, K. & Putz, H. (2005). DIAMOND. Crystal Impact GbR, Bonn, Germany.]); software used to prepare material for publication: SHELXL97.


Supplementary data and figures for this paper are available from the IUCr electronic archives (Reference: HB6559 ).


Acknowledgements

We thank Southeast University for support.

References

Brandenburg, K. & Putz, H. (2005). DIAMOND. Crystal Impact GbR, Bonn, Germany.
Kunzer, A. R. & Wendt, M. D. (2011). Tetrahedron, 52, 1815-1818.  [ChemPort]
Rigaku. (2005). CrystalClear. Rigaku Corporation, Tokyo, Japan.
Sheldrick, G. M. (2008). Acta Cryst. A64, 112-122.  [CrossRef] [details]
Woodward, A. W. & Bartel, B. (2005). Ann. Bot. (London), 95, 707-735.  [ChemPort]


Acta Cryst (2012). E68, o145  [ doi:10.1107/S1600536811053384 ]

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