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Volume 69 
Part 5 
Pages o786-o787  
May 2013  

Received 14 April 2013
Accepted 16 April 2013
Online 27 April 2013

Key indicators
Single-crystal X-ray study
T = 200 K
Mean [sigma](C-C) = 0.003 Å
R = 0.044
wR = 0.112
Data-to-parameter ratio = 16.6
Details
Open access

2-[(3,3-Dimethylindolin-2-ylidene)methyl]-4-[(3,3-dimethyl-3H-indol-1-ium-2-yl)methylidene]-3-oxocyclobut-1-en-1-olate chloroform disolvate

aScience and Engineering Faculty, Queensland University of Technology, GPO Box 2434, Brisbane, Queensland 4001, Australia, and bExilica Limited, The Technocentre, Puma Way, Coventry CV1 2TT, England
Correspondence e-mail: g.smith@qut.edu.au

In the title squaraine dye solvate, C26H24N2O2·2CHCl3, the dye molecule is essentially planar, except for the methyl groups, having a maximum deviation over the 26-membered delocalized bond system of 0.060 (2) Å. It possesses crystallographic twofold rotational symmetry with the indole ring systems adopting a syn conformation. The molecular structure features intramolecular N-H...O hydrogen bonds enclosing conjoint S7 ring motifs about one of the dioxocyclobutene O atoms, while the two chloroform solvent molecules are linked to the second O atom through C-H...O hydrogen bonds.

Related literature

For the first report of bis(indolenine)squaraine dyes with alkyl substituents on the N-atom of each of the indolenine rings, see: Sprenger Von & Ziegenbein (1967[Sprenger Von, H.-E. & Ziegenbein, W. (1967). Angew. Chem. 79, 581-582.]). For background to bis(indolenine)squaraine dyes as biomarkers, see: Patsenker et al. (2011[Patsenker, L. D., Tatarets, A. L., Povrozin, Y. A. & Terpetschnig, E. A. (2011). Bioanal. Rev. 3, 115-137.]); Sameiro & Gonçalves (2009[Sameiro, M. & Gonçalves, T. (2009). Chem. Rev. 109, 190-212.]). For the structures of some analogues of the parent dye, see: Kobiyashi et al. (1986[Kobiyashi, Y., Goto, M. & Kurahashi, M. (1986). Bull. Chem. Soc. Jpn, 59, 311-312.]); Natsukawa & Nakazumi (1993[Natsukawa, K. & Nakazumi, H. (1993). Sangyo Gij. Sogo Kenk. Hokuku, 6, 16-21.]); Tong & Peng (1999[Tong, L. & Peng, B.-X. (1999). Dyes Pigments, 43, 73-76.]); Lynch & Byriel (1999[Lynch, D. E. & Byriel, K. A. (1999). Cryst. Eng. 2, 225-239.]); Lynch (2002[Lynch, D. E. (2002). Acta Cryst. E58, o1025-o1027.]); Arunkumar et al. (2007[Arunkumar, E., Sudeep, P. K., Kamat, P. V., Noll, B. C. & Smith, B. D. (2007). New J. Chem. 31, 677-683.]); Matsui et al. (2012[Matsui, M., Fukushima, M., Kubota, Y., Funabiki, K. & Shiro, M. (2012). Tetrahedron, 68, 1931-1935.]); Lynch et al. (2012[Lynch, D. E., Kirkham, V. B., Chowdhury, M. Z. H., Wane, E. S. & Heptinstall, J. (2012). Dyes Pigments, 60, 393-402.]).

[Scheme 1]

Experimental

Crystal data
  • C26H24N2O2·2CHCl3

  • Mr = 635.21

  • Monoclinic, C 2/c

  • a = 20.4270 (11) Å

  • b = 13.5433 (5) Å

  • c = 11.4259 (5) Å

  • [beta] = 109.561 (5)°

  • V = 2978.5 (3) Å3

  • Z = 4

  • Mo K[alpha] radiation

  • [mu] = 0.61 mm-1

  • T = 200 K

  • 0.40 × 0.22 × 0.20 mm

Data collection
  • Oxford Diffraction Gemini-S CCD-detector diffractometer

  • Absorption correction: multi-scan (CrysAlis PRO; Agilent, 2012[Agilent (2012). CrysAlis PRO. Agilent Technologies Ltd, Yarnton, England.]) Tmin = 0.794, Tmax = 0.888

  • 10054 measured reflections

  • 2926 independent reflections

  • 2415 reflections with I > 2[sigma](I)

  • Rint = 0.027

Refinement
  • R[F2 > 2[sigma](F2)] = 0.044

  • wR(F2) = 0.112

  • S = 1.02

  • 2926 reflections

  • 176 parameters

  • H-atom parameters constrained

  • [Delta][rho]max = 0.54 e Å-3

  • [Delta][rho]min = -0.50 e Å-3

Table 1
Hydrogen-bond geometry (Å, °)

D-H...A D-H H...A D...A D-H...A
N1-H1...O2 0.88 1.96 2.7835 (18) 156
C15-H15...O1 0.98 2.13 3.075 (3) 161

Data collection: CrysAlis PRO (Agilent, 2012[Agilent (2012). CrysAlis PRO. Agilent Technologies Ltd, Yarnton, England.]); cell refinement: CrysAlis PRO; data reduction: CrysAlis PRO; 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: PLATON (Spek, 2009[Spek, A. L. (2009). Acta Cryst. D65, 148-155.]); software used to prepare material for publication: PLATON.


Supplementary data and figures for this paper are available from the IUCr electronic archives (Reference: SU2588 ).


Acknowledgements

The authors acknowledge financial support from the Australian Research Council and the Science and Engineering Faculty and the University Library, Queensland University of Technology. John Langley (Southampton University, England) is thanked for the collection of electrospray mass spectroscopy data.

References

Agilent (2012). CrysAlis PRO. Agilent Technologies Ltd, Yarnton, England.
Arunkumar, E., Sudeep, P. K., Kamat, P. V., Noll, B. C. & Smith, B. D. (2007). New J. Chem. 31, 677-683.  [CSD] [CrossRef] [ChemPort] [PubMed]
Kobiyashi, Y., Goto, M. & Kurahashi, M. (1986). Bull. Chem. Soc. Jpn, 59, 311-312.
Lynch, D. E. (2002). Acta Cryst. E58, o1025-o1027.  [CrossRef] [details]
Lynch, D. E. & Byriel, K. A. (1999). Cryst. Eng. 2, 225-239.  [CSD] [CrossRef] [ChemPort]
Lynch, D. E., Kirkham, V. B., Chowdhury, M. Z. H., Wane, E. S. & Heptinstall, J. (2012). Dyes Pigments, 60, 393-402.  [CSD] [CrossRef]
Matsui, M., Fukushima, M., Kubota, Y., Funabiki, K. & Shiro, M. (2012). Tetrahedron, 68, 1931-1935.  [CSD] [CrossRef] [ChemPort]
Natsukawa, K. & Nakazumi, H. (1993). Sangyo Gij. Sogo Kenk. Hokuku, 6, 16-21.  [ChemPort]
Patsenker, L. D., Tatarets, A. L., Povrozin, Y. A. & Terpetschnig, E. A. (2011). Bioanal. Rev. 3, 115-137.  [CrossRef]
Sameiro, M. & Gonçalves, T. (2009). Chem. Rev. 109, 190-212.  [PubMed]
Sheldrick, G. M. (2008). Acta Cryst. A64, 112-122.  [CrossRef] [ChemPort] [details]
Spek, A. L. (2009). Acta Cryst. D65, 148-155.  [ISI] [CrossRef] [ChemPort] [details]
Sprenger Von, H.-E. & Ziegenbein, W. (1967). Angew. Chem. 79, 581-582.
Tong, L. & Peng, B.-X. (1999). Dyes Pigments, 43, 73-76.  [CrossRef]


Acta Cryst (2013). E69, o786-o787   [ doi:10.1107/S1600536813010386 ]

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