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Volume 69 
Part 7 
Page o1167  
July 2013  

Received 25 April 2013
Accepted 23 June 2013
Online 29 June 2013

Key indicators
Single-crystal X-ray study
T = 291 K
Mean [sigma](C-C) = 0.002 Å
R = 0.037
wR = 0.060
Data-to-parameter ratio = 15.1
Details
Open access

(E)-2-Methoxy-9-(2-methoxy-9H-xanthen-9-ylidene)-9H-xanthene

aDepartment of Chemistry, University of Science and Technology of China, Hefei 230026, People's Republic of China
Correspondence e-mail: qhsong@ustc.edu.cn

The title compound, C28H20O4, was synthesized by a bimolecular Zn-HCl reduction in glacial acetic acid using the methoxy-substituted xanthone as a starting material. The crystal structure shows that the 2,2'-methoxybixanthenylidene unit is an E-type conformation anti-folded conformer. The molecule lies on an inversion center. The methoxy group is almost coplanar with the attached benzene ring, with a C-O-C-C torsion angle of 179.38 (14)°.

Related literature

For background to dixanthylidenes, see: Korenstein et al. (1976[Korenstein, R., Muszkat, K. A., Slifkin, M. A. & Fischer, E. (1976). J. Chem. Soc. Perkin Trans. 2, pp. 438-443.]); Agranat & Tapuhi (1979[Agranat, I. & Tapuhi, Y. (1979). J. Am. Chem. Soc. 101, 665-671.]); Mao et al. (2011[Mao, M., Wu, Q.-Q., Ren, M.-G. & Song, Q.-H. (2011). Org. Biomol Chem. 9, 3165-3169.]). For related structures, see: Mills & Nyburg (1963[Mills, J. F. D. & Nyburg, S. C. (1963). J. Chem. Soc. pp. 308-321.]); Shi et al. (2012[Shi, J., Chang, N., Li, C., Mei, J., Deng, C., Luo, X., Liu, Z., Bo, Z., Dong, Y. Q. & Tang, B. Z. (2012). Chem. Commun. 48, 10675-10677.]).

[Scheme 1]

Experimental

Crystal data
  • C28H20O4

  • Mr = 420.28

  • Monoclinic, P 21 /c

  • a = 8.5699 (7) Å

  • b = 7.5200 (6) Å

  • c = 16.6101 (18) Å

  • [beta] = 102.682 (7)°

  • V = 1044.33 (16) Å3

  • Z = 2

  • Mo K[alpha] radiation

  • [mu] = 0.09 mm-1

  • T = 291 K

  • 0.42 × 0.40 × 0.32 mm

Data collection
  • Oxford Diffraction Gemini S Ultra diffractometer

  • Absorption correction: multi-scan (CrysAlis PRO; Oxford Diffraction, 2007)[Oxford Diffraction (2007). CrysAlis PRO. Oxford Diffraction Ltd, Abingdon, England.] Tmin = 0.964, Tmax = 0.972

  • 6419 measured reflections

  • 2205 independent reflections

  • 1264 reflections with I > 2[sigma](I)

  • Rint = 0.029

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

  • wR(F2) = 0.060

  • S = 1.00

  • 2205 reflections

  • 146 parameters

  • H-atom parameters constrained

  • [Delta][rho]max = 0.16 e Å-3

  • [Delta][rho]min = -0.17 e Å-3

Data collection: CrysAlis PRO (Oxford Diffraction, 2007[Oxford Diffraction (2007). CrysAlis PRO. Oxford Diffraction Ltd, Abingdon, 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: ORTEP-3 for Windows (Farrugia, 2012[Farrugia, L. J. (2012). J. Appl. Cryst. 45, 849-854.]); software used to prepare material for publication: SHELXL97.


Supplementary data and figures for this paper are available from the IUCr electronic archives (Reference: ZQ2201 ).


Acknowledgements

This work was supporting by the National Natural Science Foundation of China (grant Nos. 20972149 and 21272224).

References

Agranat, I. & Tapuhi, Y. (1979). J. Am. Chem. Soc. 101, 665-671.  [CrossRef] [ChemPort]
Farrugia, L. J. (2012). J. Appl. Cryst. 45, 849-854.  [Web of Science] [CrossRef] [ChemPort] [IUCr Journals]
Korenstein, R., Muszkat, K. A., Slifkin, M. A. & Fischer, E. (1976). J. Chem. Soc. Perkin Trans. 2, pp. 438-443.
Mao, M., Wu, Q.-Q., Ren, M.-G. & Song, Q.-H. (2011). Org. Biomol Chem. 9, 3165-3169.  [CrossRef] [ChemPort] [PubMed]
Mills, J. F. D. & Nyburg, S. C. (1963). J. Chem. Soc. pp. 308-321.  [CrossRef]
Oxford Diffraction (2007). CrysAlis PRO. Oxford Diffraction Ltd, Abingdon, England.
Sheldrick, G. M. (2008). Acta Cryst. A64, 112-122.  [CrossRef] [ChemPort] [IUCr Journals]
Shi, J., Chang, N., Li, C., Mei, J., Deng, C., Luo, X., Liu, Z., Bo, Z., Dong, Y. Q. & Tang, B. Z. (2012). Chem. Commun. 48, 10675-10677.  [CrossRef] [ChemPort]


Acta Cryst (2013). E69, o1167  [ doi:10.1107/S1600536813017297 ]

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