Acta Cryst. (2004). E60, o1031±o1033 DOI: 10.1107/S1600536804011651 Christophe M. L. Vande Velde et al.  C 9 H 11 NO 5 o1031 organic papers Acta Crystallographica Section E Structure Reports Online ISSN 1600-5368 2,4,5-Trimethoxy-1-nitrobenzene: a structure in the rare space group P4 2 Christophe M. L. Vande Velde, Herman J. Geise and Frank Blockhuys* Structural Chemistry Group, University of Antwerp, Universiteitsplein 1, B-2610 Wilrijk, Belgium Correspondence e-mail: frank.blockhuys@ua.ac.be Key indicators Single-crystal X-ray study T = 293 K Mean (C±C) = 0.003 A Ê R factor = 0.040 wR factor = 0.118 Data-to-parameter ratio = 11.2 For details of how these key indicators were automatically derived from the article, see http://journals.iucr.org/e. # 2004 International Union of Crystallography Printed in Great Britain ± all rights reserved The achiral title compound, C 9 H 11 NO 5 , crystallizes as a chiral structure in space group P4 2 . Short contacts between the nitro group and two methoxy groups on neighbouring molecules can be seen, as can methoxy±methoxy contacts between the other methoxy groups not involved in this interaction. Comment 2,4,5-Trimethoxy-1-nitrobenzene, (I) (Fig. 1), was synthesized as an intermediate in the route to highly substituted PPV oligomers. It is achiral in solution, but crystallizes as a chiral structure (Flack, 2003) in the tetragonal space group P4 2 with four symmetry-equivalent molecules in the unit cell. There is one molecule in the asymmetric unit. The solid-state structure of (I) is quite remarkable since only 30 compounds in the Cambridge Structural Database (CSD, Version 1.6 with April 2004 update; Allen, 2002) crys- tallize in space group P4 2 and, of those, only two are non- organometallic compounds without chiral centres, namely refcodes HYDTML (Liminga & Sùrensen, 1967) and OKAHUD (Eaton et al., 2003). The distances and angles in this molecule conform to the expected values within experimental error. Note that the lengthening of the C4ÐC5 bond and the associated shortening of C3ÐC4 and C5ÐC6 are due to the lone-pair repulsion of the methoxy O atoms. Indeed, all the methoxy groups lie within 5  of the mean plane of the molecule (see Table 1). The Received 4 May 2004 Accepted 12 May 2004 Online 22 May 2004 Figure 1 The molecular structure of (I), showing 50% probability displacement ellipsoids and the atom-numbering scheme.