organic papers o202 Fernandes et al.  C 8 H 12 N + C 10 H 11 O 2  doi:10.1107/S1600536806052093 Acta Cryst. (2007). E63, o202–o204 Acta Crystallographica Section E Structure Reports Online ISSN 1600-5368 Powder study of (R)-1-phenylethylammonium (R)-2-phenylbutyrate form 3 Philippe Fernandes, a Alastair J. Florence, a * Kenneth Shankland, b Panagiotis G. Karamertzanis, c Ashley T. Hulme c and R. Parathy Anandamanoharan d a Strathclyde Institute of Pharmacy and Biomedical Sciences, John Arbuthnott Building, University of Strathclyde, 27 Taylor Street, Glasgow G4 0NR, Scotland, b ISIS Facility, Rutherford Appleton Laboratory, Chilton, Didcot, Oxon OX11 0QX, England, c Christopher Ingold Laboratory, Department of Chemistry, University College London, 20 Gordon Street, London WC1H 0AJ, England, and d Department of Chemical Engineering, University College London, Torrington Place, London WC1E 7JE, England Correspondence e-mail: alastair.florence@strath.ac.uk Key indicators Powder X-ray study T = 298 K Mean (C–C) = 0.003 A ˚ R factor = 0.026 wR factor = 0.031 For details of how these key indicators were automatically derived from the article, see http://journals.iucr.org/e. Received 17 November 2006 Accepted 1 December 2006 # 2007 International Union of Crystallography All rights reserved The crystal structure of a new polymorph of the title compound, C 8 H 12 N + C 10 H 11 O 2  , was solved by simulated annealing from laboratory X-ray powder diffraction data, collected at 295 K. Subsequent Rietveld refinement using data collected to 1.54 A ˚ resolution, yielded an R wp of 0.030. The compound crystallizes with one (R)-1-phenylethylammonium cation and one (R)-2-phenylbutyrate anion in the asymmetric unit. Comment The title compound is known to crystallize in at least two polymorphic forms, form 1 (Brianso, 1978) and form 2 (Fernandes et al. , 2006). A third polymorph, form 3, (I), was produced in situ by heating a polycrystalline sample of form 2 to 393 K. The sample remained stable upon cooling to 295 K and the powder data were collected at this temperature. The compound crystallizes in the monoclinic space group P2 1 with one (R)-1-phenylethylammonium cation and one Figure 1 The asymmetric unit of (I) with the atom-numbering scheme. Displace- ment spheres are shown at the 50% probability level. The dashed line indicates a hydrogen bond.