Received 21 April 2008
The two molecules in the asymmetric unit of the title compound, C13H16O2, form dimers through O-HO hydrogen bonding, resulting in R22(8) rings. Each carboxyl O atom is involved in interamolecular C-HO hydrogen bonds, forming five-membered rings. There exist dissimilar dihedral angles within the two molecules, for example the carboxylate and isopropyl groups make dihedral angles of 59.6 (4) and 71.7 (3)° in the two molecules. There are no intermolecular interactions.
Data collection: APEX2 (Bruker, 2007); cell refinement: APEX2; data reduction: SAINT (Bruker, 2007); program(s) used to solve structure: SHELXS97 (Sheldrick, 2008); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008); molecular graphics: ORTEP-3 for Windows (Farrugia, 1997) and PLATON (Spek, 2003); software used to prepare material for publication: WinGX (Farrugia, 1999) and PLATON.
Supplementary data and figures for this paper are available from the IUCr electronic archives (Reference: JH2064 ).
The authors acknowledge the Higher Education Commission, Islamabad, Pakistan, for funding the purchase of the diffractometer and for financial support to NM for PhD studies under the Indigenous Scholarship Scheme.
Bruker (2005). SADABS. Bruker AXS Inc. Madison, Wisconsin, USA.
Bruker (2007). APEX2 and SAINT. Bruker AXS Inc. Madison, Wisconsin, USA.
Burt, S. (2004). Int. J. Food Microbiol. 94, 223-253.
Farrugia, L. J. (1997). J. Appl. Cryst. 30, 565.
Farrugia, L. J. (1999). J. Appl. Cryst. 32, 837-838.
Hertog, M. G., Kromhout, D., Aravanis, C., Blackburn, H., Buzina, R., Fidanza, F., Giampaoli, S., Jansen, A., Menotti, A. & Nedeljkovic, S. (1995). Arch. Intern. Med. 155, 381-386.
Ma, G. & Hayes, S. E. (2004). J. Labelled Compd Radiopharm. 47, 895-901.
Muhammad, N., Zia-ur-Rehman, , Ali, S. & Meetsma, A. (2007). Acta Cryst. E63, o2174-o2175.
Sheldrick, G. M. (2008). Acta Cryst. A64, 112-122.
Spek, A. L. (2003). J. Appl. Cryst. 36, 7-13.