Crystal Structure of 3,4,5,6-Tetrahydrophthalic Anhydride at 150 K

• Published in: Helvetica chimica acta 2004-06, Vol.87 (6), p.1527-1535
• Main Authors: Fredj, Arij Ben, Bagieu-Beucher, Muriel, Rejeb, Sadok Ben, Lakhdar, Zohra Ben
• Format: Article
• Language: English
• ISSN: 0018-019X; 1522-2675
• DOI: 10.1002/hlca.200490140

The crystal structure of 3,4,5,6‐tetrahydrophthalic anhydride, (=4,5,6,7‐tetrahydroisobenzofuran‐1,3‐dione; 1; C8H8O3) was determined and refined by an analysis of three‐dimensional X‐ray‐diffraction data at 150 K. This bicyclic compound crystallizes in space group Pbca with two symmetry‐independent molecules I and II per asymmetric unit. The cyclohexene ring in both molecules adopts a half‐chair conformation. The obtained conformational descriptions of the six‐membered rings in the crystal phase are consistent with conformational data derived from molecular‐orbital calculations. The structure analysis evidences considerable distorsion of the partially hydrogenated six‐membered ring; the furan ring is flattened in molecule I and slightly deviated from planarity in molecule II. The short intermolecular distances found for CO⋅⋅⋅CO are interpreted as evidence for nonbonded interactions of the dipole–dipole type. The rather long O⋅⋅⋅H distances indicate that the C(sp3)‐H⋅⋅⋅O interactions are weak.