Acta Cryst. (2009). E65, o314-o315  [ doi:10.1107/S1600536809001019 ]

Dimethyl 2,2'-[(4-oxo-2-phenyl-4H-chromene-5,7-diyl)dioxy]diacetate: a less densely packed polymorph

A. Nallasivam, M. Nethaji, N. Vembu, B. Jaswant and N. Sulochana

Abstract: The title molecule, C₂₁H₁₈O₈, crystallizes in two crystal polymorphs, see also Nallasivam, Nethaji, Vembu & Jaswant [Acta Cryst. (2009), E65, o312-o313]. The main difference between the two polymorphs is in the conformation of the oxomethylacetate groups with regard to the almost planar [total puckering amplitude 0.047 (2) Å] chromene ring. In the title compound, the best planes of the oxomethylacetate groups through the non-H atoms are almost perpendicular to the chromene ring [making dihedral angles of 89.61 (6) and 80.59 (5)°], while in the second polymorph the molecules are close to planar. Both crystal structures are stabilized by C-HO.

Online 14 January 2009

Copyright © International Union of Crystallography
IUCr Webmaster