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

作者：Nallasivam Angannan; Nethaji Munirathinam; Vembu Nagarajan^*; Jaswant Buckle; Sulochana Nagarajan

来源：Acta Crystallographica Section E-Structure Reports Online, 2009, 65(2): O314-U2075.

DOI：10.1107/S1600536809001019

The title molecule, C(21)H(18)O(8), 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) angstrom] 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)degrees], while in the second polymorph the molecules are close to planar. Both crystal structures are stabilized by C-H center dot center dot center dot O.

• 出版日期2009-2