(2E,5E)-2,5-Bis(4-hy-droxy-3-meth-oxy-benzyl-idene)cyclo-penta-none ethanol monosolvate

Acta Crystallogr Sect E Struct Rep Online. 2013 Mar 13;69(Pt 4):o530. doi: 10.1107/S1600536813005229. Print 2013 Apr 1.

Abstract

In the title structure, C21H20O5·C2H5OH, the curcumine-type mol-ecule has a double E conformation for the two benzyl-idene double bonds [C=C = 1.342 (4) and 1.349 (4) Å] and is nearly planar with respect to the non-H atoms (r.m.s. deviation from planarity = 0.069 Å). The two phenolic OH groups form bifurcated hydrogen bonds with intra-molecular branches to adjacent meth-oxy O atoms and inter-molecular branches to either a neighbouring mol-ecule or an ethanol solvent mol-ecule. The ethanol O atom donates a hydrogen bond to the keto O atom. These hydrogen bonds link the constituents into layers parallel to (101) in the crystal structure.