Hydrogen-bonding and C—H...π interactions in 1,7-bis(4-hydroxy-3-methoxyphenyl)heptane-3,5-dione (tetrahydrocurcumin)

Abstract

The title compound, C21H24O6, is the reduced form of curcumin, and exhibits important cosmoceutical properties. The mol­ecule is non-planar and the benzene rings positioned at the ends of the heptane chain are orthogonally placed, with a dihedral angle of 84.09 (7)° between them. The molecular geometry and H-atom locations reveal that the `heptane-3,5-dione' moiety exists in the keto–enol form, with the hydroxy H atom disordered over two adjacent sites. The packing of the mol­ecules in the lattice is directed by strong O—H⋯O intermolecular hydrogen bonds, which generate two-dimensional sheets. These sheets are linked by C—H⋯O hydrogen bonds and weak C—H⋯π interactions to develop a three-dimensional network.