2',4'-Dihydroxy-3-methoxy-alpha,beta-dihydrochalcone and 2',4-dihydroxy-alpha,beta-dihydrochalcone: supramolecular structures formed by O-H...O, C-H...O and stacking interactions.

The crystal structures of 2',4'-dihydroxy-3-methoxy-alpha,beta-dihydrochalcone, C16H16O4, and 2',4-dihydroxy-alpha,beta-dihydrochalcone, C15H14O3, have been determined. In both compounds, the structure consists of two nearly planar six-membered aromatic rings connected by a propanal chain, which is bent in the methoxy compound and almost straight in the other compound. In the crystal structures, the molecular units of both compounds are linked by O-H...O hydrogen bonds to form infinite one-dimensional chains. Hydrogen bonds and C-H...O contacts in the crystal structures were studied by topological analysis of charge density based on Hartree-Fock calculations. Almost all of the investigated C-H...O contacts should be characterized as weak hydrogen bonds.