organic compounds
Open access
Molecules of the title compound, C18H16O6, are almost planar [maximum deviation = 0.096 (4) Å] and reside on crystallographic centres of inversion. They adopt a conformation in which the Cmethyl—O bonds are directed along the molecular short axis [C—C—O—C torsion angles of −175.3 (3) and 178.2 (3)°]. In the crystal, molecules adopt a slipped-parallel arrangement with π–π stacking interactions along the a axis with an interplanar distance of 3.392 (4) Å. Weak C—HO interactions link the molecules into sheets parallel to (10).
organic compounds
Open access
The title compound, C16H12O4, crystallizes with two half-molecules in the asymmetric unit, each of which is completed by a crystallographic inversion center. The two crystallographically independent molecules have almost the same geometry and are almost planar [maximum deviations = 0.018 (3) and 0.049 (3) Å]. They adopt a conformation in which the Cmethyl—O bonds are directed along the molecular short axis [C—C—O—C torsion angles of 179.6 (2) and 178.0 (2)°]. In the crystal, the molecular packing is characterized by a combination of a columnar stacking and a herringbone-like arrangement. The molecules form slipped π-stacks along the b axis, in which there are two kinds of columns differing from each other in their slippage. The interplanar distances between neighboring molecules are 3.493 (3) for one column and 3.451 (2) Å for the other.