title: 2,6-Dimeth-oxy-9,10-anthraquinone.
abstract: The title compound, C(16)H(12)O(4), crystallizes with two half-mol-ecules in the asymmetric unit, each of which is completed by a crystallographic inversion center. The two crystallographically independent mol-ecules 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 C(meth-yl)-O bonds are directed along the mol-ecular short axis [C-C-O-C torsion angles of 179.6 (2) and 178.0 (2)°]. In the crystal, the mol-ecular packing is characterized by a combination of a columnar stacking and a herringbone-like arrangement. The mol-ecules form slipped π-stacks along the b axis, in which there are two kinds of columns differing from each other in their slippage. The inter-planar distances between neighboring mol-ecules are 3.493 (3) for one column and 3.451 (2) Å for the other.
authors.affiliation: Department of Chemistry, Faculty of Science, Shinshu University, 3-1-1 Asahi, Matsumoto, Nagano 390-8621,  Japan.
authors.forename: Akira
authors.initials: A
authors.lastname: Ohta
authors.forename: Kazuki
authors.initials: K
authors.lastname: Hattori
authors.forename: Takashi
authors.initials: T
authors.lastname: Kobayashi
authors.forename: Hiroyoshi
authors.initials: H
authors.lastname: Naito
authors.forename: Takeshi
authors.initials: T
authors.lastname: Kawase
authors.forename: Chitoshi
authors.initials: C
authors.lastname: Kitamura