title: Crystal structure of 6,6'-dimethyl-2H,2'H-3,4'-bichromene-2,2'-dione.
abstract: In the title compound, C20H14O4, the dihedral angle between the two coumarin ring systems is 52.37 (19)°, showing a gauche arrangement across the C-C bond which links the two units. The carbonyl groups of the two coumarin units adopt an s-trans arrangement. In the crystal, pairs of C-H⋯O hydrogen bonds and π-π inter-actions [centroid-centroid distance = 3.631 (2) Å] connect the mol-ecules into inversion dimers.
authors.affiliation: Department of Chemistry, Karnatak University, Dharwad 580 010, India.
authors.forename: Kiran K
authors.initials: KK
authors.lastname: Pujar
authors.affiliation: Department of Chemistry, Karnatak University, Dharwad 580 010, India.
authors.forename: Manohar V
authors.initials: MV
authors.lastname: Kulkarni
authors.affiliation: Department of Physics, M S Ramaiah Institute of Technology, MSRIT Post, Bangalore 560 054, India.
authors.forename: G N
authors.initials: GN
authors.lastname: Anil Kumar
keywords: bicoumarin; crystal structure; hydrogen bonds; π–π inter­actions