title: 2-(3-benzoyl-1-pyridinio)-3,4-dioxocyclobutenolate.
abstract: The title compound, C16H9NO4, also known as the 3-benzoylpyridinium betaine of squaric acid, exhibits a dipolar electronic ground-state structure with a positively charged pyridinium fragment and a negatively charged squarate moiety. In the molecule, the two aromatic rings are twisted by 56.03 (2) degrees relative to one another. The three-dimensional packing of the molecules is stabilized by C-H...O short contacts.
authors.affiliation: Bulgarian Academy of Sciences, Institute of Organic Chemistry, Acad G. Bonchev Street, Building 9, 1113 Sofia, Bulgaria.
authors.forename: Tsonko
authors.initials: T
authors.lastname: Kolev
authors.forename: Denitsa
authors.initials: D
authors.lastname: Yancheva
authors.forename: Boris
authors.initials: B
authors.lastname: Shivachev
authors.forename: Rosica
authors.initials: R
authors.lastname: Petrova
authors.forename: Michael
authors.initials: M
authors.lastname: Spiteller