title: 3-Oxocyclo-butane-carboxylic acid: hydrogen bonding in a small-ring γ-keto acid.
abstract: The title ketocarboxylic acid, C(5)H(6)O(3), is the smallest carboxy-cyclanone to have its crystal structure determined. It adopts a chiral conformation, by rotation of its carboxyl O atoms away from the plane of skeletal symmetry that passes through the carboxyl carbon and both atoms of the ketone carbonyl. The four-membered ring is non-planar, with a shallow fold of 14.3 (1)° along a line connecting the two α-carbons of the ketone group. In the crystal, the molecules are linked by centrosymmetric hydrogen-bond pairing of ordered carboxylic acid groups [O⋯O = 2.6392 (12) Å and O-H⋯O = 175.74 (15)°], yielding two different sets of dimers, related by by a 2(1) screw axis in c, in the cell. A C-H⋯O interaction is also present.
authors.affiliation: Carl A. Olson Memorial Laboratories, Department of Chemistry, Rutgers University, Newark, NJ 07102, USA.
authors.forename: Georgia
authors.initials: G
authors.lastname: Efthimiopoulos
authors.forename: Hugh W
authors.initials: HW
authors.lastname: Thompson
authors.forename: Roger A
authors.initials: RA
authors.lastname: Lalancette