title: (+/-)-3-Oxocyclohexanecarboxylic and -acetic acids: contrasting hydrogen-bonding patterns in two homologous keto acids.
abstract: The crystal structures for the title compounds reveal fundamentally different hydrogen-bonding patterns. (+/-)-3-Oxocyclohexanecarboxylic acid, C(7)H(10)O(3), displays acid-to-ketone catemers having a glide relationship for successive components of the hydrogen-bonding chains which advance simultaneously by two cells in a and one in c [O...O = 2.683 (3) A and O-H...O = 166]. A pair of intermolecular close contacts exists involving the acid carbonyl group. The asymmetric unit in (+/-)-3-oxocyclohexaneacetic acid, C(8)H(12)O(3), utilizes only one of two available isoenthalpic conformers and its aggregation involves mutual hydrogen bonding by centrosymmetric carboxyl dimerization [O.O = 2.648 (3) A and O-H...O = 171]. Intermolecular close contacts exist for both the ketone and the acid carbonyl group.
authors.affiliation: Carl A. Olson Memorial Laboratories, Department of Chemistry, Rutgers University, Newark NJ 07102, USA.
authors.forename: Alan
authors.initials: A
authors.lastname: Barcon
authors.forename: Andrew P J
authors.initials: AP
authors.lastname: Brunskill
authors.forename: Roger A
authors.initials: RA
authors.lastname: Lalancette
authors.forename: Hugh W
authors.initials: HW
authors.lastname: Thompson