ABSTRACT
The asymmetric unit of the title compound, C(8)H(12)O(3), consists of a single conformational enanti-omer, which aggregates in the catemeric acid-to-ketone hydrogen-bonding mode [Oâ¯O = 2.682â (4)â Å and O-Hâ¯O = 172â (6)°]. Four hydrogen-bonding chains of translationally related mol-ecules pass through the cell orthogonal to the 4(3) screw axis along c, alternating in the 110 and the 10 direction, with alignment with respect to this axis of + + - -. Successive chains are rotated by 90° around the c axis. One C-Hâ¯O=C close contact, involving the carboxyl group, exists.
ABSTRACT
The title monohydrate, C(7)H(10)O(3).H(2)O, aggregates as a complex hydrogen-bonding network, in which the water molecule accepts a hydrogen bond from the carboxyl group of one molecule and donates hydrogen bonds to ketone and carboxyl C=O functions in two additional molecules, yielding a sheet-like structure of parallel ribbons. The keto acid adopts a chiral conformation through rotation of the carboxyl group by 62.50 (15) degrees relative to the plane defined by its point of attachment and the ketone C and O atoms. Two C-H.O close contacts exist in the structure.
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.
