(1R,3S)-Camphoric acid as a building block in supramolecular chemistry: adducts with organic polyamines.
(1R,3S)-Camphoric acid [(1R,3S)-1,2,2,-trimethylcyclopentane-1,3-dicarboxylic acid, C(10)H(16)O(4)] forms adducts with a range of amines in which the acid component may be the neutral molecule, the mono-anion (C(10)H(15)O(4))(-) or the di-anion (C(10)H(14)O(4))(2-). The structures generated by the hard hydrogen bonds take the form of chains in the 1:1 adducts (II) and (III) formed with 4,4'-bipyridyl and 1,2-bis(4-pyridyl)ethane. There are single sheets in the hydrated 1:1 adduct (IV) formed with 1,4-diazabicyclo[2.2.2]octane, and pairwise-interwoven sheets in the 2:1 adduct (V) formed with hexamethylenetetramine. Three-dimensional frameworks are present in the salt-like 1:1 adduct (VI) formed with piperazine and in the hydrated 3:1 adduct (VII) formed with N,N'-dimethylpiperazine. This latter adduct contains both neutral C(10)H(16)O(4) and anionic (C(10)H(15)O(4))(-) units. In (II), (III) and (IV), the chain and sheet substructures are linked by C-H...O hydrogen bonds to form three-dimensional frameworks. The monoclinic polymorph of camphoric acid itself (I) has been reinvestigated.
Zakaria
Choudhury M
CM
School of Chemistry, University of St Andrews, St Andrews, Fife KY16 9ST, Scotland, UK.
Ferguson
George
G
Lough
Alan J
AJ
Glidewell
Christopher
C