Comparative study of the two polymorphic forms of p-(1R,3S) 3-thioanisoyl-1,2,2-trimethylcyclopentane carboxylic acid.
The crystal structure of polymorph I of p-(1R,3S)3-thioanisoyl-1,2,2-trimethylcyclopentane carboxylic acid has been determined and is compared with that of polymorph II that was previously described. Polymorph I is very different at the level of the carboxyl group. It does not present disorder and the values found for the C-O bonds correspond exactly to single and double bond lengths. In addition, the carboxyl groups of the two molecules in the cell packing are involved in symmetric hydrogen bonds [2.662(6) A] leading to the formation of a dimer around the twofold axis following x with a shift on z. The different conformations on the carboxylic group between the two polymorphs are in good agreement with the thermodynamic study.
Rambaud
J
J
URA 418 ENSCM, Montpellier, France.
Bouassab
A
A
Pauvert
B
B
Chevallet
P
P
Declercq
J P
JP
Terol
A
A
D001565:Benzoates / Q000737:chemistry*; D018360:Crystallography, X-Ray; D003517:Cyclopentanes / Q000737:chemistry*; D006860:Hydrogen Bonding; D015394:Molecular Structure; D013237:Stereoisomerism; D013816:Thermodynamics
D001565:Benzoates; D003517:Cyclopentanes; C085799:3-thioanisoyl-1,2,2-trimethylcyclopentane-1-carboxylic acid