All-cis 1,2,3,4,5,6-hexafluorocyclohexane is a facially polarized cyclohexane

The highest-energy stereoisomer of 1,2,3,4,5,6-hexafluorocyclohexane, in which all of the fluorines are 'up', is prepared in a 12-step protocol. The molecule adopts a classic chair conformation with alternate C-F bonds aligned triaxially, clustering three highly electronegative fluorine atoms in close proximity. This generates a cyclohexane with a high molecular dipole (mu = 6.2 D), unusual in an otherwise aliphatic compound. X- ray analysis indicates that the intramolecular F-ax ... F-ax distances (similar to 2.77 angstrom) are longer than the vicinal F-ax ... F-eq distances (similar to 2.73 angstrom) suggesting a tension stabilizing the chair conformation. In the solid state the molecules pack in an orientation consistent with electrostatic ordering. Our synthesis of this highest-energy isomer demonstrates the properties that accompany the placement of axial fluorines on a cyclohexane and the unusual property of a facially polarized ring in organic chemistry. Derivatives have potential as new motifs for the design of functional organic molecules or for applications in supramolecular chemistry design.