From Hexaphenylbenzene to 1,2,3,4,5,6-Hexacyclohexylcyclohexane

The
hydrogenation of hexaphenyl­benzene was studied, affording
novel partially hydrogenated hexacyclo­hexylbenzene (HCB) as well as fully hydrogenated 1,2,3,4,5,6-hexacyclohexyl­cyclohexane
(HCC) as an unprecedented “oligocyclohexyl”
molecule. The reaction process was analyzed by mass spectrometry with
atmospheric pressure chemical ionization and high-performance liquid
chromatography. From a crude product mixture, two different crystals
with flake- and block-shapes could be grown and analyzed by X-ray
crystallography, revealing their structures as HCB and HCC. While a geared arrangement of cyclohexyl substitutes
was found in HCB, two isomeric structures were identified
in HCC crystal with chair and twist-boat conformations
of the central cyclohexane.