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.