Synthesis, Characterization, and Crystal Structure of [6]Cycloparaphenylene

Strained: [6]Cycloparaphenylene, a molecule with 97 kcal mol−1 of strain energy, was synthesized. The synthetic strategy relied on two sequential oxidative dearomatization/addition sequences and a final reductive aromatization reaction (see scheme). The optoelectronic properties of [6]cycloparaphenylene were measured, and the analysis of the X-ray crystal structure revealed a linear packing geometry reminiscent of a carbon nanotube.