Synthesis and Properties of [9]Cyclo-1,4-naphthylene: A π-Extended Carbon Nanoring

The first synthesis of a π-extended carbon nanoring, [9]­cyclo-1,4-naphthylene ([9]­CN), has been achieved. Careful structure–property analyses uncovered a number of unique features of [9]­CN that are quite different from those of [9]­CPP, a simple carbon nanoring.