Molecular loops and belts

Recent advances in the theoretical study of molecular loops and belts have revealed new aspects of π systems exhibiting unusual topology. The experimental success/failure toward the synthesis of molecular loops and belts demonstrated that cage structures derived from fullerene frameworks which fix the π systems play a crucial role in stabilizing the otherwise elusive conjugated π systems such as trannulenes and cyclophenacenes. With knowledge of the strategy for the synthesis together with their characteristic properties in hand, it is convincingly expected that more previously unknown loops and belts would be realized soon, resulting in new potentials and applications in novel aromatic compounds.