Möbius basket molecule: structure and properties

Abstract

Expanding the non-knot region of the famous Möbius strip with topological one-sided characteristics, an interesting structure of a Möbius basket molecule with all real frequencies was obtained at the B3LYP/6-31G(d) level for the first time. This structure contains six fused five-membered pyrrole rings contrasting with the isolated pentagon rule for the fullerenes. The twisted handle joints the outer and inner surfaces of the bowl to form a one-sided container molecule. Comparing the Möbius basket to its isomers of a Möbius strip and a normal basket, the framework shape effects on the structure and properties are systematically exhibited. Especially, (1) the basket-making effect increases kinetic stability (the HOMO–LUMO gap increases from 1.116 eV for Möbius strip to 1.608 eV for Möbius basket); (2) from the normal basket to the Möbius basket, the twisting effect obviously increases the static first hyperpolarizability (from 2836 to 3773 au) and IP (from 6.622 to 6.857 eV). It is found that the aza atom, knot, the bowl, and the combination of the knot and bowl units are important regulating factors for the charge transfer (CT) direction in the crucial transitions. This provides the possibility to control the charge transfer direction in crucial transitions by variation of the structures, which is important for the designs of the new optical and photoelectric materials and devices with good performances.