Molecular assembly with a figure-of-eight nanohoop as a strategy for the collection and stabilization of cyclo[18]carbon

The recently synthesized novel figure-of-eight nanohoop with two strained oligoparaphenylenes (OPPs) was theoretically designed to collect and stabilize new allotropic carbon cyclo[18]carbon (C-18) through molecular assembly. The size adaptability and shape complementarity of C-18 to OPP make it possible for them to combine into extraordinary ring-in-ring supramolecules. Thermodynamic analysis of 2C(18)@OPP showed that the host-guest complex should spontaneously form below 404 K. Molecular dynamics (MD) simulations demonstrated that the assembly of C-18 and OPP into host-guest complexes of up to 1 : 2 can occur at ambient temperature. Various real-space function analyses revealed that the nature of the non-covalent interaction between C-18 and OPP is the van der Waals (vdW) attraction characterized by pi-pi stacking. Photoexcitation makes the host-guest complexes less stable in their S-1 state by causing the central linker to flatten.

Automated summary

A novel figure-of-eight nanohoop with two strained oligoparaphenylenes (OPPs) was designed to collect and stabilize new allotropic carbon cyclo[18]carbon (C-18) through molecular assembly. The host-guest complexes of C-18 and OPP can spontaneously form at ambient temperature through molecular dynamics simulations. The non-covalent interaction between C-18 and OPP is characterized by van der Waals attraction.