Synthesis of a Möbius carbon nanobelt

Abstract

Technologies for the creation of topological carbon nanostructures have greatly advanced synthetic organic chemistry and materials science. Although simple molecular nanocarbons with a belt topology have been constructed, analogous carbon nanobelts with a twist—more specifically, Möbius carbon nanobelts (MCNBs)—have not yet been synthesized owing to their high intrinsic strain. Here we report the synthesis, isolation and characterization of a MCNB. Calculations of strain energies suggest that large MCNBs are synthetically accessible. Designing a macrocyclic precursor with an odd number of repeat units led to a successful synthetic route via Z-selective Wittig reactions and nickel-mediated intramolecular homocoupling reactions, which yielded (25,25)MCNB over 14 steps. NMR spectroscopy and theoretical calculations reveal that the twist moiety of the Möbius band moves quickly around the MCNB molecule in solution. The topological chirality that originates from the Möbius structure was confirmed experimentally using chiral HPLC separation and circular dichroism spectroscopy.

Density functional theory study of Mobius boron-carbon-nitride as potential CH 4 , H 2 S, NH 3 , COCl 2 and CH 3 OH gas sensor

“…In 2022, Segawa et al . [14] successfully synthesized Mobius carbon nanobelts with a green-blueish fluorescence. Graphene-like hexagonal boron-nitride has become a new potential material for gas sensing among researchers.…”

Molecular Möbius strips: twist for a bright future

“…Very recently, Itami and Segawa et al demonstrated the first successful synthesis of a fully fused and fully conjugated Möbius carbon nanobelt. 22 Considering the key strain problem, DFT calculations were conducted in advance of the experimental operations to evaluate the theoretical feasibility of target Möbius carbon nanobelts. According to the calculation results, (25, 25)MCNB ( 21 ) and (15, 15)MCNB ( 23 ) with 5 and 3 repeat units, respectively, were preferentially selected as the target molecules in view of the fact that an even number of repeat units would lead to only the CNB product.…”

Precise Synthesis of Concentric Ring, Helicoid, and Ladder Metallo-Polymers with Chevron-Shaped Monomers

“…In artificial systems, various bottom-up synthetic strategies have been developed for building up a myriad of synthetic macromolecules. To emulate the complexity and functionality of natural substances, increasing attention has been concentrated on precise synthesis of macrocycles, − helical polymers or foldamers, nanoribbons or ladder polymers, , and so forth., with a rigid backbone for facilitating the design and control of desired configurations. For example, many foldamers with aromatic skeletons are designed with monomers having a “V” convergent shape (Figure S1).…”