Möbius Kekulene
Abstract
Encoding prescribed topologies in rigid conjugated frameworks offers a route to tuning electronic properties but is constrained by severe geometric strain. We synthesized and isolated Möbius kekulene, a compact, all-benzenoid double-stranded counterpart of planar kekulene. Its synthesis was enabled by strain-trajectory programming, in which precursor connectivity is designed to control strain accumulation during cyclization. Comparison of two precursors revealed contrasting strain trajectories: MCP1 concentrated the torsional deformation into an inaccessible late-stage closure, whereasMCP2 accommodated deformation progressively, reducing the largest strain increment and affording Möbius kekulene 1. Crystallography confirms a singly twisted topology with a calculated strain energy of 73.9 kcal/mol per twist, highest among reported Möbius π-systems. Despite pronounced distortion, 1 retains a Clar-type localized electronic structure analogous to planar kekulene, with local aromaticity progressively perturbed toward the twist region. These results establish strain-trajectory programming as a design principle for accessing highly constrained molecular topologies.
Related
BibTeX
@misc{he2026möbius,
title = {{Möbius Kekulene}},
author = {Mingxin He and Yong Ni},
howpublished = {ChemRxiv},
year = {2026},
month = oct,
doi = {10.26434/chemrxiv.15010095/v1},
url = {https://chemrxiv.org/doi/full/10.26434/chemrxiv.15010095/v1},
note = {CC BY},
}
RIS
TY - UNPB
TI - Möbius Kekulene
AU - Mingxin He
AU - Yong Ni
PY - 2026
DA - 2026/10/08
PB - ChemRxiv
DO - 10.26434/chemrxiv.15010095/v1
UR - https://chemrxiv.org/doi/full/10.26434/chemrxiv.15010095/v1
AB - Encoding prescribed topologies in rigid conjugated frameworks offers a route to tuning electronic properties but is constrained by severe geometric strain. We synthesized and isolated Möbius kekulene, a compact, all-benzenoid double-stranded counterpart of planar kekulene. Its synthesis was enabled by strain-trajectory programming, in which precursor connectivity is designed to control strain accumulation during cyclization. Comparison of two precursors revealed contrasting strain trajectories: MCP1 concentrated the torsional deformation into an inaccessible late-stage closure, whereasMCP2 accommodated deformation progressively, reducing the largest strain increment and affording Möbius kekulene 1. Crystallography confirms a singly twisted topology with a calculated strain energy of 73.9 kcal/mol per twist, highest among reported Möbius π-systems. Despite pronounced distortion, 1 retains a Clar-type localized electronic structure analogous to planar kekulene, with local aromaticity progressively perturbed toward the twist region. These results establish strain-trajectory programming as a design principle for accessing highly constrained molecular topologies.
ER -