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Updated: Jun 6, 2025

Construction and Systematical Symmetric Studies of a Series of Supramolecular Clusters with Binary or Ternary Ammonium Triphenylacetates
Published on: February 15, 2016
Single-Molecule Resolved Conformational and Orbital Symmetry Breaking in Tetraphenylethylene-Based Macrocycles
En Li1, Tao Lin2, Songshan Dai3
1Department of Physics, The Hong Kong University of Science and Technology, Clear Water Bay, Hong Kong 999077, China.
Abstract:
Tetraphenylethylene (TPE) is a prototype aggregate-induced emission molecule. TPE-based conjugated macrocycles exhibit unique optical properties due to their peculiar cyclic topology. Because the symmetry of macrocycles strongly affects their photophysical properties, here we report a single-molecule study of the structures and orbitals of two TPE-based macrocycles of (C26H18)4 and (C26H18)6. Using scanning tunneling microscopy and spectroscopy, we discover that both macrocycles undergo spontaneous symmetry breaking in their conformations and frontier orbitals. The computational analyses reveal that the symmetry breaking is driven by a subtle interplay of higher extended conjugation between phenyl and node carbon atoms and conformation flexibility of the macrocycles. The observed symmetry breaking in TPE-based macrocycles is expected to strongly alter their photophysical properties.
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