Symmetry‐Breaking in Carbon Nanohoops Enables Room‐Temperature Ternary Single‐Molecule Switching

Abstract Single‐molecule electronics offers chemically encoded routes to ultra‐dense information processing, yet room‐temperature operation is often limited to binary conductance states due to thermal broadening and electronic averaging. Here we demonstrate robust ternary switching at room temperature using symmetry‐engineered carbon nanohoops. Embedding a pyrene unit into the [12]cycloparaphenylene backbone via a symmetry‐breaking 1,6‐linkage disrupts the electronic equivalence of π –segments and localizes frontier orbitals. Under controlled mechanical elongation in single–molecule junctions, the molecule exhibits three well‐resolved conductance plateaus, each separated by ∼one order of magnitude, affording unambiguous and reproducible readout. First‐principles transport calculations reveal that symmetry‐breaking–induced orbital localization discretizes coherent tunneling pathways, accounting for the observed plateaus. These findings establish molecular symmetry control as a general design principle for room‐temperature multistate charge transport in conjugated macrocycles, opening a pathway to high‐density single‐molecule logic architectures.