Poly‑<i>p</i>‑hydroquinone Ethers: Isoenergetic Molecular Wires with Length-Invariant Oxidation Potentials and Cation Radical Excitation Energies

Typical poly-<i>p</i>-phenylene wires are characterized by strong interchromophoric electronic coupling with redox and optical properties being highly length-dependent. Herein we show that an incorporation of a pair of <i>para</i>-methoxy groups at each <i>p</i>-phenylene unit in poly-<i>p</i>-phenylene wires (i.e., <b>PHE</b>_<i>n</i>) changes the nodal structure of HOMO that leads to length-invariant oxidation potentials and cation radical excitation energies. As such, <b>PHE</b>_<i>n</i> represents a unique class of isoenergetic wires where hole delocalization mainly occurs via dynamic hopping and thus may serve as an efficient medium for long-range charge transfer. Availability of these wires will allow demonstration of long-range electron transfer via incoherent hopping using donor-bridge-acceptor systems with isoenergetic <b>PHE</b>_<i>n</i>-based wires as bridges