Stereoregular radical polymers enable selective spin transfer.

Spintronic devices are emerging as an approach to realize performance and energy efficiency beyond what is possible with traditional electronic devices. State-of-the-art metals and doped conjugated polymers used for spin manipulation suffer from fundamental performance and stability issues. We leveraged stereoselective cationic polymerization to design a polymer with a stable persistent radical in each repeat unit that enables the long-range order necessary for spin transport. This approach overcomes conventional requirements for doping in organic spin-pumping devices while showcasing high conductivity, long spin-diffusion lengths, and processability. Molecular-level alterations in polymer stereochemistry were critical for controlling spin-spin interactions and alignment. Stereoregular polymers with persistent neutral radicals represent a previously unidentified class of materials for manipulating spins over long distances for applications in next-generation information storage.