Stereochemistry of Radical Polymers in Charge and Spin Transport

Stable open-shell materials are increasingly recognized as promising systems for organic electronic and spintronic applications. While most work has focused on common conjugated polymers with ill-defined structures, relatively little attention has been given to the role of stereochemistry in influencing charge and spin transport properties. Here, various stereoregular oxoverdazyl radical polymers were synthesized with a flexible synthetic approach to push the bounds associated with the fundamental physics that underly charge and spin transport. These polymers, featuring persistent radicals in each repeat unit, were engineered to achieve the long-range order essential for efficient charge and spin transport. Furthermore, the meso-rich variants with enhanced alignment between active radicals lead to improved charge conductivity and increased spin-diffusion lengths. Notably, the observed distinctive reversal in output voltage for the well-confined conformation illustrates molecular-level structural control encompassing the inverse spin Hall effect in organic radical-based spintronics. These structural properties highlight the interplay between stereochemistry and transport characteristics, thereby offering useful insights into the design of superior materials for spintronics applications. Thus, this study provides a potential framework for deriving strategies to exploit stereoregularity for improved charge and spin movement in radical polymers, bridging the concepts in polymer physics and novel material design.