Effects of Enhanced Spin Delocalization in Blatter’s Radical

Polymers and small molecules that bear open-shell, stable organic radical groups have proven to be quite beneficial in myriad organic electronic materials and device applications (e.g., magnetic systems and energy storage and energy conversion devices). The highly tunable optoelectronic properties of these materials, the potential for low-temperature processing, and the compatibility of these organic materials with flexible, mechanically-robust substrates distinguish radical polymers from their oft-used inorganic counterparts. However, because of their bourgeoning nature, many questions regarding the physics of their solid-state charge transfer mechanism still exist. To answer said questions we employed the 1,3-diphenyl-1,4-dihydro-1,2,4-triazin-4-yl radical (i.e., Blatter’s radical), which is a stable conjugated radical, in order to evaluate the charge transport mechanics in radical small molecules and macromolecules. Moreover, we characterized the impact of enhanced spin delocalization, facilitated through extended conjugation of the molecular architecture, in relation to charge transport physics. These results provide experimental insights into the mechanism of solid-state electrical conduction in radical-containing small molecules and polymers.