High-Spin Donor-Acceptor Conjugated Polymers

Optoelectronic technologies based on organic semiconductors (OSCs) have witnessed a dramatic increase in recent decades, with impressive demonstrations of new functionality, devices, and commercial applications, largely based on donor-acceptor conjugated polymers (DA CPs). Open-shell and high-spin configurations bring new notions of spin manipulation, magnetism, quantum properties and interrelated optoelectronic functionalities at the forefront of research efforts in diverse fields. Although extensively studied, the intrinsic instability of these electronic configurations complicates synthesis and precludes an understanding of how fundamental properties manifest in practical applications. To this end, we have implemented new macromolecular design paradigms and strategies to control orbital topology such that very low bandgap DA CPs were synthesized in order to yield open-shell species in singlet (S = 0) and triplet (S = 1) spin states. Electron spin resonance (ESR) and superconducting quantum interference device magnetometry (SQUID) studies are critical to provide insight into ground state of these system and in the exploration of new phenomena derived from electron correlation in related materials.