Organic Ferromagnetism: Trapping Spins in the Glassy State of an Organic Network Structure

Abstract

The unique organic π-conjugated network structure was synthesized in trifluoromethanesulfonic acid at 155°C by self-polymerization of the tetracyanoquinodimethane (TCNQ) monomer in an efficient way. Highly stable free radicals achieved through the self-polymerization of TCNQ, these radicals originate from the 90° rotation of cyclohexadiene rings into phenyl rings and 120° ferromagnetic order around the triazine rings. The presence of unpaired electrons (radicals) in p-TCNQ was established by solid-state electron spin resonance spectroscopy, and the long-range magnetic ordering through the network was characterized by a Quantum Design SQUID-VSM. Designing and manipulating the spins in polymer networks via organic methodologies will provide alternative approaches for versatile future applications of plastic magnets.