Platform for High-Spin Molecules: A Verdazyl-Nitronyl Nitroxide Triradical with Quartet Ground State

Quartet verdazyl-nitronylnitroxide triradical was synthesized via palladium-catalyzed cross-coupling reaction of the corresponding diiodoverdazyls with a nitronyl nitroxide-2-ide gold(I) complex. The triradical is air-stable and possess good thermal stability with decomposition onset at ∼160 °C in an inert atmosphere. X-ray diffraction analysis of single crystals confirmed the presence of verdazyl and nitroxide radical centers. Magnetic properties were characterized by a SQUID magnetometry of polycrystalline powders and by EPR spectroscopy in different matrices. Collected data analyzed using of the high-level quantum chemical calculations confirmed that the triradical has high-spin ground states.