<p>Verdazyl-nitroxide
diradicals were synthesized using the palladium-catalyzed cross-coupling
reaction of the corresponding iodoverdazyls with a nitronyl nitroxide-2-ide
gold(I) complex with high yields (up to 82%). The synthesized diradicals were
found to be highly thermally stable and have a singlet (D<i>E</i><sub>ST</sub> » -64 cm<sup>–1</sup>) or triplet ground state (D<i>E</i><sub>ST</sub> ³ 25 and 100 cm<sup>–1</sup>), depending on which
canonical hydrocarbon diradical type they belong to. Upon crystallization,
triplet diradicals form unique one-dimensional (1D) spin <i>S</i> = 1 chains of organic diradicals with intrachain ferromagnetic
coupling of <i>J</i>′/<i>k</i><sub>B</sub> from 3 to 6 K.</p>