Ferromagnetic interaction between nitronyl nitroxide radical cations in a semiconducting salt

The crystal and magnetic structure of the 1:1 salt of Ni(dmit)2 (dmit=l,3-dithiol-2-thione-4,5-dithiolate) anionic radical and pEPYNN(p-N-ethylpyridinium α-nitronyl nitroxide) cationic radical has been studied. Ferromagnetic interaction with J/kB = 0.16 K has been found to operate in the one-dimensional p-EPYNN chains, while the first molecular antiferromagnetic spin ladder has been found to form in the Ni(dmit)2 chains.