Hybrid magnetic solids of radical-substituted heteroaromatic compounds with metal halides

Complexes of manganese(II), cobalt(II), nickel(II), and copper(II) chlorides with 5-pyrimidinyl nitronyl nitroxide (5PMNN) and pyrazinyl nitronyl nitroxide (PZNN) were synthesized. Ni- and CoCl2·(5PMNN)2 showed magnetic phase transitions at 5.8 and 2.3 K, respectively, and spin–flip behavior below the transition temperatures. X-ray crystal structure analyses revealed that Mn- and CoCl2·(PZNN)2 were mononuclear.