Triamino-s-triazine triradical trications. An experimental study of triazine as a magnetic coupling unit

[structure: see text] Triamino-s-triazine derivatives 3a, 4, and 5 have been prepared, and their cationic states have been analyzed electrochemically. At 298 K, 3a+ has a limited lifetime in CH2Cl2 solution. However, 4+ and 5+ are long-lived under such conditions, and quartet states of 4(3+) and 5(3+) are observed by ESR spectroscopy. Variable-temperature ESR analysis and NMR shift susceptibility measurements indicate that 5(3+) is a doublet ground state with a populated quartet state.