Slow Relaxation of the Magnetization of an MnIII Single Ion

A Mn-III-salen-type complex with a diamagnetic [Co-III(CN)(6)](3-) moiety, [Mn-III(5-TMAM(R)-salmen)(H2O)Co-III(CN)(6)]center dot 7H(2)O center dot MeCN [1; 5-TMAM(R)-salmen = (R)-N,N'-(1-methylethylene)bis(5-trimethylammoniomethylsalicylideneiminate], was prepared. From direct-current magnetic susceptibilities, magnetization, and high-field and multifrequency electronic spin resonance measurements on powdered samples, 1 has a significant uniaxial anisotropy. Frequency-dependent alternating. current susceptibility signals were clearly observed, indicating slow magnetic relaxation. Thus, complex 1 behaves as a single-ion magnet.