Synthesis, crystal structure and intermolecular magnetic interactions of a new N-TEMPO-3,5-di-tert-butylsalicylaldimine radical

摘要

A new N-TEMP0-3,5-di-tert-butylsalicylaldimine radical (1) has been synthesized and characterized by single crystal X-ray diffraction, elemental analysis, IR, UV-vis, and EPR spectroscopy and temperature dependent magnetic susceptibility. X-ray diffraction revealed that H-atoms of γ-CH in TEMPO and CH_3 in salicylaldimine moieties, are located in close contact with the neighboring N-0 radical group in crystal 1. The temperature dependence of the magnetic susceptibility (xm) of 1 has been fitted by the Curie-Weiss law with θ = -0.3 K within 10-300 K, suggesting the presence of a weak intermolecular antiferro-magnetic interaction between radical centers at T < 10 K. It has been demonstrated that radical 1 possesses crystal structure involving co-existence of antiferromagnetic and ferromagnetic interactions through C-H---O-N contacts of γ-CH and ~tBu groups hydrogen atoms, in which the former path dominates over the latter.