Synthesis and magnetic properties of novel nitronyl nitroxides: racemic 2-phenyl-4-alkyl-4,5,5-trimethyl-4,5-dihydro-1H-imidazolyl-1-oxyl-3-oxide

Novel chiral nitronyl nitroxides having various substituents such as alkyl, alkoxymethyl, silyloxymethyl and acyloxymethyl groups at C(4) position of the imidazole ring were synthesized as the racemates. Magnetic properties of the obtained nitroxides were characterized by means of EPR spectroscopy and SQUID susceptometry. All the obtained nitroxides obeyed Curie–Weiss law and showed very weak anti-ferromagnetic interactions at low temperatures. Their Weiss constants (θ) were estimated to be −1 to 0 K.