Search

Methods for the synthesis of a new family of nitronylnitroxides, iminonitroxides, and their precursors with 2-hydroxyphenyl or 3-hydroxypyridin-2-yl substituents in the side chain have been developed. Five heterospin chelates of Cu(II) with deprotonated iminonitroxides have been isolated. Their structure and magnetic properties have been studied. In all complexes, ferromagnetic intramolecular exchange interactions take place (J∼40–350 cm−1).

Metal complexes with stable radicals form a continuous series of solid solutions Ni x Co 1− x L 2 (CH 3 OH) 2 , Ni x Co 1− x L 2 (C 2 H 5 OH) 2, and Ni x Co 1− x L 2 (HO(CH 2 ) 4 OH), where L is a deprotonated enaminoketone derivative of 3-imidazoline nitroxide. Variation of x does not affect the structural parameters of layered polymeric Ni x Co 1− x L 2 (CH 3 OH) 2 and Ni x Co 1− x L 2 (C 2 H 5 OH) 2 and framework Ni x Co 1− x L 2 (HO(CH 2 ) 4 OH) but leads to smooth variation of the magnetic transition temperature and effective magnetic moment. Spontaneous magnetization is anomalous in the range x ∼0.8–0.9, where it tends to zero because the spontaneous magnetic moment of the ‘nickel sublattice’ is compensated by the spontaneous moment of the ‘cobalt sublattice’.