Synthesis and properties of the complexes of lanthanides with nitronyl nitroxide biradical

Five novel complexes of formula Ln(hfac)₃] · BNPhOM, where La = Gd, Ho, Dy, Y, Er; Mac = hexfluoracetylacetonate; BNPhOM=1,3‐bis‐2,2′,‐(4,4,5,5‐tetramethyl‐4,5‐di‐hydro‐1H‐imidazolyl‐1‐oxyl‐3‐oxide) phenoxy] propane, have been prepared and characterized by elemental analysis, molar conductances, IR and electronic spectra. The temperature dependence of the magnetic susceptibility for Gd(III) and radical was measured (2—‐300 K). The observed data were successfully simulated giving the exchange integral J = 0.28 cm^?1, J' = ‐ 0.33 cm^?1. These results indicate a weak ferromagnetic spin exchange interaction between Gd(III) ion and the radical and a weak antiferromagnetic spin exchange interaction between the radical and radical.