New 2p-3d-4f chain compounds [LnZn(hfac)₅(NIT-Pyrim)₂] constructed from pyrimidine based nitronyl nitroxides

The 1:1:2 mixture of Ln(hfac)₃, Zn(hfac)₂, and NIT-Pyrim (hfac = hexafluoroacetylacetonate, NIT-Pyrim = 2-pyrimidine-4,4,5,5-tetramethylimidazoline-1-oxyl-3-oxide) afforded a series of 2p-3d-4f magnetic chains [Ln(hfac)₃Zn(hfac)₂(NIT-Pyrim)₂] [Ln^III = Gd (1), Ho (2), Yb (3)], in which Zn(hfac)₂ and Ln(hfac)₃ units are bridged by pyrimidine substituted nitronyl nitroxides through their NO moieties and pyrimidine nitrogen atoms. These complexes represent the first examples of 2p-3d-4f complexes with Zn^II ions. Magnetic studies show that there exist ferromagnetic exchange couplings between the coordinated NO groups of radical ligands and the Gd^III ions. (copyright 2018 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)