High-spin polynitroxide radicals as versatile bridging ligands for transition metal complexes with high ferri/ferromagnetic Tc

Abstract

π-Conjugated di- and trinitroxide radicals with triplet and quartet ground states, respectively, were allowed to react with manganese(II) bis(hexafluoroacetyl-acetonate) to give polymer complexes having well-defined structures. While a 1:1 1-D complex from the m-phenylenebis(nitroxide) 5 was found to be a metamagnet (TC = 5.5 K), 2:3 2-D and 3-D complexes from the trinitroxides 7-9 became ferri/ferromagnets with TC in the range 3.4 - 46 K. Design of these self-assembled heterospin systems with tailored dimensions and the sign and magnitude of the exchange coupling will serve as a useful strategy for exploring higher TC molecule-based magnets.