Organic di- and trinitroxide radicals with triplet and quartet ground states, respectively, were allowed to react with manganese(a) bis(hexafluoroacetylacetonate) to give polymer complexes having well-defined dimensionality. While 1:1 1-D complex from the m-phenylenebis(nitroxide) was found to be a metamagnet (T-C = 5.5 K), 2:3 2-D complexes from the trinitroxides became ferri/ferromagnets with Te in the range 3.4 - 46 K, demonstrating the merit of these heterospin systems as a design strategy for molecule-based magnets.