Syntheses, crystal structures, and magnetic properties of two cyclic dimer M2L2 complexes constructed from a new nitronyl nitroxide ligand and M(hfac)2 (MÂ =Â Cu2+, Mn2+)

The new long nitronyl nitroxide radical ligand, 2-[4-(5-pyrimidyl)phenyl]-4,4,5,5-tetramethylimidazoline-1-oxyl-3-oxide (4-NITPhPyrim), was successfully utilized to construct two new cyclic dimer M2L2 magnetic complexes [Cu(hfac)2(4-NITPhPyrim)]2 · 4H2O (hfac− = hexafluoroacetylacetonate) (1) and [Mn(hfac)2(4-NITPhPyrim)]2 · 4H2O (2).