Two New Cobalt(II) Heterotrispin Dimers Bridged by Functional Nitronyl Nitroxides: Structure and Magnetic Properties

Two cyclic dimer Co(II)-nitronyl nitroxide (NITR) complexes, [Co(hfac)2(NITmPh3Py)]2 (1) and [Co(hfac)2(NIToPh3Py)]2 (2) (NITmPh3Py = 2-[3-methoxyphenyl(3-pyridinyl)]-4,4,5,5-tetramethyl imidazoline−1-oxyl-3-oxide; NIToPy3Ph =2-[2-methoxyphenyl(3-pyridinyl)]-4,4,5,5-tetramethyl imidazoline−1-oxyl-3-oxide; hfac = hexaflfluoroacetylacetonate) have been successfully synthesized and characterized structurally and magnetically. Complex 1 crystallizes in the orthorhombi space group Pbcn with Z = 4, while complex 2 is in monoclinic space group P21/c with Z =2. The magnetic susceptibility studies show strong antiferromagnetic interactions between Co(II) ion and NITR radical in complexes 1 and 2.