Synthesis and characterization of CoIII3 inverse metallacrowns via use of 6-methyl-2-pyridylaldoxime

The use of 6-methyl-2-pyridylaldoxime (6-mepaoH) in cobalt carboxylate chemistry has yielded metallacrowns with general formula [CoIII3(μ3-O)(O2CMe)3(6-mepao)3]2[CoII(L)4] (1⋅ 2MeOH ⋅ 1.5H2O, L = AcO− and 2⋅ 2.5H2O, L = NCS−). Compounds 1 and 2 display an unusual structural motif in cobalt-oximate chemistry, consisting of CoIII triangles centered by one μ3-oxo ligand. Crystal structure and EPR characterization of CoII anions are reported.