Four novel nanometer-sized cobalt azametallacrown complexes†
Four nanometer-sized cobalt azametallacrowns, [Co6(C8H6N3O3)6(CH3OH)6]·10CH3OH·2H2O (1), [Co6(C8H5N2O3)6(CH3OH)6]·5CH3OH·0.5H2O (2), [Co6(C9H7N2O3)6(CH3OH)6]·6CH3OH (3), and [Co6(C10H9N2O3)6(CH3OH)6]·7CH3OH·2H2O (4) have been synthesized by the self-assembly reaction of cobalt ions with N-substituted salicylhydrazide ligands. The cobalt atoms in the four azametallacrowns adopt a propeller configuration. The chiralities of the cobalt atoms alternate between the Λ and Δ forms. In 1, there are two encapsulated methanol solvent molecules in the ‘host’ cavity of the azametallacrown molecule, whereas in 2–4 there are no guest molecules in the ‘host’ cavities of the azametallacrowns.