Bis{1-n-hexyl-3-methyl-4-[1-(phenylimino)propyl]-1H-pyrazol-5-olato}copper(II): a new copper(II) complex with a chelating alkylpyrazolone-based enamine.

The title compound, [Cu(C19H26N3O)2], is the first reported complex of the alkylpyrazolone-derived ligand 1-n-hexyl-3-methyl-4-[1-(phenylimino)propyl]-1H-pyrazol-5(4H)-one. The most notable feature is the imine-enol character presented by the ligand due to coordination, in spite of its enamine-ketone structure in the free state. The ligand chelates through N and O atoms, resulting in a square-planar coordination around the CuII atom, which lies on an inversion centre.