The crystal structure of a nickel(IIl) complex with meso-5,5,7,12,12,14-hexamethyl-1,4,8,11-tetraazacyclotetradecane, [Ni^IIICl₂(Me₆[14]aneN₄)]ClO₄

The crystal structure of a nickel(III) complex with meso-5,5,7,12,12,14-hexamethyl-1,4,8,11-tetraazacyclotetradecane (=Me₆[14]aneN₄), [Ni^IIICl₂(Me₆[14]aneN₄)]ClO₄, has been determined by single crystal X-ray diffraction method. The complex crystallizes in the monoclinic space group A2/a with a=15.634(1), b=6.5378(6), c=21.707(2) Å, β=92.29(1)° and Z=4. The nickel atom is surrounded octahedrally by four nitrogens and two chloro atoms in the trans form. The macrocyclic ligand adopts the most stable conformation and the total stereochemistry is the same as that of the corresponding Ni(II) analog, trans-[Ni^IICl₂(Me₆[14]aneN₄)]. The coordination bond lengths of this compound are significantly shorter than those in the Ni(II) analog, but a little longer than those of [Ni^IIICl₂([14]aneN₄)]ClO₄ which has no methyls in the macrocyclic ligand. These results are consistent with those of the ESR and electronic spectra previously reported.