Synthesis and Characterization of New Polyaza Macrocyclic Nikel(￥±) and Copper(￥±)Complexes Containing Two Nitrile or Imidate Ester Pendant Arms:Metal-Mediated Hydrolysis and Alcoholysis of the Nitrile Group

摘要

New di-N-cyanomethylated tetraaza macrocycle 2,3-bis (cyanomethlyl)-5, 16- dimethyl-2,6,13,17-tetraazatri-cyclo [16.4.0.07.12] docosane (L2)) has been prepared by the reaction of the reaction of 3,14- dimethyl-2 ,6,13,17-tetraazatri-cyclo [16.4.0.07.12] docosane (L1) with bromoacetonitrile. The square-planar complexes [ML2](ClO₄) ₂ (M=Ni(ケ) or Cu(ケ)) can be prepared by the reaction of L2 with the corresponding metal ion in acetonitrile. The cyanomethyl groups of [ML2](ClO₄)₂ readily react with water to yield [ML3](ClO₄)₂ containing pendant amide groups. The trans-octahetral complexes [ML4](ClO₄)₂ , in which two imidate ester group are coordinated to the metal ion, can be also prepared by the reacton of [ML2](ClO₄)₂ with methanol under mild conditions. The hydrolysis and alcoholysis reaction of [ML2](ClO₄)₂ are promoted by the central metal ion , in spite of the fact that the cyanomethyl group is not invovled in intramolecular coordination. The reactons are also promoted by a base such as triethylamine but are retarded by an acid (HClO₄). Interestingly, the imidate ester groups of [ML4]2+ are unusually resistant to hydrolysis even in 0.1 M HClO₄ or 0.1M NaOH aqueous soluton. Crystal structure of [NiL4](ClO₄)₂ show that the Ni-N (pendant imidate ester group) bond is relatively strong; the Ni-N bond distance is shorter then the Ni-N (tertiary) distance and is similar to the Ni-N (secondary) distance.