Hirotaka NAGAO (Sophia Univ.), Nobutoshi KOMEDA, Masao MUKAIDA (Sophia Univ.), Masatatsu SUZUKI (Kanazawa Univ.) and Koji TANAKA
[Inorg. Chem. 35, 6809 (1996)]
A series of copper(II) complexes with tripodal polypyridylmethylamine ligands, such as tris(2-pyridylmethyl)amine (tpa), (6-methyl-2-pyridylmethyl)bis(2-pyridylmethyl)amine (Me1tpa), bis(6-methyl-2-pyridylmethyl)(2-pyridylmethyl)amine (Me2tpa), and tris(6-methyl-2-pyridylmethyl)amine (Me3tpa), have been synthesized and characterized by X-ray crystallography: [Cu(H2O)(tpa)](ClO4)2 (1) crystallized in the monoclinic system, space group P21/a, with a = 15.029(7) Å, b = 9.268(2) Å, c = 17.948(5) Å, (beta) = 113.80(3)°, and Z = 4. [CuCl-(Me1tpa)]ClO4 (2) crystallized in the triclinic system, space group P 1, with a = 13.617(4) Å, b = 14.532(4) Å, c = 12.357(4) Å, (alpha) = 106.01(3)°, (beta) = 111.96(2)°, (gamma) = 71.61(2)°, and Z = 4. [CuCl(Me2tpa)]ClO4 (3) crystallized in the monoclinic system, space group P21/n, with a = 19.650(4) Å, b = 13.528(4) Å, c = 8.55(1) Å, (beta) = 101.51(5)°, and Z = 4 (R = 0.071, Rw = 0.050). [CuCl(Me3tpa)]-[CuCl2(Me3tpa)]ClO4 (4) crystallized in the monoclinic system, space group P21/a, with a = 15.698(6) Å, b = 14.687(7) Å, c = 19.475(4) Å, (beta) = 97.13(2)°, and Z = 4. 1-4 are penta-coordinate geometries with three pyridyl and one tertiary amino nitrogen atoms, and a chloride or aqua oxygen atom. Nitrite ion coordinated to the Cu(II) center of Me1tpa, Me2tpa, and Me3tpa complexes with only oxygen atom to form nitrito adducts, and the catalytic activity for the reduction of NO2- increases in the order of Me3tpa << Me2tpa << Me1tpa < tpa complexes.