Crystal structures and spectroscopic properties of copper(II) and zinc(II) complexes with the macrocycle 1,4,7-tris(2-pyridylmethyl)-1,4,7-triazacyclononane

Two novel transition-metal copper and zinc complexes [(CuL)₂]·(ClO₄) (1) and [(ZnL)]·(ClO₄)₂ (2) (L = 1,4,7-tris(2-pyridylmethyl)-1,4,7-triazacyclononane) have been synthesized and structurally determined. The two complexes are both crystallized in monoclinic space group P2(1)/c with a = 14.318(4), b = 17.214(5), c = 22.403(7) Å, = 93.096(6)°, V = 5522(3) ų, and Z = 4 for 1 and a = 9.371(2), b = 17.615(4), c = 17.579(4) Å, =104.070(4)°, V = 2814.6(11) ų, and Z = 4 for 2. The center metal ions are coordinated to six nitrogen atoms, three of which are from triazacyclononane and other three from the pendant-arms 2-pyridylmethyl, forming a slightly distorted octahedral geometry. Two complexes have been characterized by element analysis, infrared spectroscopy, and the UV–Vis and ESR spectra for 1 have also been determined.