A Zinc(II) Nitrate Complex with Tripod Ligand Tris(2-benzimidazolylmethyl)amine and 2-Methacrylate

Abstract

A new ternary complex of zinc(II) with tris(2-benzimidazolylmethyl)amine (ntb) and 2-methacrylate, {[Zn(ntb)-(2-methacrylate)](NO3)}2 (H2O), was synthesized and characterized by elemental and thermal analyses, electrical conductivity, IR, UV/visible, and 1H-n.m.r. spectra. The crystal structure of the complex has been determined by the single-crystal X-ray diffraction. In the complex, ntb functions as a tripod tetradentate ligand, resulting in trigonal pyramidal geometry. An additional ligand, 2-methacrylate, is coordinated at the opened site trans to the apical nitrogen aton of the ntb ligand. The crystal structure of the zinc complex shows two crystallographically independent but chemically identical [Zn(ntb)(2-methacrylate)]+ cations. The zinc ion is 5-coordinate with an N4O ligand set. The coordination geometries of the zinc ion may be best described as a distorted trigonal bipyramid [Zn(1) τ = 0.84, Zn(2) τ = 0.91], with approximate C 3 molecular symmetry.