A zinc(II) nitrate complex with tripod ligand tris(2-benzimidazolylmethyl)amine and 2-methacrylate

A new ternary complex of zinc(II) with tris(2-benzimidazolylmethyl)amine (ntb) and 2-methacrylate, {[Zn(ntb)-(2-methacrylate)](NO(3))}(2) (H(2)O), was synthesized and characterized by elemental and thermal analyses, electrical conductivity, IR, UV/visible, and (1)H-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 N(4)O ligand set. The coordination geometries of the zinc ion may be best described as a distorted trigonal bipyramid [Zn(1) tau = 0.84, Zn(2) = 0.91], with approximate C(3) molecular symmetry.