Zinc(II) complexes of some cyclic tetra-amines - some zinc(II) complexes of 5,7,7,12,14,14-hexamethyl-1,4,8,11-tetra-azacyclotetradeca-4,11-diene and C-meso- and C-rac-(5,7,7,12,14,14-hexamethyl-1,4,8,11- tetra-azacyclotetradecane)

Abstract

The purpose of this work was to synthesize, analyse, and determine the configuration and structure of some of the zinc(II) complexes of two isomeric, macrocyclic tetra-amrine ligands: C-meso-and C-rac-5,7,7,12,14,14-hexamethyl-1,4,8,11-tetra-azacyclotetradecane, abbreviated to "mesotet" and "ractet" (referred to in some previous papers as "tet-a" and "tet-b" respectively); and the Schiff base macrocyclic imine from which they are derived by reduction of the imine double bonds: 5,7,7,12,14,14-hexamethyl-1,4,8,11-tetra-azacyclotetradeca-4,11-diene abbreviated to "diene", (also referred to in the literature as "trans-[14]-diene"). (see Figure 1-1 for nomenclature). The only zinc(II) complex of any of these three ligands which has previously been reported was formulated as [Zn(diene)(H2O)Cl]ClO4. (1) The authors gave no justification for the octahedral formulation and, although this compound was not prepared in the present work, evidence suggests that the five-co-ordinate structure [Zn(diene)Cl]ClO4.H2O is more likely.