Ligands designed to impose tetrahedral co-ordination: a convenient route to aminoethyl and aminopropyl pendant arm derivatives of 1,5,9-triazacyclododecane

Abstract

The macrocyclic ligands 1-(2-aminoethyl)-(L¹) and 1-(3-aminopropyl)-1,5,9-triazacyclododecane (L²) have been synthesised from 2,4-dioxo-1,5,9-triazacyclododecane, and the complexes [ZnL¹(OClO₃)]ClO₄(trigonal bipyramidal) and [NiL²(NCS)₂](octahedral) characterised by X-ray crystallography; L¹ and L² form more stable complexes than do analogues bearing tertiary amino groups on the pendant arms, but allow higher co-ordination numbers.