A new oxo-azamacrocyclic ligand: 13,27-dimethyl-6,20-dioxa-3,9,17,23-tetraaza-tricyclo[23.3.1.1(11,15)]tria conta-1(29),11,13,15(30),25,27-hexaene-29,30-diol, and a dinuclear copper(II) complex: syntheses, characterization and binding ability

摘要

A new dinucleating tetraaza-dioxo-diphenol macrocyclic ligand: 13,27-dimethyl-6,20-dioxa-3,9,17,23-tetraaza-tricyclo[23.3.1.1(11,15)]tria conta-1(29),11, 13,15(30),25,27-hexaene-29,30-diol (L or BDOD) was synthesized and characterized. This ligand serves as the N4O42- motif for cation ions. The binding constants of divalent copper were determined using direct potentiometric titration. The logarithm formation constants of copper complexes are: log[CuL] = 22.62 and log[Cu2L] = 15.74. This macrocyclic ligand acts as the host to accommodate two copper ions at same time. The dinuclear copper complex were determined to be a central symmetric molecule with the formation of Cu2O2 bridge. Bond lengths of Cu-O(phenol) is 1.952 Angstrom, which is shorter than that of Cu-O(2) 2.368 Angstrom consistent with the expected Jahn-Teller distortion. Cu-N(av.) is 1.998 Angstrom. The coordination polyhedron of each copper ion is a slightly distorted square pyramid. (C) 2002 Published by Elsevier Science B.V. [References: 8]