Jump to main content
Jump to site search

Issue 40, 2012
Previous Article Next Article

A novel di-compartmental bis-(2-hydroxyisophtalamide) macrocyclic ligand and its mononuclear Cu(ii) and Ni(ii) complexes

Author affiliations

Abstract

The synthesis and characterisation of the new di-compartmental bis-(2-hydroxyisophtalamide) macrocyclic pro-ligand, LH6, which comprises two phenol-diamide units linked by ethylene bridges, is herein reported, together with its corresponding di-phenolate salt, [NBu4]2[LH4]. The three macrocyclic compounds, [LH4(OMe)2] (protected ligand), LH6 and [LH4][NBu4]2 were fully characterised including X-ray crystallography for [LH4(OMe)2] and [NBu4]2[LH4]. The results of solid-state and solution studies have indicated that the macrocycle can adopt specific conformations, which are influenced by H-bonding interactions as well as the deviation of the amide carbonyl relative to the phenol plane. LH6 reacts with MII(acetate)2·(H2O)6 (M = Ni, Cu) in a 1 : 1 ratio in the presence of 4 eq of [NBu4](OH) in methanol to afford the dianionic [M(LH2)]2− complexes, 12− and 22−, respectively. The X-ray crystallography, EPR, NMR and UV-vis spectroscopic data, combined with DFT calculations, indicate that 12− and 22− are unique unsymmetrical square planar mononuclear complexes that are intramolecularly H-bonded. Thus, one macrocyclic compartment contains a MII–N2O2 centre resulting from the tetra-anionic di-phenolato di-amidato ligation; the other compartment possesses two protonated amide N–H groups that are H-bonded the coordinated phenolate O atoms. This represents a unique example in which a phenolate is both coordinated and intramolecularly H-bonded. This H-bonding appears unusually strong as revealed by N(H/D) exchange experiments; and may be responsible for the stability of the mononuclear complex, and the difficulty in isolating the corresponding dinuclear complex [M2(L)]2−.

Graphical abstract: A novel di-compartmental bis-(2-hydroxyisophtalamide) macrocyclic ligand and its mononuclear Cu(ii) and Ni(ii) complexes

Back to tab navigation

Supplementary files

Publication details

The article was received on 17 Jul 2012, accepted on 08 Aug 2012 and first published on 08 Aug 2012


Article type: Paper
DOI: 10.1039/C2DT31586F
Dalton Trans., 2012,41, 12457-12467

  •   Request permissions

    A novel di-compartmental bis-(2-hydroxyisophtalamide) macrocyclic ligand and its mononuclear Cu(II) and Ni(II) complexes

    M. Eckshtain-Levi, R. Lavi, D. Yufit, M. Orio, R. Wanke and L. Benisvy, Dalton Trans., 2012, 41, 12457
    DOI: 10.1039/C2DT31586F

Search articles by author

Spotlight

Advertisements