Jump to main content
Jump to site search

Issue 27, 2019
Previous Article Next Article

Relationship between solid state structure and solution stability of copper(ii)–hydroxypyridinecarboxylate complexes

Author affiliations

Abstract

The complementary solid state/solution studies of the systematic series of bioactive ligands 3-hydroxy-1-methyl-4-pyridinecarboxylate (L1), 3-hydroxy-1,2,6-trimethyl-4-pyridinecarboxylate (L2), 4-hydroxy-1-methyl-3-pyridinecarboxylate (L3), 4-hydroxy-1,6-dimethyl-3-pyridinecarboxylate (L4), 4-hydroxy-1-(2-hydroxyethyl)-6-methyl-3-pyridinecarboxylate (L5) and 4-hydroxy-1-(2-carboxyethyl)-6-methyl-3-pyridinecarboxylate (L6) with copper(II) have been performed in order to design efficient chelating drugs for the treatment of metal overloading conditions. Single crystals of [Cu(L1)2(H2O)]·3H2O (1) (monomer) with axial water coordination, [Cu2(L2)4]·6H2O (2) and [Cu2(L3)4]·4H2O (3) (cyclic dimers), where pyridinolato and carboxylato oxygens, respectively, act as linkers between adjacent copper complexes, [Cu(L4)2]n·3H2O (4) (1D polymer) and [Cu3(L5)6]·18H2O (5) (trimer), constructed using two square-pyramidal and one elongated octahedral Cu(II) complexes have been determined by SXRD. The bidentate coordination mode of the ligands has been found preferentially with cis arrangements in 1 and 2 and trans arrangements in 3–5. The solution speciation and complex stability of aqueous solutions have been studied by pH-dependent electron paramagnetic resonance spectroscopy resulting in the detection of solely monomeric [CuL]+ and [CuL2] complexes. The stability order obtained for the [CuL]+ complexes could be correlated with the deprotonation constants of their hydroxyl group (log βLH) reflecting that the higher acidity increases the complex stability in the order L2 < L1L6 < L4L5 < L3. This stability order elucidates the different axial linkers in the cyclic dimers 2 and 3. DFT quantum-chemical calculations support the effect of the electron distribution on the established stability order.

Graphical abstract: Relationship between solid state structure and solution stability of copper(ii)–hydroxypyridinecarboxylate complexes

Back to tab navigation

Supplementary files

Article information


Submitted
20 Mar 2019
Accepted
05 Jun 2019
First published
05 Jun 2019

This article is Open Access

New J. Chem., 2019,43, 10699-10710
Article type
Paper

Relationship between solid state structure and solution stability of copper(II)–hydroxypyridinecarboxylate complexes

N. V. May, G. T. Gál, Z. Szentendrei, L. Korecz, Z. May, M. G. Ferlin, A. Dean, P. Bombicz and V. B. Di Marco, New J. Chem., 2019, 43, 10699
DOI: 10.1039/C9NJ01469A

This article is licensed under a Creative Commons Attribution 3.0 Unported Licence. Material from this article can be used in other publications provided that the correct acknowledgement is given with the reproduced material.

Reproduced material should be attributed as follows:

  • For reproduction of material from NJC:
    [Original citation] - Published by The Royal Society of Chemistry (RSC) on behalf of the Centre National de la Recherche Scientifique (CNRS) and the RSC.
  • For reproduction of material from PCCP:
    [Original citation] - Published by the PCCP Owner Societies.
  • For reproduction of material from PPS:
    [Original citation] - Published by The Royal Society of Chemistry (RSC) on behalf of the European Society for Photobiology, the European Photochemistry Association, and RSC.
  • For reproduction of material from all other RSC journals:
    [Original citation] - Published by The Royal Society of Chemistry.

Information about reproducing material from RSC articles with different licences is available on our Permission Requests page.


Social activity

Search articles by author

Spotlight

Advertisements