Jump to main content
Jump to site search
Access to RSC content Close the message box

Continue to access RSC content when you are not at your institution. Follow our step-by-step guide.


Issue 6, 2013
Previous Article Next Article

Low symmetry pyrazole-based tripodal tetraamineligands: metal complexes and ligand decomposition reactions

Author affiliations

Abstract

The new low symmetry pyrazole-based tripodal tetraamine ligands 2-(1H-pyrazol-1-yl)-N,N-bis(1H-pyrazol-1-ylmethyl)ethanamine (bmpz) and 2-(1H-pyrazol-1-yl)-N-[2-(1H-pyrazol-1-yl)ethyl]-N-(1H-pyrazol-1-ylmethyl)ethanamine (bepz) have been prepared and characterised, as have metal complexes containing these ligands. X-ray crystal structures of [Co(bmpz)Cl]2[CoCl4]·H2O, [Co(bmpz)MeCN](ClO4)2·0.13H2O, [Zn(bmpz)MeCN](ClO4)2·0.15H2O, [Zn(bepz)OH2](ClO4)2·0.5H2O and [(Co(bepz)Cl)2]Cl2·6H2O confirm coordination of the intact tripodal ligands to the metal ions through all four N atoms. However, attempts to make Cu2+ complexes containing bmpz and bepz gave, respectively, [Cu(7)Cl2]·0.2H2O and [Cu(8)Cl2] (7 = 1-(1H-pyrazol-1-yl)-N-(1H-pyrazol-1-ylmethyl)ethanamine, 8 = 2-(1H-pyrazol-1-yl)-N-[2-(1H-pyrazol-1-yl)ethyl]ethanamine), complexes containing the tridentate ligands 7 and 8 which are formed by loss of a pyrazolylmethyl arm from the appropriate tripodal ligand. This decomposition reaction occurs in protic solvents both in the presence and absence of metal ions, and is ascribed to the presence of an aminal functionality in the tripodal ligands. A possible mechanism for the decomposition, based on NMR and ESMS data, is suggested.

Graphical abstract: Low symmetry pyrazole-based tripodal tetraamine ligands: metal complexes and ligand decomposition reactions

Back to tab navigation

Supplementary files

Article information


Submitted
21 Sep 2012
Accepted
16 Nov 2012
First published
16 Nov 2012

Dalton Trans., 2013,42, 2174-2185
Article type
Paper

Low symmetry pyrazole-based tripodal tetraamine ligands: metal complexes and ligand decomposition reactions

J. R. Cubanski, S. A. Cameron, J. D. Crowley and A. G. Blackman, Dalton Trans., 2013, 42, 2174
DOI: 10.1039/C2DT32200E

Social activity

Search articles by author

Spotlight

Advertisements