Abstract
The tetramethylammonium and potassium salts of [1,2-bis(2-oxybenzamidato)benzene]copper(II) abbreviated as [NMe4]2[Cu(hbab)] and K2[Cu(hbab)] were prepared and characterized. The x-ray analysis of the potassium salt, K2[Cu(hbab)]·5DMF, revealed a unique one-dimensional chain structure consisting of {[KO3][K(Cu(hbab)O]}n as the resulting unit, where each K+ ion is surrounded octahedrally by six oxygen atoms and all the oxygen atoms play the role of a bridging group to the K+ ion. The tetramethylammonium salt, [NMe4]2[Cu(hbab)]·H2O, behaves as a 2 : 1 electrolyte in the 10-3 mol dm-3 solutions of methanol, acetonitrile and DMF, while the potassium salt behaves as a 2 : 1 electrolyte in methanol and as a 1 : 1 electrolyte in acetonitrile and DMF. The CuII/III redox potentials of the tetramethylammonium salt in DMF under the presence of 2 equivalent molar of K+, Na+, and Li+ shift to more positive values than those without alkali metal ions, where the magnitude of the positive shift increases with increasing of charge density of alkali metal ion, namely Li+ > Na+ > K-. The charge effect due to ion pair formation between [Cu(hbab)]2- and Na+ or K+ causes the potential shift, while the potential shift in the case of the Li+ ion is brought about by the decrease of donor ability of the phenolic oxygens, besides the charge effect.
Original language | English |
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Pages (from-to) | 4105-4111 |
Number of pages | 7 |
Journal | Polyhedron |
Volume | 16 |
Issue number | 23 |
DOIs | |
Publication status | Published - Sep 1997 |
Externally published | Yes |
Keywords
- Counter cation effect
- Crystal structure
- Electrochemical property
- Ion pair formation
- Solvent effect
ASJC Scopus subject areas
- Physical and Theoretical Chemistry
- Inorganic Chemistry
- Materials Chemistry