Novel voltammetric responses of a 1,1 '-ferrocene bis(methylene aza-18-crown-6) receptor to group 1 and 2 metal cations in acetonitrile
A 1,1′-ferrocene bis(methylene aza-18-crown-6) ligand (L) and its inclusion complexes with Na+, K+, Ba2+ and Mg2+ are studied in acetonitrile by cyclic and square wave voltammetry. The ligand-metal complex stoichiometry is found to vary from 1:1 to 1:2 with increasing concentration of the metal cati...
| المؤلفون الرئيسيون: | , , |
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| التنسيق: | Journal article |
| اللغة: | English |
| منشور في: |
1998
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| الملخص: | A 1,1′-ferrocene bis(methylene aza-18-crown-6) ligand (L) and its inclusion complexes with Na+, K+, Ba2+ and Mg2+ are studied in acetonitrile by cyclic and square wave voltammetry. The ligand-metal complex stoichiometry is found to vary from 1:1 to 1:2 with increasing concentration of the metal cation. There is also a binding selectivity for dications over monocations. Simultaneous addition of Mg2+ and Ba2+ gives rise to a novel voltammetric feature which is rationalised by the formation of three different species; the symmetrical homobimetallic complexes, L-2Ba2+ and L-2Mg2+, and the asymmetrical heterobimetallic complex, L-Ba2+-Mg2+. L is therefore a redox active receptor capable of the simultaneous electrochemical recognition of different metal cations. An electrostatic model is proposed to account for the observed changes in the mean potential of L upon cation complexation. © 1998 Elsevier Science S.A. All rights reserved. |
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