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Matrix influence on stability constants of 15-crown-5-alkali metal complexes measured by liquid secondary ion mass spectrometry

✍ Scribed by Denis Giraud; Olivier Laprévote; Bhupesh C. Das


Publisher
John Wiley and Sons
Year
1994
Tongue
English
Weight
550 KB
Volume
29
Category
Article
ISSN
1076-5174

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✦ Synopsis


The liquid secondary ion mass spectra of 15-crown-5 in the presence of equimolecular mixtures of three alkali metal salts show large changes in the relative abundances of the 15-crown-5-cation complexes formed, depending on the relative concentrations of ligand and salts. These variations are due either to various desorption rates of the cationized species or to different affinities of 15-crown-5 toward the alkali metal cations. An original method allowing discrimination between desorption and complexation effects on the relative abundance of ligand-metal complex ions is described and can be applied for the calculation of their stability constants. The spectral data obtained using two different matrices demonstrate that the matrix polarity has a very important effect on the two parameters considered, i.e. the stability constants of the 15-crown-5<ation complexes and their desorption rates.