Systematic interpretation of the anion-exchange behaviour of polyphosphateoligomers

Anion-exchange distribution ratio of some linear and cyclo-polyphosphate ol igomers were measured in tetramethylammonium chloride solution using Dowex 1-X4 anion-exchange resin. The selectivity coefficient K-Cl(p), of the exch ange reaction was evaluated from the log D vs, log([Cl-]/<([Cl-])over bar>) plot for each polyphosphate anion. The dependence of selectivity coefficie nt on the charge of the anion is interpreted in terms of the structure of t he phosphate species. Differences in selectivity coefficients between the l inear and cyclo-polyphosphate series are also discussed. (C) 1998 Elsevier Science B.V. All rights reserved.