Selectivity of membrane electrodes based on derivatives of dibenzyltin dichloride.
Selectivity properties are established for membrane electrodes prepared by incorporating bis(p-methylbenzyl)tin dichloride, dibenzyltin dichloride, and bis(p-chlorobenzyl)tin dichloride in plasticized polymer membranes. These electrodes display an unusually high level of selectivity for dibasic phosphate over many common anions. Electrodes prepared with the p-chloro derivative possess the best detection limit and the highest degree of selectivity for phosphate. Selectivity coefficients are calculated for phosphate relative to the following groups of anions: salicylate, benzoate, thiocyanate, iodide, nitrate, bromide, chloride, acetate, fluoride, pyrophosphate, arsenate, adenosine 5'-cyclic monophosphate, adenosine 5'-monophosphate, adenosine 5'-diphosphate, and adenosine 5'-triphosphate. Tin-carbon hyperconjugation within the organotin compound is hypothesized to be critically important in the selective response to phosphate. Enhancement of tin-carbon hyperconjugation by increasing the electron-withdrawing power of substituents on the benzyl ring is predicted to provide even higher levels of selectivity for phosphate.
Glazier
S A
SA
Department of Chemistry, University of Iowa, Iowa City 52242.
Arnold
M A
MA
D001593:Benzyl Compounds; D004566:Electrodes; D008567:Membranes, Artificial; D009947:Organotin Compounds
D001593:Benzyl Compounds; D008567:Membranes, Artificial; D009947:Organotin Compounds; C070404:bis(4-chlorobenzyl)tin dichloride; C070406:dibenzyltin dichloride; C070402:bis(4-methylbenzyl)tin dichloride