Decarboxylation of 6-nitrobenzisoxazole-3-carboxylate in polyampholyte latexes

Polyampholyte latexes that contain 29/18 and 25/23 mol % of (styrylmethyl)t rimethylammonium/methacrylate units and styrene cross-linked with divinylbe nzene are colloidally stable in 4 M NaCl solution. As catalytic media in ba sic solutions 0.5 mg mL(-1) of the polyampholyte latexes increase the rate of decarboxylation of 6-nitrobenzisoxazole-3-carboxylate (6-NBIC) 60-115 ti mes, while the precursor polycation latexes increase the rate 540-670 times the rate in water alone. The latexes are active catalysts in 0.67 M NaCl s olution, but activity decreases as the concentration of added NaCl increase s. Analysis of rate constants at varied particle concentrations indicates t hat the fractions of the 6-NBIC anions bound to particles are similar in th e two types of latexes and that the differences in activity are due primari ly to larger intraparticle rate constants in the polycation latexes than in the polyampholytes.