The hydrolysis reactions of three (2-deoxy-beta-D-glucopyranosyl)pyridinium salts exhibit first-order rate constants that are independent of pH in the range of 4.4-10.1 pH units. Derived second-order rate constants for the hydrolysis reactions of (2-deoxy-beta-D-glucopyranosyl-4’-bromoisoquinolinium bromide (5b) conducted in the presence of nucleophilic monoanions (mu 2.0) including AcO-, Cl-, Br-, and N-3(-) exhibit a Swain-Scott parameter (s) of 0.03 +/- 0.05, indicating that these reactions show no sensitivity to the nature of the anion. However, a substantial quantity of the (2-deoxyglucopyranosyl)pyridinium salt hydrolysis product is formed as a result of a post-rate-limiting reaction involving a nucleophilic anion. Analysis of the product ratios indicates that the first-formed intermediate in the hydrolytic reaction is a solvent-separated ion pair:molecule encounter complex. The data allow a calculated estimate of greater than 2.5 x 10(-12) s for the lifetime of the glucopyranosyloxocarbenium ion in aqueous solution,