Hydrolyses in pH 9.4–11.6 aqueous solutions containing 20% (v/v) acetonitrile were monitored by UV. First-order rate constants, k obs , were determined from plots of ln(A t –A ∞ ) vs. time. Second-order rate constants, k HO − , were determined from plots of k obs vs. [HO − ]. Products were identified and quantified by HPLC: Merck LiChrospher RP-8 5μm column; 15% acetonitrile - aqueous 5×10 −3 M Bu 4 NH 2 PO 4 (pH 5.90) eluant; retention times at a flow rate of ...
