61009-70-9Relevant academic research and scientific papers
Kinetic and Equilibrium Solvent Isotope Effects on the Deprotonation of a Salicylate Ion by Hydroxide Ion and General Bases
Hibbert, Frank
, p. 1304 - 1308 (2007/10/02)
Kinetic and equilibrium solvent isotope effects has been measured for proton transfer from 4-(3-nitrophenylazo)-salicylate ion (HA) to general bases (B) to examine whether a primary kinetic isotope effect is observed when proton transfer is occurring between bases of roughly equal strength for which ΔpK = pKHA - pKBH(1+) = 0.The kinetic solvent isotope effects for catalysis by three tertiary amines (ΔpK -0.85, -0.27, and +0.28) are kBH2O/kBD2O 2.0 +/-0.3, and 1.7 +/-0.2.Since for proton transfer to hydroxide ion (ΔpK -5.0) the isotope effect has a value kOH(1-)H2O(1-)/kOD(1-)D2O of 1.5 +/-0.1, the primary isotope effect for these proton transfers must be small and independent of base strength over the range studied.An explanation in terms of the reaction mechanisms is given.
