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Kinetic Study of the Isotope Exchange Reactions of Malonic Acid and Malonate Ion Using 1 H NMR Spectroscopy. Inhibition of Acid and Base
Author(s) -
Hsu MingChing,
Jwo JingJer
Publication year - 1999
Publication title -
journal of the chinese chemical society
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.329
H-Index - 45
eISSN - 2192-6549
pISSN - 0009-4536
DOI - 10.1002/jccs.199900023
Subject(s) - chemistry , malonic acid , malonate , kinetic isotope effect , ion exchange , medicinal chemistry , inorganic chemistry , reaction mechanism , acetic acid , catalysis , ion , organic chemistry , deuterium , physics , quantum mechanics
The isotope exchange reactions of malonic acid and a malonate ion were investigated in acidic and basic D 2 O solutions, respectively, using 1 H NMR spectroscopy. The isotope exchange reaction of malonic acid is inhibited by the presence of DNO 3 (0–3 M) and DSO 4 − ion (0–0.1 M), whereas it is catalyzed by the presence of DSO 4 − ion (> 0.2 M), D 3 PO 4 , D 2 PO 4 − ion or DPO 4 2– ion. The order of relative reactivity for catalyzing the isotope reaction of malonic acid in D 2 O is DPO 4 2– > D 2 PO 4 − > D 3 PO 4 > DSO 4 − > DNO 3 . The rate of the isotope exchange reaction of malonate ion in D 2 O decreases to a minimum and then increases with increased [NaOD] 0 . The mechanism of the isotope exchange reaction of malonic acid in acidic D 2 O is different from the general acid‐catalyzed mechanism generally observed for organic acids like acetic and dichloroacetic acids. The bimalonate ion plays an important role in the isotope exchange reactions of this system.