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Nucleophilic Substitution in Dipolar Aprotic Solvents: Hexamethylphosphoric triamide
Author(s) -
Müller Paul,
Siegfried Bernard
Publication year - 1972
Publication title -
helvetica chimica acta
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.74
H-Index - 82
eISSN - 1522-2675
pISSN - 0018-019X
DOI - 10.1002/hlca.19720550829
Subject(s) - chemistry , bromide , mole , nucleophilic substitution , medicinal chemistry , reaction rate constant , ion , chloride , inorganic chemistry , counterion , dissociation (chemistry) , equilibrium constant , dissociation constant , organic chemistry , kinetics , physics , biochemistry , receptor , quantum mechanics
The rate of the reaction between ethyl tosylate and chloride as well as bromide ion has been measured in hexamethylphosphoric triamide in the presence of several counterions. Rate constants for the free ions at 25.0° are 14.4 mole −1 for chloride and 2.0 mole −1 min −1 for bromide, both independent of the cation used. The equilibrium constants for ion pair dissociation of lithium‐, ammonium‐ and tetra‐ n ‐butylammonium chloride are 3.97 × 10 −2 , 1.52 × 10 −3 and 6.36 × 10 −3 mole, and for the corresponding bromides 3.30 × 10 −2 , 9.65 × 10 −3 , and 9.62 × 10 −3 mole.