DETERMINATION OF THE COMPLEXATION CONSTANTS BETWEEN ALKYLPYRIDINIUM BROMIDE AND ALPHA-CYCLODEXTRIN AND BETA-CYCLODEXTRIN USING ELECTROMOTIVE-FORCE METHODS
H. Mwakibete et al., DETERMINATION OF THE COMPLEXATION CONSTANTS BETWEEN ALKYLPYRIDINIUM BROMIDE AND ALPHA-CYCLODEXTRIN AND BETA-CYCLODEXTRIN USING ELECTROMOTIVE-FORCE METHODS, Langmuir, 10(9), 1994, pp. 3328-3331
Electrochemical studies using surfactant membrane selective electrodes
have shown that both alpha- and beta-cyclodextrins form 1:1 inclusion
compounds with alkylpyridinium bromides (C(n)PyBr, n = 10, 12, 14, 16
). For each surfactant in this homologous series the complexation cons
tant involving alpha-cyclodextrin is always higher than the value for
the corresponding beta-cyclodextrin. In addition for both cyclodextrin
s the complexation constants increase as the chain length of the surfa
ctant increases, showing that the driving force dominating the formati
on of these complexes is the hydrophobic effect. However, it is though
t that the formation of 1:2 surfactant-cyclodextrin complexes are prev
ented by the repulsive forces between the complexed cyclodextrin and t
he surfactant head group.