
%0 Journal Article
%A Dhillon, R 
%A Easton, CJ 
%A Lincoln, SF 
%A Papageorgiou, J 
%T Complexation of Benzoic, 4-Methylbenzoic, and (R)- and (S)-2-Phenylpropanoic Acids and Their Conjugate Bases by 3<sup>A</sup>-Amino-3<sup>A</sup>-deoxy-(2<sup>A</sup>S,3<sup>A</sup>S)-&#946;-cyclodextrin in Aqueous Solution
%J Australian Journal of Chemistry
%D 1995/06/01
%V 48
%N 6
%P 1117-1124
%K 
%R https://doi.org/10.1071/CH9951117
%U https://www.publish.csiro.au/paper/CH9951117 
%X A potentiometric titration study of the complexation of benzoic, 4-methylbenzoic, and (R)- and (S)-2-phenylpropanoic acids and their conjugate bases by 3A-amino-3A-deoxy-(2AS,3AS)-&#946;- cyclodextrin, &#946;CD3NH2, in which the amino group may be protonated to produce a singly charged species, &#946;CD3NH3+, is reported. In aqueous solution at 298.2K and I = 0.10 mol dm-3 ( KCl ), the complexation constants for the complexes indicated have the values (in dm3 mol-1) shown in parentheses: benzoic acid.&#946;CD3NH3+ (KHA = 110±10); benzoate.&#946;CD3NH3+ (KA = 19±2); 4-methylbenzoic acid.&#946;CD3NH3+ (KHA = 210±10); 4-methylbenzoate.&#946;CD3NH3+ (KA = 21±3); (R)- and (S)-2-phenylpropanoic acid.&#946;CD3NH3+ (KRHA = 64±8, KSHA = 57±5); (R)- and (S)-2-phenylpropanoate.&#946;CD3NH3+ (KRA = 51±6, KSA = 32±6); and (R)- and (S)-2-phenylpropanoate.&#946;CD3NH2 (KRA&#8242; = 13±7; KSA&#8242; is too small to quantify reliably). These complexation constants are substantially less than those for the host-guest complexes formed by the isomeric 6A-amino-6A-deoxy-&#946;-cyclodextrin and also for those formed by &#946;-cyclodextrin. The origins of these differences are discussed. 
