
%0 Journal Article
%A Kean, Suzanna D. 
%A May, Bruce L. 
%A Clements, Philip 
%A Easton, Christopher J. 
%A Lincoln, Stephen F. 
%T Host-Guest Complexation of Aromatic Carboxylic Acids and their Conjugate Bases by &#946;-Cyclodextrins Monosubstituted at C 6 by Linear and Cyclic Alkyl Triamines in Aqueous Solution
%J Australian Journal of Chemistry
%D 2000/03/14
%V 52
%N 12
%P 1157-1163
%K 
%R https://doi.org/10.1071/CH99100
%U https://www.publish.csiro.au/paper/CH99100 
%X A pH titrimetric study of the complexation of the guests benzoic acid, 4-methylbenzoic acid and (R)- and (S)-2-phenylpropanoic acids and their conjugate bases by the host 6A-&#91;2-(2-aminoethylamino)ethylamino&#93;-, 6A-&#91;3-(3-aminopropylamino)propylamino&#93;-, 6A-(1,4,7-triazacyclononan-1-yl)-, and 6A-(1,5,9-triazacyclododecan-1-yl)-6A-deoxy-&#946;-cyclodextrins (&#946;CDdien, &#946;CDdipn, &#946;CDtacn and &#946;CDtacdo, respectively) is reported. Over the pH range 3.0&#8211;11.0, 49 host&#8211;guest complexes were detected. Their stability constants (K) range from 220&#177;50 dm3 mol&#8211;1 for the &#946;CDdienH22+ &#183;benzoate&#8211; complex to 48000&#177;11000 dm3 mol&#8211;1 for the &#946;CDdipnH22+&#183;(S)-2-phenylpropanoic acid complex at 298.2 K and I = 0.10 mol dm&#8211;3 (NaClO4). The latter K value is among the highest reported for a complex of a simple carboxylic acid with a substituted &#946;-cyclodextrin. The charge, hydrophobicity and stereochemistry of both host and guest appear to be significant factors in the variation of host&#8211;guest complex stability. 1H ROESY n.m.r. studies of some of the complexes formed are also reported. 
