
TY  - JOUR
A1  - Wyness, Oska 
A1  - May, Bruce L. 
A1  - Clements, Philip 
A1  - Lincoln, Stephen F. 
A1  - Easton, Christopher J. 
T1  - Diazacoronand-Linked &#945;- and &#946;-Cyclodextrin Dimer  Complexes of the Brilliant Yellow Tetraanion
JF  - Australian Journal of Chemistry
JO  - Aust. J. Chem.
Y1  - 2004
VL  - 57
IS  - 6
SP  - 571
EP  - 576
KW  - 
UR  - https://doi.org/10.1071/CH03268 
N2  - Complexation of the Brilliant Yellow tetraanion, 14&#8211;, by the new coronand-linked &#945;- and &#946;-cyclodextrin (&#945;CD and &#946;CD) dimers 4,13-bis(6 A-deoxy-&#945;-cyclodextrin-6 A-ylamidomethyl)-4,13-diaza-1,7,10-trioxacyclodecapentane and 4,13-bis(6 A-deoxy-&#946;-cyclodextrin-6 A-ylamidomethyl)-4,13-diaza-1,7,10-trioxacyclodecapentane, 2 and 3, respectively, has been studied in aqueous solution. The complexation constants for 2 &#183; 14&#8211; and 3 &#183; 14&#8211; are K1 = (3.20 &#177; 0.05) &#215; 105 and (2.76 &#177; 0.09) &#215; 104 dm3 mol&#8211;1, respectively, at 298.2 K, pH 10.0, and I 0.10 mol dm&#8211;3 (NEt4ClO4). The pK a values of 2 &#183; H22+ are 6.57 &#177; 0.04 and 5.88 &#177; 0.05, and of 3 &#183; H22+ are 6.70 &#177; 0.03 and 6.08 &#177; 0.02. Complexation of the alkaline earth metal ions by 2 is characterized by complexation constants (2.73 &#177; 0.51) &#215; 102, (1.52 &#177; 0.36) &#215; 105, (1.49 &#177; 0.03) &#215; 105, and (4.28 &#177; 0.07) &#215; 104 dm3 mol&#8211;1 for Mg2+, Ca2+, Sr2+, and Ba2+, respectively. These data are compared with those reported for analogous coronand-linked &#946;CD dimer complexes to establish the hierarchy of the factors determining the stability of such complexes. 
ER  -

