
TY  - JOUR
A1  - Sandow, Melissa 
A1  - May, Bruce L. 
A1  - Easton, Christopher J. 
A1  - Lincoln, Stephen F. 
T1  - Binary and Ternary Metallo-&#946;-cyclodextrins of 6<emph type="7">A</emph>-[Bis(carboxylatomethyl)amino]-6<emph type="7">A</emph>-deoxy-&#946;-cyclodextrin
JF  - Australian Journal of Chemistry
JO  - Aust. J. Chem.
Y1  - 2000
VL  - 53
IS  - 2
SP  - 149
EP  - 152
KW  - Cyclodextrin; host&#8211;guest complex; imidodiacetate; complexation.
UR  - https://doi.org/10.1071/CH00001 
N2  - The binary metallo-&#946;-cyclodextrins formed by 6A-&#91;bis(carboxylatomethyl)amino&#93;-6A-deoxy-&#946;-cyclodextrin (&#91;M(&#946;CDida)&#93;, where M2+ = Co2+, Ni2+, Cu2+ and Zn2+) are characterized by log(K/dm3 mol&#8211;1) = 7.29&#177;0.01, 9.74&#177; 0.02, 8.89&#177;0.03 and 6.08&#177;0.02, respectively, in aqueous solution at 298.2 K and I = 0.10 mol dm&#8211;3 (NaClO4), where K is the stability constant. The ternary metallo-&#946;-cyclodextrins formed by &#91;M(&#946;CDida)&#93; and (R)- and (S)-tryptophanate, &#91;M(&#946;CDida)(R)-Trp&#93; &#8211; and &#91;M(&#946;CDida)(S)-Trp&#93;&#8211; , are characterized by log(K/dm3 mol&#8211;1) = 5.49&#177;0.04 and 5.16&#177;0.07, 6.33&#177;0.04 and 6.34&#177;0.02, 6.91&#177;0.02 and 6.99&#177;0.01, and 5.34&#177;0.02 and 5.36&#177;0.04, respectively, when M2+ = Co2+, Ni2+, Cu2+ and Zn2+. For &#91;M(&#946;CDida)(R)-Trp&#93;&#8211; and &#91;M(&#946;CDida)(S)-Trp&#93;&#8211;, pKa values of 8.07&#177;0.04 and 8.4&#177;0.1, 7.45&#177;0.02 and 7.88&#177;0.04, 8.46&#177;0.09 and 8.40&#177;0.01, and 8.92&#177;0.05 and 8.7&#177;0.2 are found when M2+ = Co2+, Ni2+, Cu2+ and Zn2+, respectively, and are attributed to the protolysis of an aqua ligand occupying a sixth coordination site on M2+ . 
ER  -

