
TY  - JOUR
A1  - Whitbread, Sonya L. 
A1  - Weeks, Jennifer M. 
A1  - Valente, Peter 
A1  - Buntine, Mark A. 
A1  - Lincoln, Stephen F. 
A1  - Wainwright, Kevin P. 
T1  - Enantiomerization of Pendant-Arm Triaza Macrocyclic Lithium(I) and Sodium(I) Complex Ions
JF  - Australian Journal of Chemistry
JO  - Aust. J. Chem.
Y1  - 1997
VL  - 50
IS  - 8
SP  - 853
EP  - 856
KW  - 
UR  - https://doi.org/10.1071/C97068 
N2  - The first reported enantiomerization of six-coordinate alkali metal complex ions, represented by 1,4,7-tris(2-hydroxyethyl)-1,4,7-triazacyclononanelithium(I) and its sodium(I) analogue in methanol, has been characterized by variable-temperature 13C&#123;1H&#125; n.m.r. spectroscopy. The respective kinetic parameters are: k = (1&#183;11 &#177; 0&#183;05) &#215; 106 and (2&#183;27 &#177; 0&#183;09) &#215; 105 s-1 at 298&#183;2 K, &#916;H = 27&#183;2 &#177; 0&#183;3 and 21&#183;7&#177;0&#183;2 kJ mol-1, and &#916;S = &#8211;36&#183;3 &#177; 1&#183;3 and &#8211;69&#183;6&#177;1&#183;2 J K-1 mol-1. Molecular orbital calculations show that these enantiomers have distorted trigonal prismatic structures consistent with the interpretation of the n.m.r. spectra. For the Li+, Na+, K+, Rb+ and Cs+ complex ions log(K/dm3 mol&#8722;1) = 3&#183;13&#177;0&#183;09, 3&#183;52&#177;0&#183;05, 3&#183;23&#177;0&#183;05, 2&#183;78&#177;0&#183;10 and 2&#183;47&#177;0&#183;08, respectively, at 298&#183;2 K and I = 0&#183;05 mol dm-3 (NEt4 ClO4) in methanol, where K is the complex ion stability constant. 
ER  -

