Kinetics, alkali metal cation facilitated

Acyclic oligoamides, 167-168,170/ Advancing front model, description, 116 Alkali metal cation facilitated transport through supported liquid membranes with fatty acids electrogenic processes, 79-81 electroneutral transport, 76-80 experimental description, 77 kinetics, 81-85... 

Yuan and Shao investigated the kinetics of several alkali metal ion transfers facilitated by DB18C6 at the water/DCE nano-interfaces. Their measurements yielded the rate constant for potassium transfer similar to that reported in ref. 13. Well shaped steady-state voltammograms were also obtained for other alkali metal cations, but the kinetic parameters determined for Li+, Rb and Cs+ showed significant correlation with the pipet radius. A similar approach was used by the same group to measure the kinetics of alkali metal transfers across the water/DCE interface facilitated with A-(2-tosylamino)-isopentyl-monoaza-15-crown-5. The association constants were measured for alkali metal complexes in DCE, and the selectivity of this ionophore was shown to follow the sequence... 

In 1982, Samec et al. studied the kinetics of assisted alkali and alkali-earth metal cation-transfer reactions by neutral carrier and conclnded that the kinetics of transfer of the monovalent ions were too fast to be measured [186]. In 1986, Kakutani et al. published a study of the kinetics of sodium transfer facilitated by di-benzo-18-crown-6 using ac-polarography [187]. They concluded that the transfer mechanism was a TIC process and that the rate constant was also high. Since then, kinetic studies of assisted-ion-transfer reactions have been mainly carried out at micro-lTlES. In 1995, Beattie et al. showed by impedance measurements that facilitated ion-transfer (FIT) reactions are somehow faster than the nonassisted ones [188,189]. In 1997, Shao and Mirkin used nanopipette voltammetry to measure the rate constant of the transfer of K+ assisted by the presence of di-benzo-18-crown-6, and standard rate constant values of the order of 1 cm-S were obtained [190]. A more systematic study was then published that showed the following sequence,, which is not in accordance with... 

---