Crown ether ionophores

As stated in Section II, the SHG responses to primary cations of ISEs based on several crown ether ionophores could be correlated to the number of primary ion complexes at the phase boundary, which contributed to the membrane potential. We have now incorporated the K+ ionophore bis[(benzo-15-crown-5)-4-methyl]pimelate into 1,2-dichloroethane and nitrobenzene membranes and determined EMF and SHG responses to KCl in presence and absence of ionic sites. 

Based on an optrode previously reported by Simon et al. for the determination of 1-phenylethylammonium ion using a crown ether ionophore... 

Other crown ether ionophores have been developed as ion sensors. The first reports of crown ethers as dyes appeared in the 1970s. These derivatives of benzo-15-crown-5 undergo a color change when bound to specific ions and can be used as efficient extractors for ions from aqueous solution. Numerous other chromoionophores have also been prepared and were reviewed by Takagi (1984). 

Solid models for these liquid/liquid interfaces in which one of the solutions is replaced by a polymer, often swollen with a significant proportion of solvent, have proved useful in SHG studies of analytically relevant studies of liquid/liquid junctions, for example, the study of crown ether ionophores imbedded in a PVC film. 

Horvath, V. Takacs, T. Horvai, G. Huszthy, P. Bradshaw, J. S. Izatt, R. M., Enantiomer-selectivity of ion-selective electrodes based on a chiral crown-ether ionophore, Anal. Lett. 1997,30,1591-1609... 

The first electrochemical observation of a facilitated ion transfer reaction was reported in 1979 by Koryta et al They studied the transfer of potassium from water to nitrobenzene, facilitated by the crown ether ionophore dibenzo-18-crown-6. This original publication has heralded an important part of the field of electrochemistry at liquid-liquid interfaces. The Prague group at the Heyrovsky Institute dedicated a lot of attention to this particular subject, resulting in a large number of publications. The ionophores investigated included nonactin, monensin, calcium ionophore, dibenzo-18-crown-6, tetracycline, valinomycin, and nigericin. ... 

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