Mechanism of the Transfer of Alkali- and Alkaline-Earth-Metal Ions across the Nitrobenzene-Water Interface Facilitated by Hexa- and Octaethylene Glycol Dodecyl Ethers

✍ Scribed by Takashi Kakiuchi

• Publisher: Elsevier Science
• Year: 1993
• Tongue: English
• Weight: 383 KB
• Volume: 156
• Category: Article
• ISSN: 0021-9797
• DOI: 10.1006/jcis.1993.1130

✦ Synopsis

Transfer of (\mathrm{Li}^{+}, \mathrm{Na}^{+}, \mathrm{K}^{+}, \mathrm{Rb}^{+}, \mathrm{Ca}^{2+}, \mathrm{Sr}^{2+}), and (\mathrm{Ba}^{2+}) ions facilitated by hexa- and octacthylene glycol monododecyl ethers (C12E6 and C12E8) has been studied at the nitrobenzene (NB)water (W) interface using cyclic voltammetry. When the concentration of C12En ( (n=6) or 8 ) in NB is higher than (1 \mathrm{mM}), cyclic voltammograms for all these ions show reversible transfer of ions facilitated by C12En. The current is mainly carried by 1:1 (metal:ligand) complex and is limited by the diffusion of C12En in NB. When the concentration of C12En in NB is lowered to the submillimolar range, the contribution of the adsorption of (\mathrm{C} 12 \mathrm{E} \boldsymbol{n}) to the current becomes significant. In the transfer of hydrophilic ions, e.g., (\mathrm{Li}^{+})and (\mathrm{Ca}^{2+}), the contribution of the complex with 1:2 (metal:ligand) stoichiometry to the measured current becomes nonnegligible. This 1:2 complex formation becomes pronounced with increasing ligand concentration. 1993 Academic Press. Inc.