Abstract
Abstract Enthalpy and entropy changes for ion-pair extractions of tetraalkylammonium ions (Me4N+, Et4N+, n-Pr4N+, n-Bu4N+) with picrate anions, overall extractions of alkali metal (Na, K, Rb, Cs) picrates with 18-crown-6 (18C6), and distribution of 18C6 itself were determined between benzene and water, Me, Et, n-Pr, and n-Bu denoting methyl, ethyl, propyl, and butyl groups, respectively. All the extracted 18C6 complexes were 1:1:1 complexes (alkali metal ion: 18C6: picrate anion). The values of enthalpy and entropy changes are negative for overall extractions of all the alkali metal picrates with 18C6. Plots of thermodynamic quantities for ion-pair extractions of R4NA vs. the number of carbon atoms of R4N+ show a linear relationship, R4N+ and A− being tetraalkylammonium ion and picrate anion, respectively. Enthalpy and entropy changes were calculated for ion-pair extractions of 18C6–alkali metal ion complexes with picrate anions. The thermodynamic parameters for ion-pair extractions of 18C6–alkali metal picrate complexes were compared with those of R4NA, and were discussed in detail from the standpoint of molecular grounds. It was found from these data that the 18C6–K+ complex acts as a structure breaker in water.
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
