caa a22 4500 445327391 CHVBK 20180317142725.0 cr unu---uuuuu 170323e20110101xx s 000 0 eng 10.1007/s10953-010-9625-7 doi (NATIONALLICENCE)springer-10.1007/s10953-010-9625-7 133Cs NMR Study of Cs+ Ion Complexes withAza-18-crown-6, Diaza-18-crown-6 andDibenzyldiaza-18-crown-6 in Binary Acetonitrile-Nitromethane Mixtures [Elektronische Daten] [Mojtaba Shamsipur, Nastaran Gilani, Mohammad Rofouei] Cesium-133 nuclear magnetic resonance spectroscopy was used as a sensitive probe to investigate the stoichiometry and stability of Cs+ ion complexes with aza-18-crown-6 (A18C6), diaza-18-crown-6 (DA18C6) and dibenzylediaza-18-crown-6 (DBzDA18C6) in different binary acetonitrile-nitromethane mixtures. In all cases, the exchange between free and complexed cesium ion was fast on the NMR time scale and only a single population average resonance was observed. The 133Cs chemical shift-mole ratio data indicated that the cesium ion forms 1:1 cation-ligand complexes with the investigated aza-crowns in all acetonitrile-nitromethane mixtures. The formation constants of the resulting complexes were evaluated from computer fitting of the chemical shift-mole ratio data. The stability of the resulting 1:1 complexes with Cs+ were found to vary in the order A18C6 > DBzDA18C6 > DA18C6. In all cases, there is the inverse relationship between the complex stability constants and the amount of acetonitrile in the mixed solvent. Springer Science+Business Media, LLC, 2010 Azacrowns nationallicence Cs+ ion nationallicence Mixed solvent nationallicence 133Cs NMR nationallicence Complex stability nationallicence Shamsipur Mojtaba Department of Chemistry, Razi University, Kermanshah, Iran aut Gilani Nastaran Teacher Training University, Tehran, Iran aut Rofouei Mohammad Teacher Training University, Tehran, Iran aut Journal of Solution Chemistry Springer US; http://www.springer-ny.com 40/1(2011-01-01), 40-47 0095-9782 40:1<40 2011 40 10953 https://doi.org/10.1007/s10953-010-9625-7 text/html Onlinezugriff via DOI 1 research-article jats NATIONALLICENCE 856 40 https://doi.org/10.1007/s10953-010-9625-7 text/html Onlinezugriff via DOI NATIONALLICENCE 700 1- Shamsipur Mojtaba Department of Chemistry, Razi University, Kermanshah, Iran aut NATIONALLICENCE 700 1- Gilani Nastaran Teacher Training University, Tehran, Iran aut NATIONALLICENCE 700 1- Rofouei Mohammad Teacher Training University, Tehran, Iran aut NATIONALLICENCE 773 0- Journal of Solution Chemistry Springer US; http://www.springer-ny.com 40/1(2011-01-01), 40-47 0095-9782 40:1<40 2011 40 10953 Metadata rights reserved Springer special CC-BY-NC licence nationallicence BK010053 XK010053 XK010000 NATIONALLICENCE NATIONALLICENCE NL-springer