Conductometric determination of the stability constants of the inclusion complexes of alkali cations with [22-DD] diaza crown ether, [211] and [221] cryptands in acetonitrile

Khalid M. Tawarah, Mohammad A. Khasawneh, Shehadeh A. Mizyed

Research output: Contribution to journalArticlepeer-review

8 Citations (Scopus)

Abstract

An equilibrium study concerning the association of Na+, K +, Rb+ and Cs+ with 4, 7, 13, 18-tetraoxa-1,10-diazabicyclo [8, 5, 5]-eicosane [211], 4, 7, 13, 16, 21-pentaoxa-1, 10-diazabicyclo [8, 8, 5]-tricosane [221] and 4, 13-didecyl-1, 7, 10, 16-tetraoxa-4, 13-diazacyclooctadecane [22-DD] in acetonitrile has been carried out at 25°C by using a conductometric technique. The observed molar conductivity, Λ, of a test solution was found to decrease significantly for mole ratios less than 1:1 upon the addition of the complexing ligand. A model based on 1:1 stoichiometry has been used to analyze the conductivity data. The data have been fitted according to a non-linear least-squares analysis that provides the stability constant, K, and the molar conductivity, Λc, for each cation - ligand inclusion complex. The binding sequences were found to follow the order: Na+ > K+ > Rb+ ≫ Cs+ (K ≈ 0) for [211], Na+ > K+ > Rb+ > Cs+ for [221] and K + > Na+ > Rb+ > Cs+ for [22-DD] complexes. Trends in ionic conductivities of complexed ions are also discussed.

Original languageEnglish
Pages (from-to)143-148
Number of pages6
JournalJournal of Inclusion Phenomena
Volume51
Issue number3-4
DOIs
Publication statusPublished - Apr 2005
Externally publishedYes

Keywords

  • Alkali metal cations
  • Azacrown ethers
  • Conductivity
  • Cryptands
  • Macrocyclic compounds
  • Stability constants

ASJC Scopus subject areas

  • Food Science
  • Chemistry(all)
  • Condensed Matter Physics

Fingerprint

Dive into the research topics of 'Conductometric determination of the stability constants of the inclusion complexes of alkali cations with [22-DD] diaza crown ether, [211] and [221] cryptands in acetonitrile'. Together they form a unique fingerprint.

Cite this