Thermodynamic study of the complexation of p-isopropylcalix[6]arene with Cs+ cation in dimethylsulfoxide-acetonitrile binary media

Molecules. 2011 Sep 22;16(9):8130-42. doi: 10.3390/molecules16098130.

Abstract

The complexation reactions between the macrocyclic ionophore, p-isopropylcalix[6]arene and Cs+ cation were studied in dimethylsulfoxide-acetonitrile (DMSO-AN) binary non-aqueous solvents at different temperatures using a conductometry method. The conductance data show that the stoichiometry of the (p-isopropylcalix[6]-arene·Cs)+ complex in all binary mixed solvents is 1:1. The stability of the complexes is affected by the composition of the binary solvent media and a non-linear behavior was observed for changes of log K(f) of the complex versus the composition of the binary mixed solvents. The thermodynamic parameters (DH°(c) and DS°(c)) for formation of (p-isopropyl-calix[6]arene·Cs)+ complex were obtained from temperature dependence of the stability constant and the obtained results show that the (p-isopropylcalix[6]arene·Cs)+ complex is enthalpy destabilized, but entropy stabilized, and the values of the mentioned parameters are affected strongly by the nature and composition of the binary mixed solvents.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Acetonitriles / chemistry*
  • Calixarenes / chemistry*
  • Cations
  • Cesium / chemistry*
  • Chelating Agents / chemistry*
  • Chlorides / chemistry*
  • Conductometry
  • Coordination Complexes / chemistry*
  • Dimethyl Sulfoxide / chemistry*
  • Solvents
  • Thermodynamics

Substances

  • Acetonitriles
  • Cations
  • Chelating Agents
  • Chlorides
  • Coordination Complexes
  • Solvents
  • Calixarenes
  • Cesium
  • cesium chloride
  • Dimethyl Sulfoxide
  • acetonitrile