Abstract
Following an overview in the field of calixarene chemistry given in the introduction, this thesis reports, i) The synthesis of p-text-butylcalix[4]arene tetraacetamides, thiophosphates and derivatives containing mixed functional groups and the characterisation by IR, NMR and microanalysis. ii) The solution thermodynamic of p-tert-butylcalix[4]arene tetradiisopropylacetamide and the transfer thermodynamics of this ligand from acetonitrile to various solvents. iii) Spectrophotometric, potentiometric and calorimetric studies on the interaction of p-tert-butylcalix[4]arene tetraacetamides and metal cations in butan-l-ol and in water saturated butan-l-ol at 298.15 K. Metal-ion complexes of p-tert-butylcalix[4]arene tetradiisopropylacetamide were isolated and characterised by IR, NMR and spectroscopy and microanalysis. In butan-l-ol, the selectivity of this ligand for metal cations follows the sequence Na+ > Cd2+ > Pb2+ > Zn2+ > Ag+. However, this sequence is altered in the water saturated solvent to an extent that the strong complexation observed for this ligand and zinc(II) in butan-l-ol is non-existent in the water saturated solvent. Using complexation data in conjunction with solution data of the host, the guest and the resulting complex, enthalpies of coordination (referred to the process which reactants and the product in the solid state) were calculated. iv) Extraction experiments in the water-butan-l-ol solvent system at 298.15 K in the presence of p-tert-butylcalix[4]arene tetradiisopropylacetamide were performed. The higher extraction of lead(II) relative to other metal cations from the aqueous solution to the organic phase in the presence of the ligand at low hydrogen-ion concentration is demonstrated. The extraction of radioactive lead(II) by the same ligand was investigated as a function of i) the pH of the aqueous phase ii) the ligand concentration in the organic phase. vi) A new polymeric material was obtained by attaching the ligand to the polymer. Final conclusions are drawn and suggestions for further work in this area are given.