Synthesis, IR and NMR characterization and ion extraction properties of tetranonylcalix[4]resorcinol bearing acetylhydrazone groups

A series of new calix[4]resorcinarenes (rccc-isomer) and resorcinols functionalized by acetylhydrazone binding fragments have been synthesized. The IR and NMR data and stereochemical behaviour of hydrazones are reported and compared with the results of earlier investigations. The barriers of rotation of hydrazone fragments for some octahydrazone derivatives of calix[4]resorcinarenes and their resorcinol analogues have been determined by NMR-measurements. The complexing behaviour of bis- and octahydrazones has been studied by liquid-liquid extraction towards the s-metal ions (Li+, Na+, K+, Cs+ and Ca2+), p-metal ions (Pb2+), d-metal ions (Co2+, Ni2+, Cu2+, Zn2+, Cd2+ and Hg2+) and f-metal ions (La3+, Gd3+ and Lu3+). The stoichiometry of complexes and the extraction constants have been determined. It has been established that octahydrazones do not extract alkali metal cations but show excellent selectivity towards transition and soft heavy metal cations (especially Hg2+ or Pb2+). (C) 2008 Elsevier Ltd. All rights reserved.