Prodigious Azocalix[4] Pyrrole Super-molecule: Effective Reagent for Liquid-liquid Extraction, Preconcentration and Transport of Cu(II) Ions

A novel series of eight prodigious calix[4]pyrrole super-molecules bearing azo-moiety at the meso position of the macrocycle have demonstrated the ability for liquid-liquid extraction, preconcentration and transport of Cu(II) ions across a liquid membrane. Various significant extraction parameters such as effect of pH, effect of solvent and effect of reagent concentration were investigated which showed high affinity and selectivity towards Cu(II) in the presence of large quantities of associated metal ions. The wavelengths of maximum extraction (λ max) and molar absorptivity (ε) have also been determined. The stoichiometry of complex was evaluated by slope ratio method. The system obeys Beer’s law over the range 0.5–10.0 μg mL-1. Liquid membrane transport studies of Cu(II) were carried out from source to the receiving phase under controlled conditions and a mechanism of transport is proposed. To check the validity of the proposed method, Cu(II) was analyzed in natural and ground water samples of Ahmedabad city, Gujarat, India.