Cu2+ Selective Chromogenic Behavior of Calix[4]arene Derivative

This study involves the copper selective chromogenic response of 5, 11, 17, 23-Tetrakis (N-pyrrolidinomethyl)-25, 26, 27, 28-tetrahydroxycalix[4]arene based mannich base (3). Complexation ability of (3) was explored by examining the effect of a series of various metal ions, such as Li+, Na+, K+, Ag+, Ba2+, Ca2+, Mn2+, Mg2+, Sr2+, Ni2+, Cd2+, Co2+, Cu2+, Hg2+, Pb2+, Zn2+, Fe2+, Fe3+, and Al3+, by using UV-visible spectroscopy. Ligand (3) exhibited pronounced selectivity toward Cu2+ even in the presence of various co-existing ions. The stoichiometric analysis, i.e., Job's plot revealed that (3) form 1:1 complex with Cu2+ ion in DMF-H2O system. The complexation phenomenon was confirmed by FT-IR spectroscopy that favors the selective nature of (3) with Cu2+.