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A new 1,3-diderivative of calix[4]arene appended with hydroxymethyl salicylyl imine is prepared and its ion recognition toward biologically relevant [M.sup.n+] ions is analyzed. The studies have shown that while [H.sub.2]L is selective for [Zn.sup.2+] among a number of cations, the [ZnL] is selective toward phosphate among a number of anions and also toward Asp, Cys and His among the naturally occurring amino acids.

A structurally characterized lower rim 1,3-di{bis(2-picolyl)}amide derivative of calix[4]arene (L) has displayed high selectivity toward [Ag.sup.+] by forming a 1:1 complex, among nine other biologically important metal ions. The in situ prepared silver complex of L has detected Cys ratiometrically among the amino acids to a lowest concentration by releasing L from the complex followed by formation of the cysteine complex of [Ag.sup.+] and the INH logic gate is generated by choosing [Ag.sup.+] and Cys as input.

Several experimental and computational studies are conducted to explain the selective recognition of [Hg.sup.2-] ion exhibited by the amide linked lower rim 1,3-dibenzimidazole derivative of calix[4]arene. The solvent and benzimidazole moieties are shown to play an extremely significant role in the discussed phenomenon.