Lower rim 1,3-bis(aminoethoxy)-p-t-butyl-calix[4]arene derivative (L) has been subjected to fluorescence and absorption studies to evaluate its utility to recognize halides. This derivative has been found to be selective towards iodide, immaterial of its counter cation as well as the presence of other halide ions. Combining this data with that of the negative ion mass spectrometry and 1H NMR spectra, an arene cavity bound iodide species is proposed.