Synthesis and cation selectivity of 25, 27, dipropoxy-26, 28, Di-propoxy 5, 11, 17, 23, ptert-butyl Calix[4]arene are studied in acetonitrile solution. The stability constants of differentcomplexes of Calixarene (as a ligand) with alkali metal cations are determined at 25 °C by usingspectrophotometric technique.On the basis of calculations, complexation of Calixarene with Cs+and Li+ are more favored than others. In all cases, it has been shown to form exclusively 1:1(metal ion to ligand) complex with alkali cations in experimental condition. Manuscript profile