Equilibrium Constants of the Complexation of Molybdate Ion with para-Sulfonatocalix [4] arene in aqueous media

The complexation of sodium molybdate with para-sulfonatocalix [4] arene was studied in thetemperature range from 20 to 40 °C and pH = 5.8 by spectroscopic method in water solution. Thestability constants of complexes were calculated by the multiwavelength analysis of spectral datausing SQUAD program. The equilibrium constant, spectroscopic data, molar absorptivities andconcentrations of all species were adequately optimized by program when the chemical modelwith 1:1 stoichiometry was considered in the calculation. The extracted values of molarabsorptivities and concentration- profile of the formed complex were reported. The logarithms ofthe stability constants of complexes were calculated to be 3.672, 3.143, 2.986, 2.555, and 2.333at20, 25, 30, 35and 40 °C respectively