Solubility Parameters and Solubilities of Metal Dithiocarbamates in Supercritical Carbon Dioxide

Abstract
The solubilities of Cu, Hg, and Zn complexes with seven different dithiocarbamate ligands in supercritical fluid CO2 at 60 °C and two pressures (100 and 230 atm) are reported. In each metal chelate system, the solubility of the metal−dithiocarbamate complex shows a strong correlation with the solubility parameters of the ligands, calculated using a group contribution method. Dithiocarbamate ligands with smaller solubility parameter values form metal complexes with higher solubilities in supercritical CO2. The solubility parameter value may provide a general guideline for selecting effective ligands for metal extraction in supercritical CO2.