Solubility of chelating agents and metal-containing compounds in supercritical fluid carbon dioxide

The solubility of 49 metal-containing compounds and 15 "free" ligands in supercritical fluid carbon dioxide is reviewed. Solubilities were found to range over eight orders of magnitude, with the highest value of solubility being 56 g l(-1). Metals complexed with fluorine substituted ligands were found to be the most soluble, and metals complexed with phenyl-substituted ligands the least soluble. A general trend for increasing solubility with increasing oxidation state is observed and this is correlated with the increased number of coordinating ligands protecting the metal center from interaction with the supercritical fluid and also due to the increased number of solvation interactions with the increased number of ligand groups.