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Kinetics and Mechanism for the Reaction of Hexafluoroacetylacetone with CuO in Supercritical Carbon Dioxide

“…A similar effect was reported in the extraction of both stainless steel and trivalent lanthanide ions with β-diketones and water in scCO 2 . In the case of stainless steel, the catalytic effect leveled off at a water concentration of approximately 2.7 times the molar amount of hfacH . Interestingly, low concentrations of water have also proven beneficial for Cu deposition from metal chelate complexes .…”

“…For example, the addition of small amounts of water increased scandium metal solubility in neat liquid hfacH as well as various other metals in several β-diketones . A similar effect was reported in the extraction of both stainless steel and trivalent lanthanide ions with β-diketones and water in scCO 2 . In the case of stainless steel, the catalytic effect leveled off at a water concentration of approximately 2.7 times the molar amount of hfacH .…”

“…Much of the research on heterogeneous metal chelation chemistry has focused on reactions in the gas phase, but recently we and others have reported that metals can be etched using β-diketone chelators dissolved in supercritical carbon dioxide (scCO 2 ). − Interest in scCO 2 technology has surged over the past 10 years due in large part to increasing environmental awareness for alternative solvents. In contrast with most organic solvents that have to be treated and disposed of as hazardous waste, carbon dioxide is nontoxic and nonflammable and can be cleanly separated and removed from a system by depressurization.…”

Hollow Microcrystals of Copper Hexafluoroacetylacetonate-Pyridine Derivative Adducts via Supercritical CO2 Recrystallization

“…Reports on the use of scCO 2 as a solvent for the synthesis of coordination compounds are very scarce . Previous studies have described the use of scCO 2 to process [Cu­(hfacac) 2 ], either to deposit copper films, , to produce copper particles, to obtain one-dimensional coordination polymers, or for the etching of copper using hfacac in scCO 2 . , In the etching conditions, a [Cu­(hfacac) 2 ­(Py) 2 ] adduct was probably formed, although the authors did not report its isolation or characterization.…”

Nanoporous Silver with Controllable Optical Properties Formed by Chemical Dealloying in Supercritical CO2

“…This work extends supercritical fluid etching of a single component metal to a multicomponent system and demonstrates dealloying of multiphase AgCu. Previous studies showed that by either sequential or simultaneous oxidation and chelation, blanket copper metal films and islands were etched in scCO 2 . − The heterogeneous reaction of positively charged Cu atoms with chelators produced complexes that were soluble in the nonpolar, neutral fluid. Silver is inherently more resistant to oxidation than Cu and under most conditions, a AgCu alloy will form an oxide scale consisting of CuO and metallic Ag .…”