RESUMO
CO(2)-binding organic liquids (CO(2)BOLs) are mixtures of a base (typically an amidine or guanidine) and an alcohol, and have been shown to reversibly capture and release CO(2) with low reaction energies and high gravimetric CO(2) capacity. We now report the ability of such liquid blends to chemically bind and release other acid gases such as CS(2), COS, and SO(2) analogously to CO(2). These systems bind with sulfur-containing acid gases to form colored ionic liquids with new O-alkylxanthate, O-alkylthiocarbonyl, and O-alkylsulfite anions. The capture and thermal stripping of each acid gas from these systems and their applicability towards flue gas desulfurization is discussed.
RESUMO
The keto-enol equilibria of the beta-diketones acetylacetone, trifluoroacetylacetone, and hexafluoroacetylacetone were determined using Fourier transform infrared spectroscopy in a novel high-pressure capillary cell. Acetylacetone and its fluorinated analogues were studied as neat liquid and as supercritical CO2 solutions at pressures up to 3.1 kbar. The keto form was found to be favored at high pressure and low temperature. The change in partial molar volume and enthalpy between the keto and enol forms was determined for the acetylacetone and trifluoroacetylacetone. Under all conditions studied, only the enol form of hexafluoroacetylacetone was observed. Based on the thermodynamic data obtained, there appears to be no advantage gained in conducting metal extractions at high pressures and low temperatures using acetylacetone or trifluoroacetylacetone.
RESUMO
Feasible photocatalysis: The rhodium catalyst [Rh(CO)(PMe3 )2 Cl] photochemically transforms ethane to propionaldehyde in single-phase mixtures of ethane and in carbon dioxide/ethane single phases [Eq. (1)]. A side reaction of carbon dioxide with the catalyst to give OPMe3 and [Rh(CO)2 (PMe3 )Cl] or [Rh2 (CO)2 (PMe3 )2 (µ-Cl)2 ] has also been observed.
