Carbon dioxide basic water illustrates this property, in which case hydroxide is the nucleophile. Other nucleophiles react as well. For example, carbanions as provided by Grignard reagents and organolithium compounds react with to give carboxylates: In metal carbon dioxide complexes, serves as a ligand, which can facilitate the conversion of to other chemicals. The reduction of to CO is ordinarily a difficult and slow reaction: Photoautotrophs (i.e. plants and cyanobacteria) use the energy contained in sunlight to photosynthesize simple sugars from absorbed from the air and water: The redox potential for this reaction near pH 7 is about −0.53 V "versus" the
Carbon dioxide cleaning In addition, care must be taken to prevent the concentration of carbon dioxide in the work area from exceeding safe levels. Some commercial grades of carbon dioxide may contain traces of heavy hydrocarbons, which can be left behind on the surface being cleaned. Abrasive particles originating in the cleaning equipment itself may need to be filtered out as well. The low temperature of the carbon dioxide stream can also induce moisture condensation on the part, which may be mitigated with hot plates, heat guns, heat lamps, or dry boxes. Ionization caused by the flowing gas can result in potentially damaging