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
Electrochemical reduction of carbon dioxide carbon monoxide (CO). In carbon fixation, plants convert carbon dioxide into sugars, from which many biosynthetic pathways originate. The catalyst responsible for this conversion, RuBisCo, is the most common protein on earth. Some anaerobic organisms employ enzymes to convert CO to carbon monoxide, from which fatty acids can be made. In industry, a few products are made from CO, including urea, salicylic acid, methanol, and certain inorganic and organic carbonates. In the laboratory, carbon dioxide is sometimes used to prepare carboxylic acids. No electrochemical process involving CO has been commercialized. The electrochemical reduction of carbon dioxide to CO is usually