Ammonium carbamate

Ammonium carbamate is the inorganic compound with the formula NH4. This salt is formed by the reaction of ammonia with carbon dioxide, and is a white solid that is extremely soluble in water, less so in alcohol. It is unusual in that it will degrade at room temperature. Ammonium carbamate is the inorganic compound with the formula NH4. This salt is formed by the reaction of ammonia with carbon dioxide, and is a white solid that is extremely soluble in water, less so in alcohol. It is unusual in that it will degrade at room temperature. It is prepared by the direct reaction between liquid ammonia and dry ice (solid carbon dioxide): The structure of solid ammonium carbamate has been confirmed by X-ray crystallography. The oxygen centers form hydrogen bonds to the ammonium cation. Ammonium carbamate reverts to carbon dioxide and ammonia even as a solid: It hydrates reversibly: Ammonium carbamate serves a key role in the formation of carbamoyl phosphate, which is necessary for both the urea cycle and the production of pyrimidines. In this enzyme-catalyzed reaction, ATP and ammonium carbamate are converted to ADP and carbamoyl phosphate: The ability of ammonium carbamate to make urea was first discovered in 1870 when Bassarov heated ammonium carbamate in sealed glass tubes at temperatures ranging from 130 to 140 °C. This heating yields urea and water in an equimolar ratio. A typical industrial plant that makes urea can produce up to 1500 tons a day. Ammonia and carbon dioxide is excessively fed to a synthesis reactor in this process. Ammonium carbamate is produced as an intermediate in this reactor and can then be dehydrated to urea according to the following equation: Ammonium carbamate has also been approved by the Environmental Protection Agency as an inert ingredient present in aluminum phosphide pesticide formulations. This pesticide is commonly used for insect and rodent control in areas where agricultural products are stored. The reason for ammonium carbamate as an ingredient is to make the phosphine less flammable by freeing ammonia and carbon dioxide to dilute hydrogen phosphine formed by a hydrolysis reaction. Ammonium carbamate can also be used as a good ammoniating agent, though not nearly as strong as ammonia itself.