Chloromethane

Chloromethane, also called methyl chloride, Refrigerant-40, R-40 or HCC 40, is a chemical compound of the group of organic compounds called haloalkanes. It was once widely used as a refrigerant. It is a colorless extremely flammable gas with a mildly sweet odor. Due to concerns about its toxicity, it is no longer present in consumer products.Chloromethane was first synthesized by the French chemists Jean-Baptiste Dumas and Eugene Peligot in 1835 by boiling a mixture of methanol, sulfuric acid, and sodium chloride. This method is similar to that used today.1ª Step: Cl + O3 → ClO + O22ª Step: ClO + O → Cl + O2Net: O3 + O → 2 O2 Chloromethane, also called methyl chloride, Refrigerant-40, R-40 or HCC 40, is a chemical compound of the group of organic compounds called haloalkanes. It was once widely used as a refrigerant. It is a colorless extremely flammable gas with a mildly sweet odor. Due to concerns about its toxicity, it is no longer present in consumer products.Chloromethane was first synthesized by the French chemists Jean-Baptiste Dumas and Eugene Peligot in 1835 by boiling a mixture of methanol, sulfuric acid, and sodium chloride. This method is similar to that used today. Chloromethane is the most abundant organohalogen, anthropogenic or natural, in the atmosphere. It is a constituent of tobacco smoke. Laboratory cultures of marine phytoplankton (Phaeodactylum tricornutum, Phaeocystis sp., Thalassiosira weissflogii, Chaetoceros calcitrans, Isochrysis sp., Porphyridium sp., Synechococcus sp., Tetraselmis sp., Prorocentrum sp., and Emiliana huxleyi) produce CH3Cl, but in relatively insignificant amounts. An extensive study of 30 species of polar macroalgae revealed the release ofsignificant amounts of CH3Cl in only Gigartina skottsbergii and Gymnogongrus antarcticus. The salt marsh plant Batis maritima contains the enzyme methyl chloride transferase that catalyzes the synthesis of CH3Cl from S-adenosine-L-methionine and chloride. This protein has been purified and expressed in E. coli, and seems to be present in other organisms such as white rot fungi (Phellinus pomaceus), red algae (Endocladia muricata), and the ice plant (Mesembryanthemum crystallinum), each of which is a known CH3Cl producer. Chloromethane has been detected in the low-mass Class 0 protostellar binary, IRAS 16293–2422, using the Atacama Large Millimeter Array (ALMA). It was also detected in the comet 67P/Churyumov–Gerasimenko (67P/C-G) using the Rosetta Orbiter Spectrometer for Ion and Neutral Analysis (ROSINA) instrument on the Rosetta spacecraft. The detections reveal that chloromethane can be formed in star-forming regions before planets or life is formed. Large amounts of chloromethane are produced naturally in the oceans by the action of sunlight on biomass and chlorine in sea foam. However, all chloromethane that is used in industry is produced synthetically. Most chloromethane is prepared by reacting methanol with hydrogen chloride, according to the chemical equation This can be carried out either by bubbling hydrogen chloride gas through boiling methanol with or without a zinc chloride catalyst, or by passing combined methanol and hydrogen chloride vapors over an alumina catalyst at 350 °C (662 °F). A smaller amount of chloromethane is produced by heating a mixture of methane and chlorine to over 400 °C (752 °F). However, this method also results in more highly chlorinated compounds such as dichloromethane, chloroform, and carbon tetrachloride and is usually only used when these other products are also desired.