What is Photochemical Gas? What kind of gas is phosgene

It is a branch of photochemistry that studies the photophysics and photochemical processes of atoms and molecules in the gaseous state.

With the development of new technologies such as flash photolysis chemical kinetics, laser spectroscopy, and ultra-high vacuum molecular beams, research in this field has gradually improved. For example, it is possible to study the photochemical primary products of gases and the dynamics of photodissociation. In the analysis of chemical reaction products, the concentration of tens of thousands or even a few molecules can be determined, and the configuration, internal energy and orientation of the product molecules can also be analyzed, and the time resolution of the measurement can reach nanoseconds or even picoseconds.

It has been found that the reactivity of atoms (e.g., carbon, oxygen, sulfur) and radicals (e.g., C2O, CH2) in the excited state of electrons is very different from that of the corresponding atoms and radicals in the ground state. These findings, combined with traditional final product analysis and quantum yield measurements, have greatly contributed to the understanding of photochemical processes, especially those of gases. These studies are of great significance for understanding the research of isotope enrichment and separation, atmospheric impurities, and gas-phase photochemical synthesis.

The formation process of gas photochemistry is very complex, inorganic and organic compounds are involved in the reaction, inorganic compounds are few, the reaction of inorganic compounds has been defined, there are many organic compounds, and the reaction is quite complex. Some people say that the whole process should be described in 102 reactions, and the complexity can be imagined. What is certain at the moment:

The pollutants involved in the photochemical smog caused by visible sunlight in the troposphere are mainly nitrogen dioxide, nitric oxide, carbon monoxide and hydrocarbons, which are primary pollutants emitted by automobiles, oil refining industries and petrochemical industries, as well as secondary pollutants such as ozone, peroxyacetyl nitrate pan and aldehydes. Photochemical smog is a light blue smoke that is very toxic and different from ordinary soot exhaust gases produced by nitrogen oxides and hydrogen carbides emitted from automobile and factory chimneys by ultraviolet sunlight. The main components of gas photochemistry are a series of oxidants such as ozone, aldehydes, peroxyacetyl nitrate, alkyl nitrate, and ketones.

Hydrocarbons and NOx in the atmosphere are a pollutant, which can undergo chemical reactions under ultraviolet irradiation in sunlight and derive various secondary pollutants. The phenomenon of smoke pollution formed by a mixture of primary and secondary pollutants (gases and particulate matter) is called photochemical smog. NOX is the main component of this smoke, and because it first appeared in Los Angeles in 1946, it is also called Los Angeles type smoke to distinguish it from soot smoke (London type smoke).

Phosgene, also known as carbonyl chloride, is a colorless, highly toxic acidic gas.

The chemical formula is CoCl, which is an important organic intermediate, a very active electrophile, easy to hydrolyze the panicle, is a violently asphyxiating poisonous gas, and is highly toxic. The toxicity of phosgene is very high, and even small doses can cause great harm to the human body, and even death. Phosgene is 8 times more toxic than chlorine and is a typical temporary agent.

It can cause coughing, nausea, vomiting, and even toxic pulmonary edema in severe cases, and strict precautions must be taken when using it. Danger to life.

Phosgene is a reactive electrophile that is easily hydrolyzed. Therefore, when using phosgene, strict protective measures must be taken, such as wearing gas masks, wearing protective clothing, etc. At the same time, phosgene has a wide range of industrial applications, such as for the synthesis of organic compounds, the manufacture of polycognitive complexes, etc.

Phosgene is an important organic intermediate, but due to its severe toxicity and liveliness, the production and use of phosgene should be strictly controlled in order to avoid harm to the environment and human beings.

Characteristics of phosgene:

1. Very high activity.

Phosgene is a very reactive electrophile, which makes it extremely reactive with other compounds, capable of generating a wide range of organic compounds. This high degree of reactivity makes phosgene valuable in a wide range of industrial applications, such as for the synthesis of organic compounds and the manufacture of polymers.

2. Severe toxicity.

Phosgene is very toxic to the human body, and its toxicity is 8 times greater than that of chlorine, which is a typical temporary poison. Mild exposure to phosgene may cause symptoms such as coughing, nausea, and vomiting, while severe exposure may lead to toxic pulmonary edema and even life-threatening. Therefore, when using phosgene, strict protective measures must be taken, such as wearing gas masks, wearing protective clothing, etc., to ensure personal safety.

3. Easy hydrolysis.

Phosgene reacts easily with water in the air to produce carbonic acid and carbon dioxide. This characteristic makes the phosgene unstable and prone to decomposition reactions. When storing and transporting phosgene, special care needs to be taken to avoid contact with water to prevent accidents.

Molecular formula C3Cl6O3

Molecular Weight CAS number 32315-10-9

White crystals. There is a phosgene-like odor; Solid density, melt density. Melting point 79 83, boiling point 203 206 760torr.

It has strong stability, and only a small amount of decomposition at the boiling point generates chloromethyl chloroformate and phosgene. Insoluble in water, soluble in ether, THF, benzene, cyclohexane, chloroform, carbon tetrachloride, 1,2-dichloroethane and other organic solvents. One molecule solid three phosgene can be decomposed into three molecule gas phosgene, compared with gas phosgene, it has the advantages of transportation, safe use, convenient measurement, reverse drop reaction, and the reaction is close to the equivalent.

In industry, it is only treated as a general toxic substance. In medicine, pesticides, organic chemicals and polymer synthesis, it can replace phosgene or double phosgene to participate in the reaction.

The initial decomposition temperature of solid phosgene is 130, and the decomposition begins at 90 in a humid atmosphere, which should be stored in a dry and cool place, away from the fire source, and separated from organic amines.

phosgene is an important organic intermediate in pesticides; Today's Medicine; Engineering plastics; Polyurethane materials have many uses as well as in the military.

In the production of pesticides, it is used to synthesize carbaryl carbaryl insecticide; Rapid dicarb; Many varieties such as leafhopper powder are also used for the production of fungicides carbendazim and a variety of herbicides, China's Linxiang Amino Chemical Plant and Ningyang Pesticide Factory have become the production base of carbamate pesticides, and Ningyang Pesticide Factory has been able to produce 43 varieties.

Isocyanate products produced with phosgene as raw material, such as TDI, MDI, PAPI are polyurethane rigid foams; soft bubbles; Elastomer; An important raw material for artificial leather; Some varieties of isocyanates are widely used in polyurethane coatings; There are also special varieties for binders, such as Lekner gum.

It is used in the dye industry to produce dye intermediates such as scarlet acid, and in the defense industry it is used to produce the neutral agent dimethyldiphenylurea and as a military poison gas.

Chloroformates produced with phosgene are pesticides; Medicine; Intermediates in organic synthesis such as polymerization initiators. When the phosgene direct method or transesterification method is used to produce engineering plastic polycarbonate, phosgene is required as raw material.

Phosgene is an important chemical raw material.

You can ask the company that specializes in this kind of industrial equipment.

Like Jiangsu Barel or the Western Regions, people will do some phosgene, also known as carbonyl chloride, highly toxic, slightly soluble in water, more soluble in benzene, toluene, etc. It is made from a mixture of carbon monoxide and chlorine by activated carbon. Phosgene is a colorless gas at room temperature, with a smell of rotting grass, unstable chemical properties, and is rapidly hydrolyzed in case of water to generate hydrogen fluoride.

It is one of the high-temperature pyrolysis products of fluoroplastics. used as an intermediate in organic synthesis, pesticides, drugs, dyes and other chemical products. Aliphatic chlorocarbons (such as carbon tetrachloride, chloroform, trichloroethylene, etc.) can produce phosgene when burned.

Phosgene in the environment mainly comes from production processes such as dyes, pesticides, and pharmaceuticals. Phosgene is a violently asphyxiating poisonous gas, and high concentrations can cause pulmonary edema. It is about 10 times more toxic than chlorine, but it has no accumulation effect in the body.

When prepared in the laboratory, carbon tetrachloride can be used to react with oleum acid. Carbon tetrachloride is heated to 55-60, and oleum sulfuric acid is added dropwise, that is, the phosgene that escapes occurs, and if liquid phosgene is used, the phosgene generated is condensed.

Reaction equation: SO3 +CCL4 SO2Cl2 +COCL2