What are the main uses of 1,2-diiodobenzene?

1,2-Dichloroethane is an organic compound with a wide range of uses. In the context of "Tiangong Kaiwu", although there is no exact record of 1,2-dichloroethane at that time, it can be compared to the way the use of various things in the book is described, and its main uses can be described for you.

First, it is used as a solvent. 1,2-Dichloroethane has good solubility and can dissolve many organic substances, such as oils, resins, rubbers, etc. In industrial production, it is often used in the manufacturing process of paints, coatings, adhesives, etc., by its dissolution effect, the ingredients are uniformly mixed to obtain high-quality products. Just as "Tiangong Kaiwu" describes the role of various solvents in the production process of harmony and uniformity, 1,2-dichloroethane also plays a similar role in this regard.

Second, as a chemical raw material. It is crucial in the field of organic synthesis and is a key intermediate for the preparation of many important chemical products such as vinyl chloride and ethylenediamine. Taking the preparation of vinyl chloride as an example, 1,2-dichloroethane can be prepared by dehydrochlorination reaction. Vinyl chloride is a monomer for the production of polyvinyl chloride (PVC), which is widely used in modern industry and life. This process is like the process of many substances in "Tiangong Kaiwu" being converted into new products through a series of conversions. 1,2-dichloroethane is used as a starting material and chemically changed to generate other more valuable chemicals.

Third, it is also used in the field of metal cleaning. Because of its strong solubility to oil and other pollutants, it can effectively remove oil, grease and other organic impurities on the metal surface, making the metal surface clean and laying a good foundation for subsequent processing, painting and other processes. This is in line with the concept of surface treatment of materials involved in "Tiangong Kaiwu" to facilitate subsequent operations, all of which are for specific process purposes through specific material treatment.

Fourth, it can also be used as a fumigant. In agricultural warehousing, 1,2-dichloroethane can kill pests and molds, and ensure the storage safety of agricultural products such as grain. Just as in ancient times, 1,2-dichloroethane used specific methods to prevent insects and mildew to preserve food, it plays a similar role in protecting stored items.

What are the physical properties of 1,2-diiodobenzene?

1,2-Dichloroethane is a colorless and transparent liquid with a chloroform-like odor. Its physical properties are as follows:
- ** Boiling point **: about 83.5 ° C. This boiling point determines that it will change from liquid to gaseous state under certain temperature conditions. During industrial distillation or separation, depending on this boiling point, 1,2-dichloroethane can be separated from other mixtures with different boiling points by controlling the temperature.
- ** Melting point **: -35.7 ° C. Indicates that at temperatures below this temperature, 1,2-dichloroethane will solidify into a solid state. This property should be considered when storing or transporting at low temperatures to prevent damage to containers or pipes due to solidification. < Br > - ** Density **: The relative density (water = 1) is about 1.26. Because the density is greater than that of water, it will sink to the bottom when mixed with water. This can be used for preliminary stratification separation operations when treating wastewater or mixed liquids containing 1,2-dichloroethane.
- ** Solubility **: Slightly soluble in water, miscible with most organic solvents such as ethanol, ether, and chloroform. This solubility makes it often used as a solvent in organic synthesis reactions. It can dissolve a variety of organic compounds, provide a homogeneous environment for chemical reactions, and promote the smooth progress of the reaction.
- ** Volatile **: has a certain degree of volatility. Under normal temperature and pressure, it will gradually evaporate into the air. This requires that when using and storing 1,2-dichloroethane, it must be ventilated to avoid its accumulation in a limited space and cause safety risks, because the volatile vapor and air can form explosive mixtures.

What are the chemical properties of 1,2-diiodobenzene?

1% 2C2-dibromoethane is an organic compound. It is a colorless liquid at room temperature and has a chloroform-like odor. It has many important chemical properties:
First, a typical substitution reaction of halogenated alkanes. Due to the high activity of bromine atoms, 1% 2C2-dibromoethane can be substituted with a variety of nucleophiles. Taking co-heating with sodium hydroxide aqueous solution as an example, bromine atoms will be replaced by hydroxyl groups to form ethylene glycol: $BrCH_2CH_2Br + 2NaOH\ xrightarrow {\ Delta} HOCH_2CH_2OH + 2NaBr $. This reaction is often used in organic synthesis to prepare alcohols.
Second, elimination reaction. When 1% 2C2-dibromoethane is co-heated with potassium hydroxide alcohol solution, a digestion reaction occurs, removing two molecules of hydrogen bromide to form acetylene: $BrCH_2CH_2Br + 2KOH\ xrightarrow {alcohol,\ Delta} HC\ equiv CH ↑ + 2KBr + 2H_2O $. This is an important method for preparing alkynes.
Third, the addition reaction. The carbon-bromine bond in 1% 2C2-dibromoethane can be broken under specific conditions and added to the unsaturated bond. For example, under the action of a catalyst, it can undergo an addition reaction with ethylene to generate 1% 2C1% 2C2% 2C2-tetrabromoethane: $BrCH_2CH_2Br + CH_2 = CH_2\ xrightarrow {catalyst} Br_2CHCHBr_2 $.
Fourth, 1% 2C2-dibromoethane has certain chemical stability, but under conditions such as light or high temperature, the carbon-bromine bond is prone to homogenization, generating free radicals, which in turn triggers a series of free radical reactions.
In addition, 1% 2C2-dibromoethane has a density greater than water, is insoluble in water, and is soluble in organic solvents such as ethanol, ether, and chloroform. Because of its bromine atom, its relative molecular weight is large and its boiling point is also high. In the field of organic synthesis, 1% 2C2-dibromoethane is often used as an intermediate for the synthesis of various complex organic compounds, which is of great significance in both industrial and scientific research fields.

What are the synthesis methods of 1,2-diiodobenzene?

The synthesis methods of 1,2-dibromoethane are as follows:
First, the direct addition method of ethylene and bromine. The ethylene gas is slowly introduced into the bromine-containing carbon tetrachloride solution, and the two undergo an addition reaction. The reaction principle is that the ethylene molecule has a carbon-carbon double bond, and the bromine atom of bromine launches an electrophilic attack on the double bond. After the double bond is opened, two bromine atoms are added to the two carbon atoms connected by the original double bond, thereby generating 1,2-dibromoethane. The reaction conditions of this method are relatively mild, the operation is relatively simple, and the purity of the product is quite high. However, bromine is highly corrosive and toxic, so careful protection must be taken during operation, and the reaction is an exothermic reaction, and the reaction temperature needs to be properly controlled to prevent the reaction from being too violent.
Second, ethanol is co-heated with sodium bromide and concentrated sulfuric acid. Ethanol first reacts with concentrated sulfuric acid to form ethyl hydrogen sulfate, and then the bromine ions ionized by sodium bromide react with ethyl hydrogen sulfate to form 1,2-dibromoethane. The raw materials of this method are relatively common and easy to obtain, but the reaction process is more complicated, concentrated sulfuric acid is highly corrosive, and the control of the reaction conditions is also very critical. If the temperature is too high, it is easy to cause side reactions such as dehydration of ethanol to form ethylene, which affects the yield and purity of the product.
Third, the synthesis method using acetylene as the raw material. First, acetylene is catalyzed to hydrogenate to produce ethylene, and then 1,2-dibromoethane is obtained by the addition of ethylene and bromine. Although this path is a little complicated, if the raw material acetylene is easy to obtain, it is also a feasible method. First, acetylene is hydrogenated to produce ethylene under the action of an appropriate catalyst (such as Lindela catalyst), which can precisely control the degree of hydrogenation and avoid excessive hydrogenation Then ethylene and bromine are added to form the target product, which can be improved by controlling the reaction conditions.

What are the precautions for storing and transporting 1,2-diiodobenzene?

For 1% 2C2-dibromoethane, it is necessary to pay attention to many matters during storage and transportation.

The first storage place. It should be placed in a cool and ventilated warehouse, away from fire and heat sources, because it is flammable, and there is a risk of combustion and explosion caused by open flames and high heat. The temperature of the warehouse should be strictly controlled, and it should not exceed 30 ° C to prevent the temperature from being too high and causing its chemical properties to be unstable. And it should be stored separately from oxidizing agents, acids, bases, etc., and must not be mixed. Because of contact with it or violent chemical reaction, it is dangerous to safety. The storage area should also be equipped with suitable materials to contain leaks to prevent it from being difficult to dispose of in time after accidental leakage.

The rules of transportation. When transporting, the vehicle must be equipped with the corresponding variety and quantity of fire fighting equipment and leakage emergency treatment equipment. Summer transportation should be selected in the morning and evening, and avoid high temperature during the day to prevent its volatilization from being exacerbated due to excessive temperature and increase the danger. During transportation, it should be ensured that the container does not leak, collapse, fall, or damage. To follow the prescribed route, do not stop in densely populated areas and residential areas to reduce the harm to the public in case of an accident. When loading and unloading personnel operate, they need to load and unload lightly to prevent damage to the packaging and containers. If the packaging is damaged, dibromoethane leaks, which is easy to cause poisoning and other accidents. After the transportation vehicle is used, it should also be thoroughly cleaned and disinfected to prevent the residual 1% 2C2-dibromoethane from contaminating the subsequent transportation items.