What is the state of naphthalene 5 and what does naphthalene mean?

Naphthalene is a colorless flake crystal with a melting point and a boiling point of 218, with a special smell and easy sublimation. Insoluble in water, soluble in hot ethanol and ether. Naphthalene is an important chemical organic raw material and is also commonly used as a mothproofing agent.

Naphthalene is a crystal with a melting point. During the heating process, the temperature of the solid naphthalene gradually increases and it begins to melt; The melting process, although the heating continues in this process, the temperature remains unchanged, this temperature is the melting point of naphthalene, and the melting point of naphthalene is 80; Continue to heat, the naphthalene is melted, and the liquid naphthalene will continue to heat up as it is heated.

The structure of naphthalene is similar to benzene and is also a closed conjugated system. On the naphthalene ring, the delocalization of p electrons is not completely averaged as in the benzene ring, but the electron cloud density is higher on the -carbon atom, followed by the -carbon atom, and smaller on the two carbon atoms shared in the middle, so the electrophilic substitution reaction generally occurs at the -position.

From the perspective of resonance concept, when the -position and -position of naphthalene are replaced, different intermediate positive ions are formed, which can be represented by the following resonance structures.

1) Substitution reaction.

Halogenated. Chlorine gas is passed into the benzene solution of naphthalene, and under the action of catalyst or ferric chloride, -chloronaphthalene is mainly obtained.

Nitrify. Naphthalene is nitrified with mixed acid, and the main product is -nitronaphthalene. The reaction rate is much faster than the nitrification of benzene, and the reaction can be carried out at room temperature.

Nitronaphthalene is a yellow needle-like crystal with a melting point of 61, insoluble in water, soluble in organic solvents, and used in the preparation of -naphthylamine.

Sulfonation. The sulfonation reaction of naphthalene is also reversible, and the position of the sulfonic acid group is related to the reaction temperature. Naphthalene and concentrated sulfuric acid interact below 80, and the main product is -naphthalene sulfonic acid; At higher temperatures (165), the main product is -naphthalene sulfonic acid.

The sulfonation of naphthalene is reversible and again a competing reaction of -position and -position.

2) Addition reactions. Naphthalene is easily reduced to 1,4-dihydronaphthalene, or 1,2,3,4-tetrahydronaphthalene under the action of ethanol and sodium.

If further reduction, more intense conditions are required, such as at 1216 1520kpa, decahydronaphthalene can be directly obtained by catalytic hydrogenation.

Decahydronaphthalene has two conformational isomers, i.e., two cyclohexanes fused in either cis or trans phases, respectively. The boiling point of cis is 194, and the boiling point of trans is 185.

3) Oxidation reaction. Naphthalene is more easily oxidized than benzene, and different oxidation products can be obtained according to the reaction conditions. For example, naphthalene is oxidized with chromium oxide in an acetic acid solution, and one of the rings is oxidized to quinone, but in low yield.

Under strong conditions, one of the rings is oxidized and ruptured, resulting in phthalic anhydride.

Phthalic anhydride is an important chemical raw material, it is the raw material for many synthetic resins, plasticizers, dyes, etc.

When the substituted naphthalene is oxidized, which ring is oxidized and ruptured depends on the nature of the substituent on the naphthalene ring. During oxidation, the rings with higher electron cloud density, that is, the more active rings, are easily broken by oxidation to form phthalic acid or its derivatives. This also indicates that naphthalene is formed by two benzene rings sharing two adjacent atoms.

This is because the nitro group is an electron-withdrawing group that passivates the benzene ring, while the amino group is an electron-repellent group that activates the benzene ring.

Organic compound, chemical formula C10H8. White crystals, with a special smell, easy to sublimate.

Naphthalene is the simplest fused cyclic aromatic hydrocarbon, with the formula C10H8, which consists of 2 benzene rings.

It is made by fusing two adjacent carbon atoms. Colorless, toxic, easily sublimated and with a peculiar smell of flaky crystals. Coal tar, a by-product from coking.

and petroleum distillation in large quantities, mainly used for the synthesis of phthalic anhydride.

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Introduction

The most important fused aromatic hydrocarbons in the industry.

The pure product is with camphor wood.

Odor of white crystals, melting point 80-82 . It is mainly used in the production of phthalic anhydride and dyes.

intermediates, rubber additives and pesticides, etc.

Since 1958, the proportion of menacarb used as a raw material for pesticides has increased after the production of methylnaphthyl products such as DDT has been put into production. The distribution of the use of naphthalene varies from country to country, roughly used for the production of phthalic anhydride accounts for about 70%, dye intermediates (such as naphthol) and rubber processing aids account for about 15%, pesticides account for about 6%, tanning agents account for about 4%, and countries with less dye production, such as the United States, use a larger proportion for the production of pesticides.

The above content reference: Encyclopedia - Naphthalene.

Naphthalene is an organic compound.

Naphthalene is a fused cyclic aromatic hydrocarbon, which is an organic compound. Molecular formula C10H8, colorless, toxic, sublimation and special odor of flaky crystals. It is produced in large quantities from coal tar, a by-product of coking, and petroleum distillation, mainly for the synthesis of phthalic anhydride, etc.

The health balls that have been told blindly are made of naphthalene, but due to the toxicity of naphthalene, the use of naphthalene as an ingredient has now been banned in the health balls.

Exposure to naphthalene is associated with hemolytic anemia, resulting in liver and nervous system damage, cataracts, and retinal hemorrhage. Naphthalene is reasonably expected to be a carcinogen in humans and may be associated with an increased risk of laryngeal and colorectal cancers.

On October 27, 2017, the list of carcinogens released by the World Health Organization's International Agency for Research on Cancer (IARC) was preliminarily sorted out for reference, and naphthalene was included in the list of carcinogens in category 2b.

The most important fused aromatic hydrocarbons in the industry. The pure product is a white crystal with the smell of camphor wood, melting point. It is mainly used in the production of phthalic anhydride, dye intermediates, rubber additives and pesticides.

Since 1958, the proportion of carnacarb used as a raw material for pesticides has increased since the production of methylcarb as a substitute for chlorinated products such as DDT.

The distribution of the use of naphthalene varies from country to country, and it is roughly used for the production of phthalic anhydride about 70%, dye intermediates (such as naphthol) and rubber processing aids account for about 15%, pesticides account for about 6%, tanning agents account for about 4%, and countries with less dye production, such as the United States, are used for the production of pesticides.

Molecular structure and chemical properties:

Structure: Two connected benzene rings.

1. Oxidation reaction of naphthalene.

Mild oxidant to obtain quinone, strong oxidant to obtain acid anhydride. Naphthalene is more susceptible to oxidation than the side chains, so naphthalic acid cannot be prepared by side chain oxidation. Rings with high electron cloud density are susceptible to oxidation.

For example, -nitronaphthalene is oxidized to give 3-nitrophthalic anhydride, and -naphthalamine is oxidized to phthalic anhydride (the ring where the amino group is located is oxidized).

2. Reduction reaction (addition reaction) of naphthalene

Naphthalene can be added with 5 hydrogen to form decahydronaphthalene.

3. Electrophilic substitution reaction of naphthalene.

The -position of naphthalene is more susceptible to electrophilic substitution than the -position. The two resonant resonant formulas have a complete benzene ring of the repentant rock. The -bit substitution has only one resonance formula with a complete benzene ring.

Electrophilic substitution mainly occurs on the naphthalene ring, which is the same as the benzene ring (easy to substitute, difficult to add), but the activity is stronger than that of the benzene ring.

Starting from the C mark next to the two C's in the middle symmetry (the two carbons in the middle are not numbered), where carbon 1, 4, 5, and 8 are exactly the same activity (called carbon), and carbon 2, 3, 6, and 7 are exactly the same in nature (called carbon).

In general, the carbon activity is greater than that of carbon, the substituents are in place, which is controlled by kinetics, and at higher temperatures, the substituents on the carbon will be transferred to the carbon.

However, in the Fred-Clefford acylation reaction of naphthalene, a mixture of bits and bits is formed without heating. If nitromethane is used as a solvent, the acylation product is mainly generated.

Naphthalene: There is a sanitary ball and tar odor, volatile at room temperature, sublimated at the melting point temperature, volatilized with water vapor, its petroleum ether solution is reddish-purple fluorescence under mercury lamp, 1g soluble in 13ml methanol or ethanol, benzene and toluene, 2ml chloroform or carbon tetrachloride, carbon disulfide, soluble in ether and volatile oil, insoluble in water, organic analysis as insoluble dye crystallization can be used as a solvent, naphthalene is a white solid, easy to evaporate. Fuels such as petroleum and coal contain naphthalene.

Also known as white tar and tar camphor, it has been used in mothballs and moth flakes to produce naphthalene when burning tobacco or wood, and it has a strong but not unpleasant odor.

The main commercial use of naphthalene is in the manufacture of polyvinyl chloride (PVC) plastics, and its primary consumer use is in mosquito repellent and toilet deodorant blocks.

1-methylnaphthalene and 2-methylnaphthalene are compounds related to naphthalene, 1-methylnaphthalene is a transparent liquid, and 2-methylnaphthalene is a solid; Both can be smelled in very low concentrations in air and water, 1-methylnaphthalene and 2-methylnaphthalene are used in the manufacture of other chemicals such as dyes and resins, and 2-methylnaphthalene is also used in the manufacture of vitamin K.

Naphthalene is a chemical substance, an aromatic hydrocarbon compound, commonly used in the manufacture of dyes, fluorescents and pesticides.

Naphthalene is a white or light yellow crystal that is usually purified before it can be used. Its chemical formula is C??h?

It belongs to polycyclic aromatic hydrocarbon compounds. Naphthalene has high stability and chemical inertness, and is not easily volatile at room temperature. Among them, the aromatic ring structure of naphthalene is widely used in many chemical synthesis and important industrial production.

For example, naphthalene can be used to prepare n-substituted naphthalene sulfonyl chloride, used as intermediate compounds such as dyes, and can also be used as a raw material for the manufacture of fluorescent agents. At the same time, naphthalene is also one of the important raw materials for the manufacture of insecticides, fungicides and herbicides.

It should be noted that due to the strong toxicity and flammability of naphthalene, it has certain harm to the human body and the atmospheric environment. Therefore, its emissions and hazards should be strictly controlled in the process of production, sale, use and treatment. Information about naphthalene can be found in the Safety Data Sheet (MSDS) for safety and use specifications.

The pinyin of naphthalene is nài, and many friends only know its sound, but do not know its meaning. So what does naphthalene mean? What is the explanation of the naphthalene word to the bottom of the finger search? Let's follow me to see the meaning of the word naphthalene What does naphthalene mean?

Meaning of naphthalene word:Naphthalene nài

An organic compound, colorless crystallization, with a special odor, can repel insects, and is often used in the manufacture of sanitary balls, dyes, spices, etc.

Detailed explanation of the word naphthalene:The detailed meaning of the word naphthalene nài

Name: A crystalline aromatic hydrocarbon [naphthalene]. The molecular formula C 10 H 8, which has a special odor and is the most abundant component of coal tar, is usually prepared from distilled coal tar and from coke oven gas**, and consists of two fused benzene rings. It is mainly used as a raw material for the synthesis of early god machines and as a fumigant (such as in sanitary balls).