萘是一種有機化合物,分子式C10H8,白色,易揮發并有特殊氣味的晶體.從煉焦的副產品煤焦油中大量生產,而用于合成染料、樹脂等。通常的衛生球就是用萘制成的。1958年以來，代替滴滴涕等氯化產品的甲萘威投產后，用作殺蟲劑原料的比例有所增加。萘的用途分配，各國有所不同，大致用于生產鄰苯二甲酸酐約占70%，染料中間體（如β－萘酚）和橡膠加工助劑約占15%,殺蟲劑約占6%,鞣革劑約占4%，染料生產較少的國家,如美國則用于生產殺蟲劑的比例較大。

Naphthalene is an organic compound with the molecular formula C10H8. It is a white, volatile, and odorous crystal. It is produced in large quantities from coal tar, a byproduct of coking, and is used in the synthesis of dyes, resins, etc. The usual sanitary balls are made of naphthalene. Since 1958, the proportion of carbaryl used as a pesticide raw material has increased after it was put into production to replace chlorinated products such as DDT. The allocation of uses of naphthalene varies among countries, with approximately 70% being used for the production of phthalic anhydride and dye intermediates such as β－ Naphthol and rubber processing additives account for about 15%, insecticides account for about 6%, and tanning agents account for about 4%. Countries with less dye production, such as the United States, have a larger proportion of insecticides.

萘 - 理化性質

Naphthalene - Physical and Chemical Properties

物理性質

physical property

密度

density

熔點80.5℃,沸點217.9℃,凝固點,80.5℃,閃點78.89℃,折射率1.58212（100℃）恒容燃燒熱：40.19KJ/g(標準大氣壓，298.15K） 恒壓燃燒熱：40205J/g(標準大氣壓，298.15K）。

Melting point 80.5 ℃, boiling point 217.9 ℃, freezing point 80.5 ℃, flash point 78.89 ℃, refractive index 1.58212 (100 ℃), constant volume combustion heat: 40.19KJ/g (standard atmospheric pressure, 298.15K), constant pressure combustion heat: 40205J/g (standard atmospheric pressure, 298.15K).

不溶于水，溶于乙醇和乙醚等

Insoluble in water, soluble in ethanol and ether, etc

易揮發，易升華

Easy to evaporate and sublimate

溶于乙醇后，將其滴入水中，會出現白色渾濁。

After dissolving in ethanol, dropping it into water will result in white turbidity.

溫和氧化劑得醌，強烈氧化劑得酸酐。萘環比側鏈更易氧化，所以不能用側鏈氧化法制萘甲酸。電子云密度高的環易被氧化。

A mild oxidant yields quinone, while a strong oxidant yields anhydride. Naphthalene rings are more easily oxidized than side chains, so side chain oxidation cannot be used to produce naphthoic acid. Rings with high electron cloud density are prone to oxidation.

（2） 萘的還原

(2) Reduction of naphthalene

萘可與5個H2加成生成十氫化萘。

Naphthalene can be added with 5 H2 to form decahydronaphthalene.

（3）萘的加成

(3) Addition of naphthalene

（4）萘的親電取代反應

(4) Electrophilic substitution reaction of naphthalene

萘的α-位比β-位更易發生親電取代反應。α-位取代兩個共振式都有完整的苯環。β-位取代只有一個共振式有完整的苯環。

Naphthalene α- Bitwise ratio β- The site is more prone to electrophilic substitution reactions. α- Both resonance formulas have a complete benzene ring. β- There is only one resonance formula with a complete benzene ring in place of a substitution.

在萘環上主要發生親電取代，同苯環一樣，但活性比苯環強

The electrophilic substitution mainly occurs on the naphthalene ring, similar to the benzene ring, but with stronger activity than the benzene ring

從中間對稱的兩個C旁邊的C開始標，其中1，4，5，8號碳活性完全一樣（稱為α碳），2，3，6，7號碳性質完全一樣（稱為β碳）。

Start with the C next to the symmetrical two Cs in the middle, where the carbon activities of numbers 1, 4, 5, and 8 are exactly the same (referred to as α Carbon), carbon numbers 2, 3, 6, and 7 have identical properties (referred to as β Carbon).

一般情況下，α碳活性大于β碳，取代基在α位上，這是由動力學控制，溫度較高時，α碳[4] 上取代基會轉移到β碳上。

In general, α Carbon activity greater than β Carbon, substituent in α In terms of position, this is controlled by dynamics. When the temperature is high, α The substituents on carbon [4] will transfer to β On carbon.

但在萘的弗瑞德-克來福特酰基化反應，不加熱卻生成了α位和β位的混合物。如用硝基甲烷為溶劑，則主要生成β酰化產物 。

But in the Friedel-Crafterford acylation reaction of naphthalene, it was generated without heating α Bitwise sum β A mixture of bits. If nitromethane is used as a solvent, it mainly generates β Acylation products.

修改：中間的兩個碳不編號。

Modification: The two carbons in the middle are not numbered.

萘 - 萘的用途

The Use of Naphthalene Naphthalene

廣泛用作制備染料、樹脂、溶劑等的原料，也用作驅蟲劑（俗稱衛生球或樟腦丸）。起取代反應比起加成反應容易。

Widely used as a raw material for preparing dyes, resins, solvents, etc., and also as a repellent (commonly known as sanitary balls or camphor balls). Substitution reactions are easier than addition reactions.

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