Naphthalene is a polycyclic aromatic hydrocarbon, and its molecular formula is C 10H8, which has a mild aromatic smell, while crude naphthalene has a special smell of coal tar. The melting point is 80.2℃ and the boiling point is 265438 08℃. Insoluble in water, soluble in organic solvents such as ethanol and ether. Volatile sublimation, can be distilled with steam. Forming explosive mixture with air; The explosion limit is 0.9%-5.9% by volume.
Molecular structure and chemical properties:
Oxidation of 1 with naphthalene. Quinone in mild state keeps oxidant and anhydride in strong state keeps oxidant. Naphthalene is easier to oxidize than side chain, so it is impossible to prepare naphthoic acid by side chain oxidation. Rings with high electron cloud density are easily oxidized. For example, α -nitronaphthalene is oxidized to 3- nitrophthalic anhydride, and α -naphthylamine is oxidized to phthalic anhydride.
2. Reduction reaction of naphthalene. Naphthalene can be added with five hydrogen atoms to form decalin.
3. Electrophilic substitution of naphthalene. The α position of naphthalene is more likely to cause electrophilic substitution than β position. The two α-substituted * * * modes have complete benzene rings. β -substitution has only one * * * pattern and a complete benzene ring. Electrophilic substitution mainly occurs on naphthalene ring, which is as easy to substitute as benzene ring and difficult to add, but its activity is stronger than benzene ring.
The importance of chemistry
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