Anthracene, also called scintillation crystal, is a condensed-ring aromatic hydrocarbon containing three rings. Its molecular formula is C14H10. Triphenyl medium composed of solid polycyclic aromatic hydrocarbons. It is found in coal tar. The centers of the three rings of anthracene are in a straight line and are the isomers of phenanthrene. Anthracene is a colorless flaky crystal; has blue-violet fluorescence; melting point 215 ° C, boiling point 340 ° C, relative density 1.283 (25/4°C); easy sublimation; insoluble in water, difficult to dissolve in ethanol and ether, easily soluble in hot benzene. The anthracene molecule has a high chemical activity at the 9,10 position. It is oxidized with nitric acid to form 9,10-anthraquinone (see the anthraquinone for its structural formula), which is an important intermediate for the synthesis of anthraquinone dyes; it is reduced with sodium and ethanol to produce 9, 10-dihydroanthracene; 9,10-dichloroanthracene is formed by adding chlorine, which loses a molecule of hydrogen chloride and becomes 9-chloroanthracene; anthracene can also be used as a conjugated diene, with maleic anhydride, etc. Diers-Alder reaction occurred in 9,10. Industrially, crude anthracene is separated from the anthracene oil fraction obtained by fractionating coal tar by crystallization, and then purified by sublimation. High purity anthracene can be used as a scintillator for scintillation counters. On October 27, 2017, the list of carcinogens published by the International Agency for Research on Cancer of the World Health Organization initially compiled the reference.
Figure 1. Chemical structure of Anthracene.
Coal tar, which contains about 1.5% of anthracene, remains the main source of the material. Common impurities are phenanthrene and carbazole. The classic laboratory method for the preparation of anthracene is the ring dehydration of o-methyl or o-methylene substituted diaryl ketones in a so-called Elbs reaction.
Anthracene, a wide bandgap organic semiconductor, is used as a scintillator for high-energy photon, electron, and alpha particle detectors. Anthracene can be used to dope plastics, such as polyvinyltoluene, to produce plastic scintillators, which are equivalent to water and used in radiation therapy dosimetry. The emission spectrum of anthracene peaks between 400 nm and 440 nm.It is also used in wood preservatives, pesticides and coatings. Anthracene is commonly used as a UV tracer in conformal coatings applied to printed wiring boards. Anthracene tracers can inspect conformal coatings under UV light. Anthracene is also used in the manufacture of anthraquinone.
Anthracene is converted mainly to anthraquinone, a precursor to dyes.