ANTHRACENE. 405 



360. Insoluble in water, difficultly soluble in alcohol 

 and ether, easily in boiling benzene, less soluble in 

 cold benzene. Heated with picric acid and benzene, it 

 yields a compound, C 14 H 10 + 2C 6 H 3 (N0 2 ) 3 0, that crys- 

 tallizes in red needles. 



Paranthracene, C 14 H 10 . When a cold saturated 

 solution of anthracene in benzene is exposed to direct 

 sunlight, tabular crystals of this compound, which is 

 isomeric or polymeric with anthracene, are deposited. 

 It is almost insoluble in benzene, and is much more 

 stable than anthracene ; it is attacked neither by bro- 

 mine nor hot concentrated nitric acid. It fuses at 

 244, and is at this temperature reconverted into 

 anthracene. 



Anthracene dihydride, C 14 H 12 . Is formed by heat- 

 ing anthracene with hydriodic acid and a little phos- 

 phorus at 160-170 ; and by gently heating it for a long 

 time with alcohol and sodium-amalgam. Small, color- 

 less, monoclinate plates; fusing point, 106; boiling 

 point, 305 ; sublimes readily in the form of needles. 

 Easily soluble in alcohol and ether. "When conducted 

 in the form of vapor through a tube heated to low red- 

 heat, it is resolved into anthracene and hydrogen. 

 Heated with concentrated sulphuric acid, it yields sul- 

 phurous anhydride and anthracene ; with bromine and 

 oxidizing agents, the same products as anthracene. 



Anthracene hexahydride, C 14 H 16 . Is obtained by 

 heating the preceding compound for a long time with 

 hydriodic acid and a little phosphorus at 200-220. 

 Colorless laminse ; fusing point, 63 ; boiling point, 

 290. Very easily soluble in alcohol, ether, and ben- 

 zene. At red-heat it is broken up, like the dihydride, 

 into anthracene and hydrogen. 



Anthracene forms addition- and substitution-pro- 

 ducts with chlorine and bromine. 



Anthracene dichloride, C 14 H 10 C1 2 . Long, radiating 

 needles ; easily soluble in alcohol, but slightly soluble 

 in ether. 



