A Manual of the Chemistry of the Carbon Compounds

TEE CARSON COMPOUNDS. 431
combining units are saturated with carbon, whilst the atoms 4, 5, 9
and 10, are combined with carbon-atoms to •which hydrogen is
attached. The functions of the atoms 1, 3, 6 and 8 will, therefore,
differ from those of the four latter.
Naphthalene forms additive compounds much more readily than
benzene.
HYDRONAPHTHAtBNES.
DiJtydronapfttkalene, or Naphthydrene C10H10.—When naphthalene
is heated with potassium a black compound is formed, having probably
the composition C^ILIL,, inasmuch as water decomposes it
into caustic potash and dinyaronaphthalene. The same hydrocarbon
is produced when naphthalene is heated with 20 parts of concentrated
hydriodic acid to 280°. Ifc is a colourless, oily liquid, boiling at 210°
and possessing a penetrating smell.
FetrdhydronapMhalene CLH18 is obtained by heating 10 parts of
naphthalene with 3 parts of amorphous phosphorus and 9 parts of
hydriodic acid to 250°. It is a liquid, boiling at 205°, and possesses
a peculiar, but not strong odour.
Both hydrides are resolved into naphthalene and hydrogen, when
their vapour is passed through a red-hot tube.
NAPHTHALENE CHLORIDES.
Naphthalene DieMoride C.OH8C1,.—When chlorine is passed over
naphthalene, it melts and absorbs the chlorine completely, the first
product being naphthalene dichloride, a heavy, pale-yellow oil, which
1)y repeated distillation, or by the action of alcoholic potash, kresolved
into hydrochloric acid, and monochloronaphthalene.
Naphthalene Tetrachloride C1OH8C14 is produced by the continued
action of chlorine on the dichloride, and is a solid, crystallizing from
chloroform in transparent rhombic plates, melting at 182°.
DicldoronajpUhydrene Glycol C10HaCl2(OH)2 is obtained by heating
the tetrachloride with 30 parts of water to 190°. It is soluble in
water, and crystallizes from ether in large, hard prisms. By heating
it with acetyl chloride it is converted into the diacetate
CioHgCl^OCjjHgOjg, crystallizing from other in hard, short prisms,
melting at 130°.
fd
Naphthalene Dichlorhydrate C10H8-j ,Q|J* is obtained by dissolving
hthl i ttd l h l id d f lll
naphthalene in concentrated liypochlorous acid, and forms pale-yellow
prisms. Alcoholic potash converts it into naphlhene alcoliol, or
napMJuUene telrahydrojride CwH8(0HJi crystallizing from alcohol in
colourless prisms.