Title:  Quinone 
CAS Registry Number:  106-51-4 
CAS Name:  2,5-Cyclohexadiene-1,4-dione 
Additional Names:  p-quinone;  1,4-benzoquinone;  1,4-cyclohexadienedione 
Molecular Formula:  C6H4O2 
Molecular Weight:  108.09 
Percent Composition:  C 66.67%, H 3.73%, O 29.60% 
Literature References:  Made by oxidation of aniline with sodium dichromate in presence of sulfuric acid.  Laboratory prepn from hydroquinone:  Vliet, Org. Synth. 2, 85 (1922); also Org. Synth. coll. vol. I (2nd ed., 1941).  Cf.  Underwood, Walsh, ibid. 16, 73 (1936).  Toxicity study:  Woodard et al., Fed. Proc. 8, 348 (1949). 
Properties:  Yellow monoclinic prisms from water or petr ether.  Penetrating odor resembling that of chlorine.  Irritating vapors.  d420 1.318.  mp 115.7°.  Sublimes [sublimation velocities in vacuo:  Kempf, J. Prakt. Chem. [2] 78, 236 (1908)].  Volatile with steam.  Absorption spectrum:  Hantzsch, Ber. 49, 522 (1916).  Dipole moment:  0.67.  Polemic over correct values:  Paoloni, J. Am. Chem. Soc. 80, 3879 (1958).  Slightly sol in water; sol in alcohol, ether, hot petr ether, alkalies.  LD50 orally in rats:  130 mg/kg (Woodard). 
Melting point:  mp 115.7° 
Density:  d420 1.318 
Toxicity data:  LD50 orally in rats:  130 mg/kg (Woodard) 
CAUTION:  Potential symptoms of overexposure are eye and skin irritation, conjunctivitis; keratitis.  See NIOSH Pocket Guide to Chemical Hazards (DHHS/NIOSH 97-140, 1997) p 272. 
Use:  Oxidizing agent; in photography; manuf dyes; manuf hydroquinone; tanning hides; making gelatin insol; strengthening animal fibers; as reagent.   |