eguruchela

Trichloromethane


Chloroform is an organic compound with formula CHCl3. It is a colorless, sweet-smelling, dense liquid that is produced on a large scale as a precursor to PTFE and refrigerants, but the latter application is declining. The molecule adopts tetrahedral molecular geometry with C3v symmetry. Chloroform was synthesized independently by several investigators circa 1831

(1) Moldenhawer, a German pharmacist from Frankfurt am Oder, appears to have produced chloroform in 1830 by mixing chlorinated lime with ethanol; however, he mistook it for Chloräther

(2) Samuel Guthrie, an American physician from Sackets Harbor, New York, also appears to have produced chloroform in 1831 by reacting chlorinated lime with ethanol; however, he also believed that he had prepared chloric ether.

(3) Liebig carried out the alkaline cleavage of chloral

(4) Soubeirain obtained the compound by the action of chlorine bleach on both ethanol and acetone.

Chloroform is produced by heating a mixture of chlorine and either chloromethane or methane. At 400–500 °C, a free radical halogenation occurs, converting these precursors to progressively more chlorinated compounds:

  • CH4 + Cl2 → CH3Cl + HCl
  • CH3Cl + Cl2 → CH2Cl2 + HCl
  • CH2Cl2 + Cl2 → CHCl33+ HCl
  • Chloroform undergoes further chlorination to yield carbon tetrachloride (CCl4):
  • CHCl3 + Cl2 → CCl4 + HCl