The triphenylmethyl radical (often shorted to trityl radical) is an
organic compound with the formula (C
6H
5)
3C. It is a
persistent radical
In chemistry, a radical, also known as a free radical, is an atom, molecule, or ion that has at least one unpaired valence electron.
With some exceptions, these unpaired electrons make radicals highly chemically reactive. Many radicals spont ...
. It was the first
radical
Radical may refer to:
Politics and ideology Politics
*Radical politics, the political intent of fundamental societal change
*Radicalism (historical), the Radical Movement that began in late 18th century Britain and spread to continental Europe and ...
ever to be described in
organic chemistry. Because of its accessibility, the trityl radical has been heavily exploited.
Preparation and properties
It can be prepared by
homolysis of
triphenylmethyl chloride 1 by a metal like
silver or
zinc in
benzene or
diethyl ether. The radical 2 forms a
chemical equilibrium with the
quinoid-type
dimer 3 (
Gomberg's dimer). In benzene the concentration of the radical is 2%.
Solutions containing the radical are
yellow; when the temperature of the solution is raised, the yellow color becomes more intense as the equilibrium is shifted in favor of the radical (in accordance with
Le Chatelier's principle).
When exposed to air, the radical rapidly oxidizes to the
peroxide, and the color of the solution changes from yellow to colorless. Likewise, the radical reacts with
iodine
Iodine is a chemical element with the symbol I and atomic number 53. The heaviest of the stable halogens, it exists as a semi-lustrous, non-metallic solid at standard conditions that melts to form a dee