Functional group, formula –CCl3
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Structure of the Trichloromethyl group
The trichloromethyl group is a functional group that has the formula –CCl3. The naming of is group is derived from the methyl group (which has the formula –CH3), by replacing each hydrogen atom by a chlorine atom. Compounds with this group are a subclass of the organochlorines. Some notable examples of compounds with this group are trichloromethane H–CCl
3, 1,1,1-trichloroethane H
3C–CCl
3, and chloral HOC–CCl
3.
The trichloromethyl group has a significant electronegativity.[citation needed] For this reason, trichloromethyl-substituted acids, such as trichloromethanesulfonic acid, are often stronger than the original. For example, the acidity constant (pKa) of trichloroacetic acid HOOC–CCl
3 is 0.77, whereas that of acetic acid is 4.76.[1][2]
By the same principle, the trichloromethyl group generally lowers the basicity of organic compounds, e.g. trichloroethanol.
See also
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