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Trifluoromethyl group covalently bonded to an R group. The trifluoromethyl group is a functional group that has the formula-CF 3. The naming of is group is derived from the methyl group (which has the formula -CH 3), by replacing each hydrogen atom by a fluorine atom. Some common examples are trifluoromethane H– CF 3, 1,1,1-trifluoroethane H ...
In the CF 3 radical the fluorine atom is an electron-withdrawing group via the inductive effect but also a weak pi donor through interaction of the fluorine lone pair with the radical center's SOMO. Compared to the methyl radical the CF 3 radical is pyramidal (angle 107.8 °C ) with a large inversion barrier, electrophilic and also more reactive.
In chemistry, a leaving group is defined by the IUPAC as an atom or group of atoms that detaches from the main or residual part of a substrate during a reaction or elementary step of a reaction. [1] However, in common usage, the term is often limited to a fragment that departs with a pair of electrons in heterolytic bond cleavage. [2]
The trifluoromethyl cation is a molecular cation with a formula of CF + 3. It is a carbocation due to its positively charged carbon atom. It is part of the family of carbenium ions, with three fluorine atoms as substituents in place of its hydrogen atoms. [1]
Electron-withdrawing groups exert an "inductive" or "electron-pulling" effect on covalent bonds. The strength of the electron-withdrawing group is inversely proportional to the pKa of the carboxylic acid. [2] The inductive effect is cumulative: trichloroacetic acid is 1000x stronger than chloroacetic acid.
TFA is a stronger acid than acetic acid, having an acid ionisation constant, K a, that is approximately 34,000 times higher, [3] as the highly electronegative fluorine atoms and consequent electron-withdrawing nature of the trifluoromethyl group weakens the oxygen-hydrogen bond (allowing for greater acidity) and stabilises the anionic conjugate ...
The effect is used in a qualitative way and describes the electron withdrawing or releasing properties of substituents based on relevant resonance structures and is symbolized by the letter M. [2] The mesomeric effect is negative ( –M ) when the substituent is an electron-withdrawing group , and the effect is positive ( +M ) when the ...
An electron withdrawing group (EWG) will have the opposite effect on the nucleophilicity of the ring. The EWG removes electron density from a π system, making it less reactive in this type of reaction, [ 2 ] [ 3 ] and therefore called deactivating groups .