The leaving group is that functional group which is ejected with `overline e^, s` of the `sigma` -bond in a reaction. Better the leaving group, faster is the reaction. The relative leaving ability of the leaving group `X` in `(R - X)` is increased by :
(i) The polarisability of `(R - X)` bond.
(ii) The stability of `X^(Ө)`.
(iii) The degree of stabilisation through solvation of `X`.
(iv) The strength of `(R - X)` bond.
The leaving group tendency is also called fugacity.
Which statement is wrong ?

Options

A. In polar aprotic solvents such as `DMSO, DMF`, and `DMA`, the fugacity order is `I^(Ө) gt Br^(Ө) gt Cl^(Ө) gt F^(Ө)`.
B. Strong bases are good leaving groups.
C. The leaving group order of the following is :
`overset (Ө) OH gt RO^(Ө) gt CH -= C^(Ө) gt overset (Ө) NH_2`.
D. Charges species are good leaving groups than neutral species.

Answer

B

Explanation

Weak bases are good leaving groups.
Acidic order : `H_2 O gt ROH gt CH -= CH gt NH_3`
Basic order : `overset (Ө) O H lt R O^(Ө) lt CH -= C^(Ө) lt overset (Ө) N H_2`
Weaker the base, better is the leaving group.
Leaving group order : `overset (Ө) O H gt RO^(Ө) gt CH -= C^(Ө) gt overset (Ө) N H_2`.