Question

Which of the following is not an ortho-para directing group?
A. $C{F_3}$
B. $CC{l_3}$
C. $-CH = CH - COOH$
D. $-Na \to - C$

Answer 1

Electron donating groups are ortho-para directing groups whereas electron withdrawing groups are meta directing groups.

Complete step by step answer:
The activating group directs the reaction to the ortho or para position which means the electrophile substitutes the hydrogen that is on Carbon 2 or Carbon 4. Ortho-para directing groups are electron donating groups. Examples of ortho-para directors are ethers, amines, alkyl groups, thiols and halogens.
The deactivating group directs the reaction to the meta position, it means that electrophile substitute the hydrogen on Carbon 3. Examples of meta directors are nitriles, carbonyl compounds (such as aldehydes, ketones, esters) alkyl groups, nitro groups, sulfones.
Due to the strong +I effect, $C{F_3}$ is an electron withdrawing group, it withdraws electron density away from the ring, thus leaving less available for the ring to use in a nucleophilic attack. It also deactivates the ring. It is a strong deactivating group and prefers to direct incoming substituent to meta position. It makes the meta position more reactive. It is a meta director.
$CC{l_3}$ has an inductive electronegative effect i.e. –I effect because it has highly electronegative Cl atoms due to which C becomes positively charged and pulls electrons. It is a strong deactivating group. So, it is also a meta director.
$-CH = CH - COOH$ is an ortho-para directing electron donating group as it experiences resonance, a delocalization of electrons.
$-Na \to - C$ is not an ortho-para directing group.

Therefore, the correct option is (A), (B) and (D).

Note:
For ortho - para directing groups, there should be partial negative charge at the ortho and para positions. Due to +R effect, halides are ortho-para directing as well as due to –I effect lead over +R this is a deactivating group.