Question

Give the decreasing order of reactivity opf diazonium ion coupling with phenol.
a. I. `p-NO_2-C_6H_4 overset (o+)N_2` II. `p-Cl-C_6 H_4 overset (o+) (N_2)`
III. `C_6 H_5 overset (o+) (N_2)` IV. `p-Me-C_6 H_4 overset (o+) (N_2)`
V. ` p-MeO- C_6 H_4 overset (o+) (N_2)`
b. I. ` p-NO_2 -C_6 H_4 overset (o+) (N_2)` II. `m-NO_2 - C_2-C_6H_4 overset (o+) (N_2)`
III. `p-Cl- C_6H_4 overset (o+) (N_2)` IV. `m-Cl-C_6H_4 overset (o+)(N_2)` IV. `Phoveset (o+) (N_2)`
c. I. `m-NO_2 -C_6 H_4 overset (o+) (N_2)` II. ``m-MeO-C_6 H_4 overset (o+) (N_2)` III. `p- MeO - C_6 H_4 overset (o+) (N_2)` IV. ` o-MeO-C_6H_4 overset (o+) (N_2)` IV. ` Ph oveset (o+) (N_2)`.

Answer 1

The more ` EWG` in diazonium ion, the faster the coupling is .
a. `(I) gt (II) gt (III) gt (IV) gt (V)`
` (I) rArr (p-NO_2, - I`, and `-R ), (II) rArr (p-CI, -I)`,
`(I) rArr` Standard
`(IV) rArr ( -p Me, + I , and H.C.)`
(IV) `rArr [p-MeO-, -I` , and `+ R` , net `ED` power of ` MeO- ` is greater than ` ED` power of `(Me -)` group]
b. `(I) gt (II) gt IV gt (III) gt (V)`
`rArr (p-No_2, -I and -R)`,
`(II) rArr (m -NO _2, only -1)`
`(IV) rArr (m -Cl, -I`, but `-I "at" m gt p` and `- I "of" NO _2 -I "of" CL )`.
(III) `rArr (p-Cl, )`
. (V) `rArr` Standear
C. `(I) gt (II) gt (V) gt (IV) gt (II)`
`rArr (m- NO_2`, lony `-I) (II) rArr (m- MeO -, only -I)` (V) `rArr` Standard (IV) , `rArr (0.MeO, -I` and `+R, "net" ED)`
(III) `rArr [p-MeO- , - I`, and `+ R` but -I at `p- lt o`- so net `ED `opwer of (III) (IV)]