The complex $[Co(NH_3)_4(NO_2)_2]Cl$ will show.........

(A) Linkage isomerism
(B) lonization isomerism
(C) Coordination isomerism
(D) Geometrical isomerism

Choose the correct answer from the options given below:

(A), (B) and (D) only

The correct answer is Option (1) → (A), (B) and (D) only

Why (brief):

• (A) Linkage isomerism: NO₂ can bind through N (nitro) or O (nitrito) → linkage isomers.
• (B) Ionization isomerism: a coordinated NO₂⁻ can swap with the counter Cl⁻ to give an ionization isomer (e.g. $[Co(NH_3)_4(NO_2)Cl]NO_2$​).
• (D) Geometrical isomerism: in an octahedral $[Co(NH_3)_4(NO_2)_2]^+$ the two identical NO₂ ligands can be cis or trans.

(C) Coordination isomerism does not apply (requires more than one metal center / both cationic and anionic complex parts).