Which of the following complexes

Question:
Which of the following complexes is homoleptic?

(i) [Co(NH3)6]3+

(ii) [Co(NH3)4 Cl2]+

(iii) [Ni(CN)4]2–

(iv) [Ni(NH3)4Cl2]

Solution:

Option (i) [Co(NH3)6]3+ and (iii) [Ni(CN)4]2– are the answers.