Question

What can you conclude about the strength of metal-N bonds (in [M(NH₄)₄]²⁺ compared to metal-O bonds in [M(H₂O)₆]²⁺_. Explain.

Answer 1

In both the complexes metal is in =2 oxidation state. According to sectrochemical series, NH₃ is more stonger ligand than H₂O. NH₃ is a strong sigma donor ligand than H₂O as in ammonia the ligating atom is nitrogen which is less elecronegative than oxygen which is ligationg atom in water. Thus the donation of sigma electron to the metal will be more in the case of ammonia as comared to water ligand. Thus metal-N bonds (in [M(NH₄)₄]²⁺ is stronger as compared to metal-O bonds in [M(H₂O)₆]²⁺_.