JEE MainChemistryCoordination Compounds
Consider the two mixed-ligand complexes of nickel: P = [ Ni ( CN )₂( NH ₃)₂] Q = [ NiCl ₂( Br )₂]²⁻ Which of the following statements is correct regarding their geometries and ability to exhibit geometrical isomerism?
Options
- AP is tetrahedral and does not show geometrical isomerism, whereas Q is square planar and shows geometrical iso
- BBoth P and Q are square planar and both exhibit geometrical isomerism.
- CP is square planar and shows geometrical isomerism, whereas Q is tetrahedral and does not show geometrical iso
- DBoth P and Q are tetrahedral and neither exhibits geometrical isomerism.
Correct answer
C. P is square planar and shows geometrical isomerism, whereas Q is tetrahedral and does not show geometrical iso
Step-by-step solution
In complex P = [ Ni ( CN )₂( NH ₃)₂] , the central metal ion is Ni ²⁺ which has a 3 d ^8 configuration. The presence of strong field ligands ( CN ^- ) causes the pairing of 3 d electrons, resulting in dsp ^2 hybridization. Thus, P has a square planar geometry. Square planar complexes of the type Ma ₂ b ₂ can exist as cis and trans isomers, so P exhibits geometrical isomerism. In complex Q = [ NiCl ₂( Br )₂]²⁻ , the central metal ion is Ni ²⁺ ( 3 d ^8 ). Both Cl ^- and Br ^- are weak field ligands, so no pairing of