JEE MainChemistryCoordination Compounds
Given below are two statements: one is labelled as Assertion (A) and the other is labelled as Reason (R). Assertion (A): According to Crystal Field Theory, anionic ligands should exert a greater splitting effect than neutral ligands. Reason (R): In the spectrochemical series, anionic ligands are found at the lower end, acting as weak field ligands. In the light of the above statements, choose the most appropriate ans
Options
- ABoth (A) and (R) are correct and (R) is the correct explanation of (A).
- BBoth (A) and (R) are correct but (R) is NOT the correct explanation of (A).
- C(A) is correct but (R) is not correct.
- D(A) is not correct but (R) is correct.
Correct answer
B. Both (A) and (R) are correct but (R) is NOT the correct explanation of (A).
Step-by-step solution
Assertion (A) is correct. Crystal Field Theory (CFT) assumes that ligands are point charges (for anions) or point dipoles (for neutral molecules). Based on purely electrostatic considerations, an anionic ligand with a full negative charge should repel the metal's d-electrons more strongly than a neutral dipole, thereby causing a greater crystal field splitting. Reason (R) is also correct. Experimentally, anionic ligands such as halides ( I ⁻ , Br ⁻ , Cl ⁻ ) are found at the lower end of the spectrochemical series a