question_answer 27)

  What is spectrochemical series? Explain the difference between a weak field ligand and a strong field ligand.

Answer:

The arrangement of ligands in order of their CHSE ( ) values is known as spectrochemical series. The series is: I-1< Br–< S2–< SCN–<Cl–< F–< OH–< C2O42–< O2–< H2O < NCS–< NH3< en< NO2–< CN–< CO The ligands which cause only a small crystal field splitting are called weak field ligands while those responsible for large splitting are known as strong field ligands. Strong field ligands form low spin complexes. Weak field ligands form high spin complexes.