Question

How can one distinguish between strong field complexes and weak field complexes

Answer 1

Strong field complexes are the ones in which the ligand attached is strong field which causes pairing of the t2g electrons .

The strength of ligands is given by a spectrochemical series in which sigma acceptor are the strongest followed by sigma donor and lastly pi donors which are the weakest .

So strong field ligands form low spin complexes because they allow the pairing of electrons .

So by calculating the magnetic moment , we can calculate the spin and hence the no. Of number of unpaired electrons .

On the other hand., Weak field complexes form high spin complexes .