Question

For the octahedral complexes of Fe³⁺ in SCN– (thiocyanato-S) and in CN– ligand environments, the difference between the spin-only magnetic moments in Bohr magnetons (when approximated to the nearest integer) is [Atomic number of Fe = 26]

Answer 1

SCN– is weak field effect (WFE) ligand whereas CN– is strong field effect (SFE) ligand

Spin only magnetic moment = √5(5+2) =√35 BM

Spin only magnetic moment =​ ​√1(1+2) =√3 BM

Difference =​ ​√35 -√3