[Fe(CN)6]
3– has magnetic
moment of a single unpaired electron while [FeF6]
3– has a paramagnetic
moment of five unpaired electrons [CoF6]
3– is paramagnetic with four
unpaired electrons while [Co(C2O4)3]
3– is diamagnetic This apparent
anomaly is explained by valence bond theory in terms of formation of
inner orbital and outer orbital coordination entities [Mn(CN)6]
3–, [Fe(CN)6]
3–
and [Co(C2O4)3]
3– are inner orbital complexes involving d
2sp
3 hybridisation,
the former two complexes are paramagnetic and the latter diamagnetic