Whatcan be inferred from the magnetic moment values of the followingcomplex species?
Example Magnetic Moment (BM)
K4[Mn(CN)6] 2.2
[Fe(H2O)6]2+ 5.3
K2[MnCl4] 5.9
Whatcan be inferred from the magnetic moment values of the followingcomplex species?
Example Magnetic Moment (BM)
K4[Mn(CN)6] 2.2
[Fe(H2O)6]2+ 5.3
K2[MnCl4] 5.9
Magnetic moment (
)is given as
.
Forvalue n= 1, 
.
Forvalue n= 2, 
.
Forvalue n= 3, 
.
Forvalue n= 4, 
.
Forvalue n= 5, 
.
(i) K4[Mn(CN)6]
Forin transition metals, the magnetic moment is calculated from thespin-only formula. Therefore,
Wecan see from the above calculation that the given value is closestto
.Also, in this complex, Mn is in the +2 oxidation state. This meansthat Mn has 5 electrons in the d-orbital.
Hence,we can say that CN− is a strong field ligand thatcauses the pairing of electrons.
(ii) [Fe(H2O)6]2+
Wecan see from the above calculation that the given value is closestto
.Also, in this complex, Fe is in the +2 oxidation state. This meansthat Fe has 6 electrons in the d-orbital.
Hence,we can say that H2O is a weak field ligand anddoes not cause the pairing of electrons.
(iii) K2[MnCl4]
Wecan see from the above calculation that the given value is closestto
.Also, in this complex, Mn is in the +2 oxidation state. This meansthat Mn has 5 electrons in the d-orbital.
Hence,we can say that Cl− is a weak field ligand and doesnot cause the pairing of electrons.
Magnetic moment ()is given as.
Forvalue n= 1, .
Forvalue n= 2, .
Forvalue n= 3, .
Forvalue n= 4, .
Forvalue n= 5, .
(i) K4[Mn(CN)6]
Forin transition metals, the magnetic moment is calculated from thespin-only formula. Therefore,
Wecan see from the above calculation that the given value is closestto.Also, in this complex, Mn is in the +2 oxidation state. This meansthat Mn has 5 electrons in the d-orbital.
Hence,we can say that CN− is a strong field ligand thatcauses the pairing of electrons.
(ii) [Fe(H2O)6]2+
Wecan see from the above calculation that the given value is closestto.Also, in this complex, Fe is in the +2 oxidation state. This meansthat Fe has 6 electrons in the d-orbital.
Hence,we can say that H2O is a weak field ligand anddoes not cause the pairing of electrons.
(iii) K2[MnCl4]
Wecan see from the above calculation that the given value is closestto.Also, in this complex, Mn is in the +2 oxidation state. This meansthat Mn has 5 electrons in the d-orbital.
Hence,we can say that Cl− is a weak field ligand and doesnot cause the pairing of electrons.
