9.24 Write down the IUPAC name for each of the following complexes and indicate the oxidation state, electronic configuration and coordination number. Also give stereochemistry and magnetic moment of the complex:

(i) K[Cr(H2O)2(C2O4)2].3H2

(ii) [Co(NH3)5Cl]Cl2       

(iii) [CrCl3(py)3]  

 (iv) Cs[FeCl4]        

 (v) K4[Mn(CN)6]     

(i) K[Cr(H2O)2(C2O4)2].3H2

The IUPAC name of the complex is 
Potassium diaquadioxalatochromate (III) trihydrate. 
The oxidation state of chromium =  +3
The electronic configuration is 3d3;  t2g3 
Coordination number = 6
Stereochemistry: The compound shows both optical and geometrical isomerism. The structures are as follows:
 

Magnetic moment, µ = \(\sqrt{n(n+2)}\)
 = 

The number of unpaired electron(n) = 3
                                  = 3(3+2)= 15~ 4BM
(ii) [Co(NH3)5Cl-]Cl2 
IUPAC name: Pentaamminechloridocobalt(III) chloride
Oxidation state of Co = +3
Coordination number = 6 Shape:
octahedral.
Electronic configuration: d6:t2g6.

 
Stereochemistry:
Magnetic Moment = 0
(iii) [CrCl3(py)3]   
IUPAC name: Trichloridotripyridinechromium (III)
Oxidation state of chromium = +3
Electronic configuration for d3 = t2g3
Coordination number = 6 Shape:
octahedral.
Stereochemistry:
Both isomers are optically active. Therefore, a total of 4 isomers exist.'
Magnetic moment, μ = n(n+2)                                      = 3(3+2)                                      = 15                                       ~4BM
(iv) Cs[FeCl4]   
IUPAC name: Caesium tetrachloroferrate (III)
Oxidation state of Fe = +3
Electronic configuration of d6 = eg2t2g3
Coordination number = 4
Shape: tetrahedral
Stereochemistry: optically inactive Magnetic
moment:
μ = n(n+2)    = 5(5+2)    = 35 ~ 6 BM
 (v) K4[Mn(CN)6]   
(v) K4[Mn(CN)6]
Potassium hexacyanomanganate(II)
Oxidation state of manganese = +2
Electronic configuration: d5+ : t2g5
Coordination number = 6 Shape:
octahedral.
Streochemistry: optically inactive
Magnetic moment, μ = n(n+2)                                      = 1(1+2)                                      = 3                                      = 1.732 BM