Question

Give the oxidation state, d-orbital occupation and coordination number of the central metal ion in the following complexes: 
(i) \(K_3[Co(C_2O_4)_3] \)
(ii)\( cis-[Cr(en)_2Cl_2]Cl \)
(iii) \((NH_4)_2[CoF_4] \)
(iv) \([Mn(H_2O)_6]SO_4\)

Answer 1

(i) \(K_3[Co(C_2O_4)_3] \)
The central metal ion is \(Co.\) 
Its coordination number is \(6\). 
The oxidation state can be given as:
\(x-6 =-3 \)
\(x =+3 \)
The d orbital occupation for\( Co^{ 3+}\) is \(t_{2g}^{ 6}e_g^{0}.\)

(ii) \(cis-[Cr(en)_2Cl_2]Cl \)
The central metal ion is \(Cr. \)
The coordination number is \(6.\) 
The oxidation state can be given as:
\(x+2(0)+2(-1)=+1 \)
\(x - 2 = +1\)
\(x = +3 \)
The d orbital occupation for \(Cr^{3+}\) is \(t_{2g}^{3} .\)

(iii) \((NH_4)_2[CoF_4]\) The central metal ion is\( Co. \)
The coordination number is \(4. \)
The oxidation state can be given as: 
\(x-4 =-2 \)
\(x=+2\) The d orbital occupation for \(Co^{2+} \)is \(e_g^{4}\space  t_{2g} ^{3}.\)

(iv) \([Mn(H_2O)_6]SO_4 \)The central metal ion is \(Mn.\) 
The coordination number is \(6\).
The oxidation state can be given as: 
\(x+0=+2 \)
\(x=+2\) The d orbital occupation for \(Mn \) is \(t_{2g}^{3}\space  e_g^{2} .\)