Consider the transition metal ions Mn^3+ , Cr^3+ , Fe^3+ and Co^3+ and all form low spin octahedral complexes. The correct decreasing order of unpaired electrons in their respective d-orbitals of the…

Question

Consider the transition metal ions Mn^3+ , Cr^3+ , Fe^3+ and Co^3+ and all form low spin octahedral complexes. The correct decreasing order of unpaired electrons in their respective d-orbitals of the complexes is

Accepted Answer

Correct answer: B. (b) For low spin octahedral complexes, electrons fill the t_2g orbitals first before pairing or moving to e_g orbitals. The configuration depends on the number of d-electrons. For Cr^3+ : Electronic configuration is 3d^3. In an octahedral field, the configuration is t_2g^3e_g^0. Number of unpaired electrons (n )=3. For Mn^3+ : Electronic configuration is 3d^4. For low spin, the configuration is t_2g^4e_g^0. Number of unpaired electrons (n )=2. For Fe^3+ : Electronic configuration is 3d^5. For low spin, the configuration is t_2g^5e_g^0. Number of unpaired electrons ( n )=1. For Co^3+ : Electronic configuration is 3d^6. For low spin, the configuration is t_2g^6e_g^0. Number of unpaired electrons ( n )=0. Comparing the number of unpaired electrons: Cr^3+ (3 )> Mn^3+ (2 )> Fe^3+ (1 )> Co^3+ (0 ). The correct decreasing order is Cr^3+> Mn^3+> Fe^3+> Co^3+.

$Consider the transition metal ions Mn^{3 +}, Cr^{3 +}, Fe^{3 +} and Co^{3 +} and all form low spin octahedral complexes. The correct decreasing order of unpaired electrons in their respective d-orbitals of the complexes is$

Solution

More Coordination Compounds PYQs