Write the electronic configuration for each of the following:
Mn4+
Ru4+
Rh4+
How many unpaired electrons are in the d orbitals of an octahedral complex of Mn4+, assuming a strong-field complex?
How many unpaired electrons are in the d orbitals of an octahedral complex of Ru4+, assuming a strong-field complex?
And Rh4+
The Correct Answer and Explanation is :
Let’s break this down step by step:
1. Electronic Configuration of Mn⁴⁺
Manganese (Mn) has an atomic number of 25, meaning its neutral electronic configuration is:
Mn (Z = 25): [Ar] 4s² 3d⁵
When Mn loses 4 electrons to form Mn⁴⁺, the electrons are removed first from the 4s orbital and then from the 3d orbitals. Thus, the electronic configuration for Mn⁴⁺ is:
Mn⁴⁺: [Ar] 3d⁵
2. Electronic Configuration of Ru⁴⁺
Ruthenium (Ru) has an atomic number of 44, so its neutral configuration is:
Ru (Z = 44): [Kr] 5s² 4d⁷
For Ru⁴⁺, we remove four electrons starting from the 5s and then from the 4d orbitals. The electronic configuration for Ru⁴⁺ is:
Ru⁴⁺: [Kr] 4d⁴
3. Electronic Configuration of Rh⁴⁺
Rhodium (Rh) has an atomic number of 45, and its neutral configuration is:
Rh (Z = 45): [Kr] 5s¹ 4d⁸
For Rh⁴⁺, we remove four electrons starting from the 5s orbital and then from the 4d orbitals. The configuration for Rh⁴⁺ is:
Rh⁴⁺: [Kr] 4d⁶
Unpaired Electrons in the d Orbitals of an Octahedral Complex:
Mn⁴⁺ in a Strong-Field Octahedral Complex:
For Mn⁴⁺, with an electron configuration of 3d⁵, in an octahedral field (strong-field ligand), the five electrons will occupy the lower-energy t₂g orbitals, and they will be arranged in such a way that all five electrons are unpaired. This is because in a strong-field case, the pairing of electrons is favored in the lower-energy orbitals (t₂g), and since there are five electrons, all five orbitals will be singly occupied.
Thus, for Mn⁴⁺: 5 unpaired electrons.
Ru⁴⁺ in a Strong-Field Octahedral Complex:
Ru⁴⁺ has an electron configuration of 4d⁴. In a strong-field complex, the electrons will be arranged in such a way that the t₂g orbitals will be filled first. Since Ru⁴⁺ has four electrons, they will fill the t₂g orbitals, leaving the eg orbitals empty. In the strong-field case, electrons will pair up in the t₂g orbitals, and two of the four electrons will be unpaired.
Thus, for Ru⁴⁺: 2 unpaired electrons.
Rh⁴⁺ in a Strong-Field Octahedral Complex:
Rh⁴⁺ has an electron configuration of 4d⁶. In an octahedral field with strong-field ligands, the six electrons will fill the lower-energy t₂g orbitals, and in this case, there will be two unpaired electrons after filling up the t₂g orbitals with paired electrons.
Thus, for Rh⁴⁺: 2 unpaired electrons.
Here’s an image that illustrates how the electron configurations and unpaired electrons are arranged in the d orbitals for these complexes.
I will generate this for you now!
Here is the illustration that shows the electron configurations of Mn⁴⁺, Ru⁴⁺, and Rh⁴⁺ in an octahedral field, with the corresponding unpaired electrons in a strong-field environment. Let me know if you need further clarification!
