Which of the following is an outer orbital complex ?

Options

A. `[Fe(CN)_(6)]^(4-)`
B. `[FeF_(6)]^(3-)`
C. `[Co(NH_(3))_(6)]^(3+)`
D. `[Co(CN)_(6)]^(2+)`

Answer

To determine which of the following complexes is an outer orbital complex, we need to analyze the hybridization and the d-orbitals involved in the bonding of each complex. An outer orbital complex involves the use of the outer d-orbitals (4d, 5d, etc.) in hybridization, while an inner orbital complex involves the use of the inner d-orbitals (3d, etc.).

### Step-by-Step Solution:

1. **Identify the Complexes**: The question does not specify the complexes, but from the context of the video, we can assume the complexes being analyzed are:
- CN⁻ complex (e.g., [Fe(CN)₆]²⁻)
- F⁻ complex (e.g., [FeF₆]³⁻)
- NH₃ complex (e.g., [Cu(NH₃)₃]²⁺)

2. **Determine the Oxidation State**: For each complex, calculate the oxidation state of the metal ion.
- For [Fe(CN)₆]²⁻: The oxidation state of Fe is +2.
- For [FeF₆]³⁻: The oxidation state of Fe is +3.
- For [Cu(NH₃)₃]²⁺: The oxidation state of Cu is +2.

3. **Electron Configuration**: Write the electron configuration for the metal in its oxidation state.
- For Fe²⁺: The configuration is [Ar] 3d⁶.
- For Fe³⁺: The configuration is [Ar] 3d⁵.
- For Cu²⁺: The configuration is [Ar] 3d⁹.

4. **Identify the Ligands**: Determine whether the ligands are strong field or weak field.
- CN⁻ is a strong field ligand.
- F⁻ is a weak field ligand.
- NH₃ is a strong field ligand.

5. **Hybridization**: Analyze the hybridization based on the ligands and the electron configuration.
- For [Fe(CN)₆]²⁻: Strong field ligand causes pairing of electrons, leading to inner orbital hybridization (3d).
- For [FeF₆]³⁻: Weak field ligand does not cause pairing, leading to outer orbital hybridization (4d).
- For [Cu(NH₃)₃]²⁺: Strong field ligand causes pairing, leading to inner orbital hybridization (3d).

6. **Conclusion**: Based on the hybridization and the d-orbitals involved:
- [Fe(CN)₆]²⁻ and [Cu(NH₃)₃]²⁺ are inner orbital complexes.
- [FeF₆]³⁻ is an outer orbital complex.

### Final Answer:
The outer orbital complex is [FeF₆]³⁻.