Coordination Complexes and Molecular Formulas

Question 1
Give a perspective drawing for each of the following formulas:

1. η⁵-Cp₂Ni [Solution]
2. fac-CuF₃(H₂O)₃^– [Solution]
3. cis-NiCl₂(PMe₃)₂ [Solution]
4. CoCl₂Br₂^– [Solution]
5. μ-Cl₂-(Cu(dppe))₂ [Solution]

d Orbital Splitting Diagrams

Question 1
Draw and label the energy levels for the d orbitals in a coordination complex for the following geometries:

1. Octahedral [Solution]
2. Octahedral with π-acceptor ligands [Solution]
3. Octahedral with π-donor ligands [Solution]
4. Tetrahedral [Solution]
5. Square Planar [Solution]
6. Trigonal Bipyramidal [Solution]
7. Square-based Pyramid with axial-base angle = 90 ° [Solution]
8. Square-based Pyramid with axial-base angle > 90 ° [Solution]

Ligand Field Stabilisation Energy (LFSE)

Question 1
Calculate the LFSE (in terms of Dq) for the following octahedral d-electron configurations:

1. d³ [Solution]
2. d⁵ (high-spin) [Solution]
3. d⁵ (low-spin) [Solution]
4. d⁹ [Solution]

Question 2
Calculate the LFSE (in terms of Dq) for the following tetrahedral d-electron configurations:

1. d² [Solution]
2. d⁴ [Solution]
3. d⁷ [Solution]
4. d¹⁰ [Solution]

Coordination Complexes and Colour

Question 1
CrO₃ is dark red. Explain why colour is observed. [Solution]

Question 2
trans-NiCl₂(PCy₃)₂ (Cy = cyclohexyl, C₆H₁₁^–) is dark red and NiCl₂(PPh₃)₂ is dark green. Explain why one complex is red and the other is green. [Solution]

Question 3
[Mn(H₂O)₆]Cl₂ is pale red and Mn(CO)₅Br is dark orange. Explain why one complex is pale and the other is dark. [Solution]