CHEM 3303 - Supplementary Problems - Part 2

Review: Linear Combinations of Atomic Orbitals (LCAO's)

Question 1
Give an appropriate set of LCAO's for a square pyramidal sp3d geometry assuming:

  1. The axial-base angle = 90° [Solution]
  2. The axial-base angle > 90° [Solution]

Symmetry Adapted Linear Combinations (SALCs)

Question 1
For the following molecules determine the symmetry labels for the SALCs:

  1. PdCl42- (square planar) [Solution]
  2. SiCl4 [Solution]
  3. cis-PtF2Cl22- [Solution]
  4. SF6 [Solution]

Question 2
For the following molecules draw a picture of each SALC:

  1. PdCl42- (square planar) [Solution]
  2. SiCl4 [Solution]
  3. cis-PtF2Cl22- [Solution]
  4. SF6 [Solution]

Molecular Orbital Diagrams (σ-bonding)

Question 1
For the following molecules construct an MO Diagram to describe the σ-bonding:

  1. trans-SF2Cl4 [Solution]
  2. NH4+ [Solution]
  3. SF6 [Solution]

Molecular Orbital Diagrams (π-bonding)

Question 1
For the following molecules construct an MO Diagram to describe the π-bonding:

  1. SiF4 (s,px,py,pz orbitals used for σ-bonding) [Solution]
  2. GeH2Cl2 (s,px,py,pz orbitals used for σ-bonding) [Solution]
  3. SnCl62- (s,px,py,pz, dz2, dx2-y2 orbitals used for σ-bonding) [Solution]

Question 2
For PtCl42- (square planar), s, px, py and dx2-y2 are used for σ-bonding. Construct an MO Diagram to describe the π-bonding:

  1. for π-bonding perpendicular to the plane [Solution]
  2. for π-bonding parallel to the plane [Solution]