**RATIONALE**

Quantum chemical calculations are rapidly becoming a viable alternative to experiments as a means to investigate chemistry, and continue to play strong supportive and predictive roles. Electrochemistry takes centre stage in the industrial production of several chemicals, corrosion, enzyme-controlled biological redox processes, batteries and fuel cells. This course is designed to provide students with a deeper understanding of the conceptual basis of some modern physico-chemical theories and methods.

**COURSE DESCRIPTION**

This course explores in considerable depth the fundamentals of computational chemistry and quantum chemistry and their application to molecular structure and properties, and further elaborates on the topic of redox chemistry, which was introduced in the core programme.

**LEARNING OBJECTIVES**

On completion of this course students should be able to:

1.Apply the Hückel molecular orbital approximation to some simple organic molecules.

2.Use the Hartree-Fock algorithm to find orbital energies and ionisation potentials for closed-shell configurations.

3.Use computer software to find equilibrium configurations, and electronic charge distributions of molecules.

4.Derive rate expressions for electron transfer processes.

5.Apply the Marcus theory to homogeneous and heterogeneous redox reactions.

6.Explain the principles underlying some common electroanalytical techniques.

7.Interpret and analyse electrochemical data obtained with cyclic voltammetry and other techniques.

8.Identify the features of dipoles and induced dipoles and relate their dipole moment to the charge, separation of charge and polarisability of atoms and molecules.

9.Model the cohesive and repulsive forces between aggregates of atoms and molecules in terms of the interaction between pairs.

10.Relate the properties of gases and liquids (such as thermal conductivity, viscosity and surface properties of liquids) to the nature and strength of the interaction between units.

**COURSE CONTENT**

__Computational Methods (10 lectures)__

- Hückel molecular orbital approximation.
- Born-Oppenheimer approximation. Potential energy surfaces.
- Hartree-Fock molecular orbital approximation for closed-shell configurations.
- Slater determinant. Density matrix.
- Ionisation potential and Koopman's theorem.
- Molecular conformational energies.
- Charge distributions in molecules. Dipole moment.

__Molecular Interactions
(10 lectures)__

1. Electric dipole moments, polarizabilities, and relative permittivities.

2. Interaction between dipoles and induced dipoles

3. The dispersion interaction, repulsive and total interactions, hydrogen bonding. Role in molecular recognition.

4. Molecular interactions in gases, the kinetic model for the perfect gas.

5. Real gases, van der Waals and virial equations of state.

6. Collisions with walls and surfaces, effusion.

7. Transport properties including diffusion, thermal conductivity and viscosity.

8. Molecular Interactions in liquids, structure and order in liquids.

__Redox Processes and Advanced
Electrochemistry (10 lectures)__

1. Homogeneous and heterogeneous electron transfer.

2. Outer- and inner-sphere reactions.

- Marcus theory for homogeneous and heterogeneous electron transfer.
- Electrified interfaces: the double layer.

5. Ionic transport in solution. Diffusion and migration.

6. Cell design. Liquid junctions.

7. Reversible, irreversible and quasi-reversible electron transfer at electrodes. Butler-

Volmer equation and Tafel plots.

8.Polarography. Potentiostats.

Dynamic techniques: cyclic voltammetry, a/c
voltammetry and impedance methods.