Physical Chemistry II (saylor.org)

Physical Chemistry II is quite different from Physical Chemistry I. In this second semester of the Physical Chemistry course, you will study the principles and laws of quantum mechanics as well as the interaction between matter and electromagnetic waves. During the late 19th century and early 20th century, scientists opened new frontiers in the understanding of matter at the molecular, atomic, and sub-atomic scale. These studies resulted in the development of quantum physics, which nowadays is still considered one of the greatest achievements of human mind. While present day quantum physics “zooms in” to look at subatomic particles, quantum chemistry “zooms out” to look at large molecular systems in order to theoretically understand their physical and chemical properties. Quantum chemistry has created certain “tools” (or computational methods) based on the laws of quantum mechanics that make it theoretically possible to understand how electrons and atomic nuclei interact with each other to form any kind of matter, ranging from diamond crystals to DNA strands to proteins to plastic polymers. Using these tools, quantum chemists can simulate complex biological systems, such as nucleic acids, proteins, and even cells, in order to understand their functions and behavior. These tools are increasingly used by researchers at pharmaceutical companies as they need to simulate the interaction of a potential drug molecule with the target receptor, such as a protein binding pocket on the surface of a cell. Scientists use computational tools of quantum chemistry to predict the optical and electronic properties of novel materials to be used in advanced technologies, such as organic photovoltaics (OPVs) for solar energy harvesting and organic light emitting diodes (OLEDs) for electronic displays. In these applications, scientists can “calculate” the range of sunlight frequencies a certain material can absorb or the color of the emitted light in a pixel fabricated using certain molecules. Quantum chemistry treats light as both a wave and a particle and uses wavefunctions to describe systems composed by “tangible” matter, such as electrons and nuclei. A substantial portion of the course is dedicated to the theoretical understanding of the interactions between light (electromagnetic radiations) and matter (molecules, electrons, nuclei, etc.). These interactions are at the base of modern image techniques used in the medical field, such as magnetic resonance imaging (MRI).

This senior course in quantum chemistry usually serves as an introduction to more advanced graduate courses in theoretical chemistry, rather than concluding your degree in chemistry. With the knowledge gained in this course, you will be able to calculate the energies of simple systems, such as small molecules. Keep in mind that these calculations of quantum chemistry are fairly complicated, thus you will learn several approximation techniques to aid your calculations of more advanced molecular systems. You will also be able to correlate the outcome of your calculation to certain physical properties of the molecule. In particular, you will learn how the spectroscopy properties are strictly interconnected with the electronic structure of molecules.

Upon successful completion of this course, the student will be able to:

Describe the difference between classical and quantum mechanics.

Explain the failure of classical mechanics in elucidating the black body radiation, the photoelectric effect, and atomic emission spectra.

Define the wave-particle duality.

Define the uncertainty principle.

Solve the Hamiltonian for a particle in box, on a ring, and on a sphere.

Solve the Schrodinger equation for hydrogen-like systems.

Use technique of approximation to compute the Schrodinger equation for polyatomic systems.

Describe the difference between the Valence Bond and the Molecular Orbital Theories.

Identify the symmetry elements in a molecule.

Predict and explain the outcome of electromagnetic radiations interacting with matter.

Define Raman spectroscopy.

Predict the vibrational spectra of molecules based on their electronic structure.

Explain the selection rules for a molecule to be Raman or IR active.

Explain the difference between fluorescence and phosphorescence.

Describe the principle of operation of LASERs.

Explain the effect of magnetic fields on electrons and nuclei.