Spectroscopy – the interaction of electromagnetic waves (light) with matter – is a vast subject with many different sub-branches used by every sort of scientist from the biologist to the astrophysicist. At first glance, the different techniques appear to have very little in common with each other. In this course, we shall see how the same basic principles can be used to appreciate the essence of the wide variety of techniques used. We will work through the electromagnetic spectrum, starting with microwave spectroscopy. This is concerned with the rotations of molecules. We shall see how this technique, in the form of radio astronomy, is used to detect molecules on the other side of the galaxy whilst, closer to home, it may be used to follow pollutants in our atmosphere.
We will then look at infrared spectroscopy which deals with the vibrations of bonds. Starting with the simple relatively low resolution spectroscopy used in chemical laboratories and we will progress to higher resolution spectroscopy where rotational sub-structure can also be detected. We shall see how this technique has found a variety of applications including detecting the gases emitted during a volcanic eruption.
Visible light, UV light and even the x-rays commonly generated and used in hospitals can all interact with matter, both atoms and molecules, by promoting electrons from one energy level to another. Such processes help to give us an understanding of why everyday things are coloured and even the composition of distant astronomical events.
Finally, we shall look at radio-waves and how these interact with atomic nuclei when placed in a magnetic field. The resulting technique, nuclear magnetic resonance (NMR), is perhaps the most important tool available to the chemist for determining chemical structure. We shall progress from the very simplest NMR experiment and how this is used in chemical laboratories, through more complicated examples whereby protein structures are determined and finally onto the applications in medicine where the technique, known as medical resonance imaging, is used to elucidate internal body structure.
Some very basic quantum mechanics will be introduced to illustrate some of the theory behind these techniques. No great mathematical ability is necessary!
