About the Author: About the author John Coyle is currently Lecturer in Chemistry at the Open University. His interest in organic photochemistry started during research at Oxford University, and has expanded to include mechanistic and synthetic aspects, and more recently, the role of photochemistry in a range of biological processes involving proteins. He has previously written, in collaboration with John Barltrop, Excited States in Organic Chemistry, and Principles of Photochemistry, and was involved in the production of the Open University's major undergraduate course, 'Photochemistry: Light, Chemical Change and Life'.