Fluorine continues to intrigue chemists who overcome the challenge of handling this remarkable halogen and work to develop varied methods for synthesising fluorine compounds. The unique properties of these materials, ranging from inert perfluorocarbons and fluoropolymers to a multitude of other fascinating fluorinated compounds, firmly established their place amidst the technological achievements of the 20th Century. Fluorine substitution in biologically active compounds has become particularly significant in recent years. This book presents new and significant research in this field.