The department has an international reputation for excellence in many aspects of organic chemistry. It originally established its reputation in ground-breaking work on synthetic dyes and plant pigments, alkaloids and steroids, the biogenesis of natural products and the chemistry of free radicals. The experimental methods and theory behind this work provide the basis of large areas of contemporary organic chemistry. The laboratory is at the leading edge of research with its work on the mechanisms of organic and enzymatic reactions, and the synthesis of new compounds. Many of these compounds have important applications in fields such as pharmaceuticals and materials with novel opto-electronic properties. From its beginnings in the study of natural products, organic chemistry has evolved into a intellectual discipline which provides a rationale for the reactivity of organic molecules, from the smallest to the most complex. At the highest level of complexity it is concerned with the processes of life, and much of modern organic chemistry is about-biology -described and interpreted at the molecular level. This area, often called Bioorganic Chemistry, is a major commitment of the department. In particular, studies on the biosynthesis of natural products are proceeding at the enzyme level -backed up by the techniques of genetic engineering. The field also embraces studies on the specificity and stereochemistry of enzyme action, with a view to developing artificial catalysts for the synthesis and modification of biologically active compounds. The tailoring of molecular properties for particular applications (e.g. highly specific drugs which have maximal therapeutic value with a minimum of side effects), and the synthesis of novel organic structures for such purposes, is a major endeavour in modern organic chemistry. Several research groups are active in this area, developing and applying new methodology for controlling the stereochemistry of organic chemical reactions and for developing efficient catalytic chemistry. The design and synthesis of new molecular materials and polymers is a rapidly growing area of research. Organic semiconductors and dyes with unusual optical and electronic properties are needed for display technology, solar energy harvesting, communications and other applications.