This series of short texts provides accessible accounts of a range of essential topics in chemistry. Written with the needs of the student in mind, the Oxford Chemistry Primers offer just the right level of detail for undergraduate study, and will be invaluable as a source of material commonly presented in lecture courses yet not adequately covered in existing texts. All the basic principles and facts in a particular area are presented in a clear and straightforward style, to produce concise yet comprehensive accounts of topics covered in both core and specialist courses. The interaction of transition metals with unsaturated organic molecules has led to fundamental insights in the nature of the chemical bond which, in turn, have provided the basis of important present-day applications such as transition metal mediated synthesis or homogeneous and heterogeneous catalysis. This slim volume outlines the chemistry and discusses the bonding in some of the most important classes of organometallic compounds: the complexes of transition metals with [pi]-ligands such as alkenes, alkynes, arenes, and cyclopentadienyl and allyl ligands. The material covered follows on from Organometallics 1 which covers the chemistry of complexes with metal-carbon [sigma]-bonds. Synthetic and reactivity aspects of each class of compounds are illustrated with pertinent examples from the recent chemical literature. Highlighted excursions relate the fundamental chemistry to current synthetic or catalytic applications.