There has been enormous progress in our understanding of molybdenum and tungsten enzymes and relevant inorganic complexes of molybdenum and tungsten over the past twenty years. This set of three books provides a timely and comprehensive overview of the field and documents the latest research. The first volume focusses on the enzymes themselves, and discusses active sites and substrate channels of relevant proteins. The second volume covers the inorganic complexes that model the structures and reactivity of the active sites of each major group of molybdenum and tungsten enzymes. Special attention is given to synthetic strategies, reaction mechanism and chemical kinetics of these systems. In the final volume, spectroscopic and computational methods that have been applied to both enzymes and model compounds are explored with an emphasis on how these studies have been used to reveal critical components of enzyme mechanisms. Each book begins with an introductory overview that sets the three thematic areas of each book into proper context. Written by leading experts, this set of books will be a valuable reference to workers both inside and outside the field, including graduate students and young investigators interested in developing new research programs in this area.