Book excerpt: Copper(I) Complexes of Phosphines, Functionalized Phosphines and Phosphorus Heterocycles is a comprehensive guide to one of the most widely used and extensively studied metals: copper. The numerous practical applications of copper compounds are discussed, including homogeneous and heterogeneous catalysis and their use as fungicides, pesticides, pigments for paints, resins and glasses, and in high-temperature superconductors. The remarkable structural flexibility of simple copper(I) complexes, such as cuprous halides is covered, including numerous structural motifs that, when combined with different ligand systems, exhibit linear, trigonal planar or tetrahedral geometries. This work is an essential reference for inorganic and coordination chemists, as well as researchers working on catalysis, anticancer reagents, luminescence, fluorescence and photophysical aspects. - Discusses the properties of copper and similarities to noble metals, such as their corrosion resistance, high thermal and electrical conductivity and rich coordination chemistry - Includes the copper(I) coordination chemistry of tertiary phosphines, bisphosphines and phosphines containing other donor atoms and their potential application in catalysis, biosystems and photochemical areas - Features a discussion of the rich photochemistry exhibited by some mixed-ligand copper(I) complexes (phosphines with heteroaromatic ligands) which can exhibit coprophilic interactions, photoluminescence and thermochromic properties