Assembled Metal Complexes and Their Functions

In recent interdisciplinary research, there has been an increasing interest in assembled metal complexes, in which metal centres are deliberately integrated using a variety of techniques for different purposes, in particular to solve problems of importance to mankind, such as material and energy transformations. This chapter will formally classify assembled metal complexes in a way that is easy to understand for the beginner, with respect to the following aspects: (1) those in which the accumulation of metal centres is constructed via metal–metal bonds (intermetallic bonds) or via the use of linker ligands (bridging ligands) without metal–metal bonds, (2) those in which the accumulation of metal centres is discrete and molecular or those in which the accumulation of metal centres is crystalline with infinite periodicity, and (3) those with one-dimensional (1D), two-dimensional (2D) or three-dimensional (3D) arrangements of metal centres. The particular importance of 3D assembled systems are explained for supramolecular metal complexes and porous coordination polymers or metal–organic frameworks, which are formed by the accumulation of metal centres with suitably designed linker ligands using strategic self-assembly methods, and their applications are also explained with respect to recent topics in relation to giant supramolecular cages and precisely designed robust 3D pore networks.