Macrocycles and complex three-dimensional structures comprising Pt(II) building blocks

Metalla-macrocycles and complex three-dimensional structures containing Pt(II) building blocks are becoming increasingly attractive and the focus of research due to their highly effective synthesis by supramolecular self-organization and templating processes, their enhanced stability in comparison to the analogous Pd(II) complexes and their attractive properties arising from their (multi)cyclic structures. In this comprehensive review, many aspects of Pt(II) macrocyclic structures are considered and the development of this exciting field is described from the beginning of the 1990s, covering literature until the middle of 2004. We have surveyed and organized the diverse data by first describing relevant Pt(II) building blocks, which are frequently used as a scaffold due to their defined angles and binding vectors. In an extensive second section, the various Pt(II) macrocycles are organized and described according to the mode of binding of the Pt(II) metal centres to the bridging ligands, most frequently Pt-N, Pt-C and Pt-P. Structures are summarized according to their molecular geometries-squares and rectangles, triangles, hexagons and cyclodimers. Very recent developments such as reactions and applications of these sophisticated molecular architectures are also taken into account. The third section describes even more complicated 2D compounds, 3D cage structures and topological architectures such as catenanes comprising Pt(II) centres, which are effectively formed by self-assembly processes. Interesting features such as controlled host-guest chemistry, selective molecular recognition and interesting material properties now come into range.