The Potential of Pentagonal Building Blocks: From Giant Ring-shaped to Spherical Polyoxometalate Clusters

The deliberate construction of multifunctional compounds using the most elegant synthetic strategy possible, the one pot reaction, is one of the most challenging problems in contemporary chemistry.[1] Conceptually it is more straightforward to consider the synthesis in terms of successive steps of reaction and isolation, following the logic of retrosynthesis.[2] However it is obvious that the chances of success (synthesising such molecules on a reasonable time-scale and in good yield) using this approach decrease very rapidly indeed as the number of steps in the synthesis increase. A potentially powerful alternative to such an approach can be gained by observing the way in which nature overcomes this problem – by the exploitation of weak interactions and symmetrical complementarity in the assembly of massive architectures such as DNA, Viruses and proteins.[3] Nature, by carefully controlling the properties of the building blocks, is able to facilitate the ‘self-assembly’ as well as stepwise growth of such systems and thereby bypass the problems associated with the pure stepwise synthesis. The result is truly amazing, giving massive molecules with incredible functionality and molecules with the ability t