Supramolecular cubes

In 1998, Jim Thomas and co-workers at the University of Sheffield, UK, set out to prepare a self-assembling supramolecular cube by a combination of linear spacers, which would provide the cube edges, and pyramidal corners, which would constitute the vertices. Deconstruction of a cubic figure in this way reveals immediately that a ratio of eight corners to 12 edges is needed (Figure 10.24). 

Figure 10.24 (a) Components of a supramolecular cube, (b) Synthesis of a supramolecular cube. 

Roche S et al (1998) Self-assembly of a supramolecular cube. Chem Commun 1681-1682... 

A highly original aim, synthesizing a supramolecular cube, was realized by Thomas and co-workers [13] who linked metal corners with bifunctional, rigid, linear spacers. The complete the metals coordination environment the corners were capped with [9]ane-S3 macrocycles. There is a central cavity but it is too small to encapsulate molecules of the size of proteins or genetic material. 

Of course an icosahedron is not the only three dimensional design that can form a capsule. MacGillivray and Atwood proposed a structural classification for supramolecular assemblies based on the five Platonic and 13 Archimedean solids [21], The Platonic solids, illustrated in Fig. 3.10, are the tetrahedron, cube, octahedron, dodecahedron and icosahedron. 

The self-assembly of the supramolecular cube 27 from 20 components has been reported." Using nitromethane as a non-co-ordinating solvent, [Ru([9]ane-S3)(dimethyl sulfoxide)Cl2J was treated with 4,4-bipyridine in an 8 12 (namely 2 3) ratio and the reaction was monitored by NMR spectroscopy. The proposed... 

Self-assembly of a supramolecular cube, J. A. Thomas, S. Roche, C. Haslam, H. Adams and S. L. Heath Chem. Commun., 1998, 1681. 

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