Self-assembly using reversible metal-ligand interactions has provided efficient routes to numerous spectacular, discrete supramolecular structures, many of which exist in the nanoscale regime. We have developed a design strategy for using the unusual coordination chemistry of main group ions as a directing element in self–assembly reactions to form three-dimensional, multinuclear supramolecular assemblies. For example, the Group 15-thiolates feature an unusual trigonal pyramidal coordination geometry. This motif can be used in metal-ligand self-assembly to synthesize a series of E2L3 “cryptands”, E3L2 macrobicycles, and E2L2 macrocycles (E=As, Sb) from ECl3 and thiol ligands. Cryptands featuring the heavier Group 15 elements can be “transmetalated” to form the corresponding lighter E2L3 cryptand, which has enabled synthesis of a P2L3 cryptand. We have also shown that these main group assemblies are quite stable to air, moisture, acid and base; however, they react cleanly with mild oxidizing agents to yield discrete disulfide macrocycles and (hetero)cyclophanes. The scope of this reactivity is explored, showing that the process can efficiently prepare a variety of known and new 2D and 3D cyclophanes and heterocyclophanes in remarkably efficient reactions. Progress toward a new three-dimensional, unsaturated and fully conjugated tetrahedral cyclophane will be described.

Exploring reactivity in self-assembled main group coordination clusters: A new route to cyclophanes?

251st National Meeting (2016)

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