Supramolecular Synthesis via Integrative Self-Sorting

Generally speaking, complex function is based on complex structure. In the macroscopic world, devices and machines are assembled from many different components cooperating with each other to perform complex functions. The same holds true for most functional molecular assemblies in Nature. Understanding the organization principle underlying these assemblies could enable chemists to design more complex artificial assemblies functioning as molecular machines and smart materials.

During his PhD research, Wei Jiang proposed the strategy of integrative self-sorting by combining several well-known concepts in supramolecular chemistry – self-assembly, multivalency, templation, and self-sorting. This strategy incorporates simple self-sorting components into one well-defined supramolecular assemblies, thus provides a modular, programmable approach to access high-level structural complexity and diversity. With two sets of supramolecular binding motifs – one in water and one in organic solvent, he has successfully demonstrated the feasibility of this strategy. On the basis of the latter set, various assemblies have been constructed, showing that structural diversity can be readily accessed with this strategy.

Nevertheless, the high-level structural complexity and low symmetry of these integrative self-sorting assemblies impose great challenge on common analytic techniques. Although NMR spectroscopy can still be used for the characterization of the assemblies up to a certain level of complexity, tandem mass spectrometry turns out to be particularly useful to analyze the assemblies’ connectivities. In addition, through coupling a mixed-flow microreactor to electrospray ionization mass spectrometry, the formation kinetics of these assembles have also been studied. Detailed understanding of their formation kinetics enables the design of a streamlined formation pathway with which the thermodynamic products can be reached with high assembly efficiency.

In summary, the research described in this thesis provides a general strategy – integrative self-sorting – to non-covalently synthesize complex supramolecular assemblies, and thus lays the structural basis for achieving complex supramolecular functions.