From discrete metal complexes to supramolecular assembly, nanostructures and sensory functions

Recent works in our laboratory have shown that novel classes of light-absorbing and luminescent molecular materials could be assembled through the use of various metal ligand chromophoric building blocks. In this presentation, various design and synthetic strategies will be described. A number of these metal-ligand chromophoric complexes have been shown to display rich optical and luminescence behaviour. Correlations of the chromophoric and luminescence behaviour with the electronic and structural effects of the metal complexes have been made to elucidate their spectroscopic origins. These simple discrete metal complexes are found to undergo supramolecular assembly to give a variety of nanostructures and morphologies. By understanding the spectroscopic origin and the structure-property relationships, different approaches and assembly motifs have been employed to tune their electronic absorption and emission characteristics. Subtle changes in the microenvironment and nanostructured morphologies have led to drastic changes in both the electronic absorption and emission properties of these supramolecular assemblies. Explorations into the underlying factors that determine their spectroscopic properties and morphologies as well as their assembly mechanisms have provided new insights into the understanding of the interplay of the various intermolecular forces and interactions for the directed assembly of novel classes of metal-containing soft materials and hybrids. Through rational design and various strategies, these metal complexes may find potential applications and functions as efficient triplet emitters and as luminescence materials for chemosensing, molecular recognition and biological assays.