Research Of Fluorescent Supramolecular Assemblies Based On Platinum(â…¡) Alkyne Complexes

Supramolecular assemblies is a novel class of assemblies with well-defined structures which are formed with a large number of monomer units by highly oriented and reversible non-covalent interactions, including H-bonding, host-guest interaction, metal-ligand interaction, π-π stacking and hydrophobic interaction. Inspired by the nature, construction of supramolecular assemlies through various of non-covalent interactions is becoming a promising way in polymer science, in which the discovery of new building blocks and the application of their specific functions is a important step to realize the goal.Platinum(II) acetylide unit is considered as an excellent building block in supramolecular assemlies, because its square planar configuration makes it possible to couple with other non-covalent bonds effectively and its unsaturated coordination leads to the favourable optical property. Based on the former study of our group on platinum(II) acetylide unit, in this dissertation we integrate benzothiadiazole unit between the two platinum acetylide moieties and bottom-to-up self-assembly into a novel class of fluorescent supramolecular assemblies, comprising two parts:In the first part we introduce amide and oligo(ethylene glycol) segments to form a bolaamphiphilic monomer, which can self-assembly into fluorescent supramolecular assemblies driven by H-bonding and hydrophobic interacion in aqueous solution. We investigated critical aggregates concentration(CAC) through Nile Red encapsulation experiments and the major driving force for self-assembly in water and n-butanol was acquired by means of isothermal titration calorimetry (ITC) measurements. Meanwhile, the cell staining experiments demonstrated that resulting fluorescent supramolecular assemblies could serve as novel candidates for fluorescence imaging applications.In the second part we introduce terpyridyl units on both ends of the monomer, which can coordinate with transition metal ions Zn2+, Fe2+ and then aggregate into fluorescent supramolecular assemblies. Then we increase the conjugated length of the chromophore to induce donor-accepor effect between these two different chromophores, hoping that energy transform can be observed in the supramolecular assemblies with mutiple chromophores formed by their mixture.