Controlled Assembly And Functionality Of Organoplatinum(?)-based Supramolecular Systems

Supramolecular assembly,which aggregates components into large and regulare systems,is a ubiquitous process that occurs at all levels in nature:from the extremely large,such as organisms,to the extremely small entities,such as molecules.Inspired by nature,developing artificial supramolecular self-assembly system via elaborately manipulating non-covalent interaction has emerged as an important and elegant way to create novel and functional materials.Hence,the construction and functionalization of the supramolecular assemblies based on various building blocks has been vigorously developed in the past few decades.The d8 platinum(?)complexes,noted for coordinate-unsaturation and square-planar geometry,has received wide concern to construct function supramolecular assemblies because of various molecular structure as well as fascinating properties.This dissertation,comprising four parts,focuses on the construction and potential optically function of various supramolecular assemblies based on platinum(?)complexes.In the first part,we designed and synthesized a monodentate type anthracene-platinum(?)acetylide monomer,which is prone to form 1D helical self-assembly via the cooperative nucleation-elongation mechanism.Upon replacing chiral amides unit in monomer with chiral esters,the relationship between molecular structures(hydrogen bonds et.al)and supramolecular assembly behaviors was further studied.Then,we explored the circularly polarized luminescence behavior of supramolecular assembly by combining the chirality and luminescence.On this basis,the fluorescence resonance energy transfer(FRET)process was achieved in a two-component co-assembly strategy after introducing another similar acceptor.This strategy successfully regulate the circularly polarized luminescence region.Comparing with monodentate platinum(?)acetylene compounds,multidentate cyclometalated platinum(?)complexes have rich photophysical properties.Hence,we constructed muti-component supramolecular assemblies-organic metal supramolecular gels,which used the cyclometalated platinum(?)complexes as the basic building blocks in the second part.These organic gels were achieved in nonpolar solvents via synergistic non-covalent driving forces such as Pt(II)-Pt(II)metal-metal and donor/receptor interactions.Then,we investigated the mechanism of gel formation through exploring one-component and two-component assembly behaviors.On this basis,the properties of two-component supramolecular metal gels were further regulated by variation of the relevant parameters,such as the molecule structure and solvent of gelation.This work provides a new idea for the construction and development of soft materials.The aforementioned assemblies have the excellent optical properties,but they are always unstable,which can only exist stably in nonpolar solvent.That is because the relatively weak non-covalent binding ability among the building blocks.It is a feasiable way to strengthen the non-covalent interaction by using rigid preorganization effect.Bsed on above research,we introduced the cyclometalated platimun(?)complexes into the molecular tweezers and constructed a series of supramolecular assemblies in the third part.On this basis,we further achieved the construction of hierarchical suapramolecular assembly—two topological(linear and cross-linked)supramolecular polymers—by using tripyriridine-platinum(?)-based molecular tweezers.In the following experiments,we also investigated the near-infrared luminescence behavior and photosensitivity of platinum(?)-based supramolecular polymers.It is noted that aforementioned assemblies are all in the thermodynamically stable state.In the last part,we constructed a self-complexation type assembly system based on cyclometalated platimun(?)tweezers with preorganization effect.Under the assistance of Cu(I)ions,such assemblies were lied in non-equilibrium kinetically trapped state.Then,we analyzed the formation mechanism of the non-equilibrium system by in-depth characterations,such as rational design in molecular structure and monitoring the conversion process from non-equilibrium to equilibrium state.Considering the existence of non-covalent ?-?/Pt-Pt interaction,we further explored the red/near-infrared light photothermal converation properties of discrete Pt(II)-based assemblies.This work fully bridged the relationship between structure,assembly and function.