Synthesis And Self-Assembly Of Boron Difuoride/Pt(Ⅱ)-Coordinated β-Diketonate Derivatives

β-Diketone compounds become a kind of important organic functional molecules due to its planar structure and π-conjugated nature upon coordonation,serving as a chelating ligand.This kind of compounds can form stable complexes with boron trifluoride or metal centers like Pt(II).Their molar absorption coefficient and photoluminescence the quantum yield increased significantly,and their photophysical properties are sensitive to chemical environmental changes,which is capable to obtain stimuli-responsive materials.Through structure modification,β-diketone compounds and its derivatives show the unique potential applications in organic semiconductor,OLED,solar battery,dye,biosensor,oxygen probe and other fields.Amphiphilic molecules have been formed to be convenient to molecular design due to their adjustable hydrophilic and hydrophobic groups.Using the structural characteristics and functional properties of β-diketonate compounds and their derivatives to realize the structural control and optimizing the performance in a variety of materials and components of molecular aggregation,however,are still the current important challenges in the field of study.Supramolecular assembly based on non-covalent forces provides a theoretical basis and method to solve this bottleneck problem.Therefore,this thesis focuses on the control of molecular structure,attempting to establish the structure-property relationship between self-assembled β-diketonate derivatives and their various photophysical and chemical properties.Changes in the microenvironment of the β-diketonate derivatives have been made to investigate the governing factors toward their photophysical properties and self-assembly properties.To achieve this goal,a series of β-diketone derivatives containing glycol chains and alkyl chains has been designed and synthesized.The B(Ⅲ)and platinum(Ⅱ)was introduced as the central atoms has been made.The self-assembly properties and structures in solution and the relationship with physical properties were studied.In first part of work,boron was introduced as a coordination atom,where the O-O bidentate chelation from difluoroboron β-diketonate can be obtained.Different numbers of hydrophobic alkyl chains and hydrophilic TEG chain are introduced to both ends of the π-system to form hydrophilicity-hydrophobicity separation.The hydrophobic interactions can be systematically changed by changing the number of chains.When the hydrophobic moiety is large enough,the compounds can be assembled in the well-soluble solvent of pure tetrahydrofuran(THF).When the hydrophobic moiety is not large enough,it is necessary to introduce water as a poorsoluble solvent to promotes its self-assembly behaviors.Meanwhile,the systematic variation of the hydrophobic interaction has led to changes in self-assembly mechanism.At the same time,the morphologies of the supramolecular assemblies have been formed to be altered.A subtle balance between the hydrophobic and hydrophilic moieties has been formed to achieve a more regular nanostructere.When the hydrophobicity is too strong,the nanostructures of the assembly will be loosely packed.When the hydrophilicity is too strong,the nanostructures of the assembly will also be irregular,and even the layer structure cannot be retained obtain a spherical aggregate.In this work,the role of hydrophobic interaction in amphiphilic boron difluoride β-diketone compounds was investigated.The relationship between hydrophilic and hydrophobic interaction on the assembly structure and photophysical properties was investigated.The factors governing the balance between the morphology of the assembly and the hydrophobic interaction and the correlation between the structure of the compound have been elucidated.In second part of work,based on the previous chapter,the thiophene group is introduced to the amphiphilic β-diketonate compounds containing three hydrophobic alkyl chains and hydrophilic TEG chains to enable the extension of the compound,objective studied the effects of π-π interactions on this class of compound.The introduction of thiophene has been formed to show insignificant changes the to hydrophobic interactions of the compound,but it will effectively increase the π-system of the compound,which also is formed to change the self-assembly mechanism and the morphologies of the supramolecular aggregation.When the subtle balance of π-πinteraction is reached,the nanostructure can be more regular.Their layer spacing also becomes large with the introduction of thiophene.In this work,the role of π-πinteraction in amphiphilic boron difluoride β-diketone compounds was explored.The self-assembly of these compounds was investigated,and the morphology of the assembly and their dynamic parameters between the assembly mechanism and π-πinteraction of this class of thiophene-containing β-diketonate compounds have been obtained.In third part of work,square-planar d8 platinum(Ⅱ)metal center was introduced to form phenylpyridine-Pt(Ⅱ)-diketone(PPy-Pt-DK)complexes.Different chains were introduced to different ligands to hardly obtain two phase separation.Meanwhile,thiophene group were introduced.It is difficult to form intramolecular charge transfer because of the absence of strong electron withdrawing inductive effect of the fluoride.After two thiophenes were introduced,the hydrophobicity is greatly enhanced.And the supramolecular aggregate can be formed in the pure THF.Since it is difficult to form a two-phase separation of hydrophobicity and hydrophilicity.The bond between the thiophene group and diketone can be rotated,which can make the complexes more easily self-assembly to form a more stable,a larger aggregate of a larger surface area.Similarly,the two-phase separation of hydrophobicity and hydrophilicity can also affect the stacking method to release more energy to obtain more stable assemblies.In this work,the role of metai-metal interaction,π-π interaction and stacking effect in the phenylpyridine-Pt(II)-diketone complexes was explored.The self-assembly stacking mode of these compounds was investigated,and the correlation between the molecular configuration and the degree of hydrophilic and hydrophobic phase separation and the assembly shape was found.The understanding of the degree of hydrophilic and hydrophobic phase separation and the influence of the stacking mode on the complex assembly were obtained.Therefore,we use β-diketonate ligands have been used as the base unit,with the incorporation of alkyl chain and triethylene glycol chain that can regulate the hydrophilic and hydrophobic properties,thiophene group that can regulate the πinteraction,and Pt(Ⅱ)metal center as the central atom to extend the conjugated structure,so as to control the degree of hydrophilic and hydrophobic two-phase separation of the molecule.The molecular structure can be systematically adjusted to affect the selfassembly process,mechanism,stacking mode and specific morphology of orderly spontaneous aggregation in mixed solvents.The rule of the equilibrium between the morphology of the assembly and different non-covalent forces is found,and the law of the change of the equilibrium and assembly mechanism of π-π interaction is found.The relationship between hydrophilic and hydrophobic two-phase separation of compound structure and assembly shape was found.The relationship between the morphology of the assembly and the equilibrium of different non-covalent forces was established.The results obtained in these studies not only enrich the self-assembly system of amphiphilic molecules in solution,but also provide a new understanding for the rational design of β-diketone-containing luminescent complexes.