Synergistic Multicomponent Self-Assembly Based On N-Terminal Aromatic Amino Acids

Amino acid is one of the most important biological molecules with the advantages of broad resource,easy to modify,good biocompatibility and biodegradability.It has shown potential application in many fields.Modification the amino acids with aromatic groups can endow them fantastic properties,such as stimulus responsiveness,charge transfer and chiral optics.N-terminal Aromatic Amino Acids could coassemble with achiral functional organic small molecules via noncovalent orthogonal forces to obtain smart materials with multiple stimuli responsiveness.During the process of co-assembly,molecular chirality could transfer between amino acids and the supramolecular chirality can transfer between different components,which has enriched the application of N-terminated Aromatic Amino Acids in asymmetric catalysis,selective adsorption and separation,biochemical sensors,three-dimensional and even four-dimensional materials.In this thesis,we investigated a series of N-terminated Aromatic Amino Acids and their supramolecular chirality.We also systematically studied the relationship between molecular structure and chirality.Multicomponent supramolecular chiral system has been achieved through the coassembly of N-terminated Aromatic Amino Acids with achiral small molecules via noncovalent interactions.Circularly polarized light absorption and emission of the supramolecular chiral system could be accurate controlled.The main contents of this thesis as follows:We designed and fabricated 8 kinds of amide acid derivatives which were modified by anthracene.Supramolecular chirality in the single crystal structure was analyzed via the asymmetric stack of anthracene groups.Powder X-ray diffraction(XRD),circular dichroism(CD),circularly polarized luminescence(CPL)and theoretical calculation were employed to characterize those molecules.There supramolecular chirality in solid-states could divide into three categories:1)hydrogen bond induced 21 staking model(glycine,valine and glutamic acid derivatives);2)hydrogen bond induced 31 staking model(tyrosine and alanine derivatives);3)Weak force from aromatic group induced 21 staking model(phenylalanine,phenylglycine and serine derivatives).We found their chiral optical properties including CD spectra and CPL could be accurate predicted from their molecular structures.White light material whose CIE coordinates locate at(0.34,0.33)was obtained after the introduction of new composition.L-/D-phenylglycine and L-/D-alanine derivatives modified via pyrene were synthesized.Multicomponent supramolecular assembly was formed based on amino acid derivative,electron-deficient tetracyanoquinodimethane derivative(TCNQ)and melamine via the charge transfer and hydrogen bond interactions.Physical and chemical properties of various assemblies were studied vai Fourier transform infrared spectroscopy(FT-IR),XRD,electron microscopy,CD and rheological analysis.Alanine derivative occured self-sorting in multicomponent system,yet phenylglycine derivative coassembled with TCNQ and melamine could form helical microtubes.And we investigated the mechanism of chiral generation.Phenylalanine and valine derivatives(Phe and Val)which modified by pyrene were fabricated.Coassemble behaviors with benzimidazole derivatives(TBIB)or 1,2,4,5 tetracyanobenzene(TCNB)were investigated through modularizing those small molecules with different function.The assemblies were characterized by FT-IR,XRD,transmission electron microscopy(TEM),CD and CPL.The coassembly could emits cold white light when the molar ratio of Val to TCNB is 3:0.05.Three-component hydrogel with chiral optical activity were obtained via the synergistic effect.The hydrogel showed well rheological properties.The generation of supramolecular chiral structure in the hydrogel was studied.