Synthesis And Characterization Of Chiral Amino Acid Bridged Porphyrin Dimers And Polymers

In the past two decades,covalently linked polyporphyrin arrays have attracted much attention,such as artificial photosynthetic systems,molecular lines,sensors,and nonlinear optical?NLO?devices.Among them,?-?,meso-meso,and meso-?triple fusion polyporphyrins have prominent properties,including large?-electron conjugates and extremely low HOMO-LUMO?highest occupied/lowest unoccupied molecular orbital?gaps.It has special significance.Chirality,on the other hand,is widespread and fascinating in nature,and has been a constant focus of research in the pharmaceutical,food and synthetic chemistry industries.During the research of porphyrins,scientists discovered an important branch of chiral porphyrins,but the current research on chiral porphyrins mainly focused on chiral porphyrin monomers.The synthesis and application researches started over decades,but the chiral porphyrin monomers,via different bridging groups,such as xanthene dicarboxylic acid,used to prepare the chiral amino acid polymer bridged by flexible amide bonds has not yet seen in-depth reports.In this paper,we first synthesized the oxaza bridges with xanthene dicarboxylic acid as the bridging unit and chiral alanine,chiral phenylalanine and chiral tryptophan as chiral amino acid raw materials.A total of six amino acid porphyrin dimers were synthesized in a trichloromethane?CHCl₃?solvent using chiral amino acid porphyrin dimer,free base and zinc metal acetate as raw materials to obtain zinc?II?-centered metal ions.This produced 6 kinds of chiral amino acid porphyrin dimer metal zinc?II?complexes.The chiral amino acid porphyrin dimer and chiral amino acid porphyrin dimer zinc metal?II?complexes were characterized by means of mass spectrometry and¹H NMR spectroscopy.UV-vis spectra?UV?and magnetic circular dichroism?MCD?were used to investigate the spectral properties of the chiral amino acid porphyrin dimer in CH₂Cl₂.SEM was used to study the aggregation state of chiral amino acid porphyrin dimer and the construction of chiral porphyrin dimer low-dimensional carbon material.The electronic structure of the chiral amino acid porphyrin dimer was studied using TD-DFT theory.Overall,based on these test methods,the effect of chiral amino acid species and chirality changes on the electronic structure and spectral properties of the porphyrin dimer as a whole in the flexible amide bridged dimer was studied,and the use of chirality was successful.Changes in the amino acid substituents regulate the structure of the low-dimensional carbon material constructed by the porphyrin dimer.Afterwards,isophthalic acid and terephthalic acid were selected as bridging groups,and the chiral amino acids were unchanged.Four chiral porphyrin dimers were prepared.The chiral amino acid porphyrin dimers were characterized by means of mass spectrometry and¹H NMR spectroscopy.UV-vis spectra?UV?and magnetic circular dichroism?MCD?were used to investigate the spectral properties of the chiral amino acid porphyrin dimer in CH₂Cl₂.This helped to understand the effect of chiral amino acid substitutions on the electronic structure and optical properties of the chiral amino acid porphyrin dimer.Taking into account the synthesis of dimers,this article also conceived whether the chiral amino acid porphyrin dimer extended to chiral amino acid porphyrin polymer.Therefore,a tetracarboxylic porphyrin was prepared as a bridging group,chiral alanine,chiral phenylalanine and chiral tryptophan were selected as chiral amino acid raw materials to prepare chiral amino acid porphyrin polymer Nickel?II?complexes.It was synthesized in 6 cases and the structure of the obtained complexes of nickel?II?complexes with chiral amino acid porphyrins was characterized by means of mass spectrometry and elemental analysis.The spectral properties of the chiral amino acid porphyrin multimer in CH₂Cl₂ were investigated by UV-Vis and UV circular dichroism?MCD?.In order to study the properties of the chiral amino acid porphyrin multimer and the change of the chiral amino acid substitution position,the electronic structure and optical properties of the chiral amino acid porphyrin multimer were studied.Then the chiral amino acids with photoactive groups were prepared by introducing the photoreactive group 9-guanidine formic acid as the bridging group and the chiral alanine,chiral phenylalanine and chiral amino acid as raw materials.Morpholine monomer in 4 cases.A chiral porphyrin dimer having a photoactive group is obtained by irradiation of a toluene solution of the chiral porphyrin monomer with a specific wavelength of ultraviolet light.The structures of the chiral amino acid porphyrins bonded by photoactive groups were characterized by means of¹H NMR.The spectral properties of the photoactive group-bonded chiral amino acid porphyrin dimer in CH2Cl2 were investigated by UV-Vis and UV circular dichroism?MCD?.In order to study the change of the properties of the photoactive group-bonded chiral amino acid porphyrin monomers before and after polymerization,the effects of chiral amino acid species on the electronic structure and optical properties of the chiral amino acid porphyrins were studied.At the end of this paper,5-?4-amino?phenyl-10,15,20-triphenylporphyrin was used as starting material and oxindoledicarboxylic acid as bridging group to prepare flexible amide bond bridged porphyrin dimer.The porphyrin dimer was reacted with zinc acetate dihydrate to prepare a porphyrin dimer metallic zinc?II?complex.The chiral amino acid porphyrin dimers were characterized by means of mass spectrometry and¹H NMR spectroscopy.UV spectroscopy?UV?and magnetic circular dichroism?MCD?were used to investigate the spectroscopic changes of chiral diamine recognition in chiral amino acid porphyrin dimers in CH₂Cl₂.