Synthesis,Assembly And Properties Of Chiral Amino Acid Porphyrin

Porphyrins are class of electron donor chromophores that are widely used as molecular materials.Their optical and electronic properties can be adjusted through the peripheral functionalization of the parent porphin ring and the combination of different metals.In recent years,scientists have made more and more explorations on the functional modification of porphyrin compounds.By understanding the performance of such compounds after specific modification,they can be better developed and used judiciously.It is worth mentioning that specifically designed chiral porphyrin compounds can be widely used as catalysts,sensors,and nonlinear optical(NLO)materials.In this paper,a variety of porphyrin compounds modified by different functional groups were designed and synthesized.The main research contents are as follows:(1)Anthracene ring was used as the functional linking group of chiral porphyrin compounds.Chiral alanine and phenylalanine were used as chiral excitation units.The corresponding chiral amino acid porphyrin monomer and its metal nickel manganese and zinc complexes were designed and the post-synthesis was achieved by anthracene [4 + 4] cycloaddition reaction,leading to the production of the corresponding chiral porphyrin dimer.Ultraviolet-visible spectroscopy(UV)and mass spectrometry were used to observe the changes in its structural stages.Circular dichroism(CD)and magnetic circular dichroism(MCD)were used to analyze the spectral properties before and after synthesis.In addition,the effect of metal porphyrin complex stability on postsynthesis was also explored.In a nut-shell,we successfully achieved a novel route designed by post-synthesis to obtain the target chiral porphyrin dimer.The limitation that the bridge center of the porphyrin dimer is a double bond group is broken,and the monocarboxylic acid group becomes the main body of the bridge,which provides a new idea for molecular design.(2)Using 2,2-biphthalic acid and 4,4-biphthalic acid as bridging groups,three metal nickel porphyrin dimers were synthesized and separated,including the cis and trans structure compounds of 2,2-biphthalic acid.In addition,using chiral alanine as the chiral excitation unit,4,4-biphenyl bridged chiral alanine porphyrin dimer was obtained.The structure was characterized by nuclear magnetic resonance spectroscopy,and the spectral differences between the three compounds were analyzed by ultravioletvisible spectroscopy(UV)and circular dichroism(CD).The relationship between chiral units and spatial conformation is explored,which provides a theoretical basis for the development and research of chiral molecules.(3)Using pyrene ring as the tail group,a series of chiral porphyrin derivatives were synthesized,and then composited with multi-walled carbon nanotubes respectively.The resulting material possessed nonlinear optical properties superior to multi-walled carbon nanotubes.The electron transfer in the compounding process was analyzed by fluorescence spectroscopy.The spectral properties of porphyrin derivatives with different chiral excitation groups were analyzed by ultraviolet-visible spectroscopy(UV)and circular dichroism chromatography(CD).The effects of chiral excitation groups and pyrene ring conjugated groups in porphyrin compounds on the optical properties of multi-walled carbon nanotube composites were investigated.The result obtained indicates the application of porphyrin compounds in materials is expanded and optimization direction for the properties of nonlinear optical materials is provided.(4)Using xanthene as a bridging group,chiral porphyrin dimers and their metal cobalt complexes with tryptophan chiral excitation group were prepared.The structure was characterized by nuclear magnetic resonance spectroscopy and its electrochemical hydrogen evolution performance and electrochemical impedance spectroscopy were tested under different aggregation states.Scanning electron microscopy was used to analyze the morphological characteristics of the electrocatalytic hydrogen evolution efficiency in the optimal aggregation state.The recrystallized nano-crystallite method provides a new route for the study of compound performance and increases the selectivity of chiral molecules in the way of enhancing electrocatalytic performance.