New Dendrimer Porphyrin - Perylene Molecular Array Synthesis, Characterization And Performance Study

Supramolecular chemistry is focus on the architecture and functionalization of molecular aggreagets which associated with weak enteractions.Supramolecular self-assembly has been one of the core branch of supramolecular chemistry,design,synthesis and self-assembly properties of organic molecules have been attract the attention of scientific community.Porphyrin and perylene diimide could be utilized in organic chemistry,material chemistry,photophysical chemistry and so on due to their excellent structural and functional features.Meanwhile,they can modified by molecular size,molecular shape and functional groups,often used as supramolecular building blocks.Five novel dendritic porphyrin-perylene molecule arrays were synthesized from tetraphenyl porphyrin,cyanuric tricholoride and 1,6,7, 12-tetrachloro-3,4,9,10-perylenetetracarboxylic dianhydride by divergent method,which porphyrin units serve as periphery groups, cyanuric tricholoride units as lingkers,perylene diimide unit as central core.The intermediate compounds and target molecule arrays was characterized by FT-IR and ¹H NMR.The conditions of synthesis were also discussed.The electronic structure of dendritic porphyrin-perylene molecule arrays 11,12,14,15,20 have been investigated by UV/Vis absorption spectra.The absorbtion spectra only exhibit porphyrin chromophore absorption,indicated the porphyrin and peryleneimide units have strong interaction in the ground state.Photo-induced energy transfer and electron transfer process of dendritic porphyrin-perylene molecule arrays 11,12,14,15,20 have been investigated by fluorescence spectra.Selectivity excited perylene diimide chromophore at 490 nm,molecule arrays almost only exhibt porphyrin emission,while perylene dimide emission has quenched significantly. This indicated efficient photo-induced energy transfer process from perylene diimide to porphyrin units in these molecule arrays.Selectivity excited porphyrin chromophore at 430 nm,molecule arrays almost only exhibt porphyrin emission,and the fluorescence quantum yield of porphyrin units was reduced contrast to the reference compounds TPP and ZnTPP.This indicated photo-induced electron transfer process from porphyrin units to perylene diimide unit in these molecule arrays.Supramolecular self-assemble property of dendritic porphyrin-perylene molecule arrays 11,12,14,15,20 have been investigated by UV/Vis absorption spectra and fluorescence spectra in CH₂Cl₂.The change of the absorbtion and fluorescence spectra in different concentration reveal the molecules was assembled with J-type aggregate.The morphology of the self-assembly was investigated by SEM.Molecule arrays exhibt hole-film structure in CH₂Cl₂,and honeycomb-film was obtained in 1×10^-4mol.L^-1 in CH₂Cl₂,this indicated concentration of the assembly affect the morphology of the aggregates remarkable.