The Synthesis And Optical Properties Of β-alkynylpyridine Tetraphenylporphyrin Derivatives

Porphyrins and their derivatives are a class of macrocyclic compounds with good conjugation.Due to their unique properties,they are widely used in optoelectronics,biology,medicine,environment,etc.,while diporphyrin compounds have more than monoporphyrin compounds.More excellent performance has become a hot topic in research.In this paper,the method of synthesizing diporphyrin with pyridine derivative as bridging group was studied.The β-alkynylpyridine tetraphenylporphyrin derivative was synthesized by Sonogashira coupling,and its optical properties were studied.A total of 25 compounds were synthesized in this subject,10 of which had not been reported.There structures were characterized by 1H NMR,13 C NMR,MS,etc.to determine the structure,and there UV and fluorescence spectra of the new compounds were studied,their molar extinction coefficient was determined.Part 1: Synthesis of pyridine bridging groupsWe synthesized a series of pyridine derivatives by using 2,6-dibromopyridine and 2,5-dibromopyridine as raw materialswith coupling reaction.Part 2:Synthesis of β-alkynylpyridinyl TPPderivativesand attempt of synthesis of diporphyrinyl pryidineWe have linked the β-activated TPP to different bond bridges through a coupling reaction,and tried a number of different conditions to still not reach pyridine derivatives with two porphyrinyl,but obtained a series of monosubstituted β-pyridinylalkynyl TPP derivative.A series of free base porphyrin compounds were obtained by demetallization of concentrated sulfuric acid.Part 3:Preliminary Study on Optical Properties of β-Alkynylpyridine Tetraphenylporphyrin DerivativesThe UV-visible spectrum of porphyrins has two absorption bands,Soret band(B band)and Q band.B band has high absorbance,which is caused by π→π*(a2u→eg*)of porphyrin ring,Q band Relatively weak,produced by π→π*(a1u→eg*),the change in conjugate will cause both bands to change.Porphyrin is a special compound with double fluorescence behavior.We determined the UV and fluorescence spectra of the obtained β-alkynylpyridine tetraphenylporphyrin derivative,and studied its optical properties.