Synthesis And Characterization Of Tetraarylcyclobutane Linked Perylene-porphyrin Dyad And Porphyrin Self-assemblies

Porphyrin have interesting attentiveness due to their exclusive photophysical and electrochemical properties,it can be changed by the substitution of porphyrin core and the insertion of different metals ions.These exclusive properties contain high photoluminescence,strong photostability,the great quantum yield of fluorescence,and admirable light harvesting.Perylene,on the other hand,is used as electron acceptors,due to their low LUMO and minor alteration energies in porphyrin-perylene dyad.This thesis focuses on the synthesis of perylene and porphyrin chromophores linked by h(?)t(?)r(?)arylethcne and its photodimer,and the porphyrin self-assemblies with styrylpyridine dimer.The designed new perylene-porphyrin dyad linked by a photocleavable photodimer of heteroarylethene.Upon the irradiation of UV light(254 nm),the photodimer will be quickly cleaved to two monomers.This photoreaction can be designed as a trigger to cleave the dyad into separated perylene and porphyrin moieties.The interaction between two chromophores will change from intramolecular to intermolecular interaction,which lead to the recovery of the quenched fluorescence of the perylene by porphyrin.The three dyads in this research are(1)perylene-dimer-perylene,(2)porphyrin-dimer-perylene,(3)and porphyrin-dimer-porphyrin.The structures of these compounds are confirmed by 1H NMR and 13C NMR spectroscopy.Based on these two chromophores which is linked with each other by tetraarylcyclobutane,their photophysical properties were also studied,such as UV-Vis absorption spectroscopy and fluorescence.In other hand,we also designed porphyrin based self-assemblies with styrylpyridine photodimers,two of them were unreported.All the prepared compounds are prepared according to the literature,the yield of the product is not same as the literature.Some of them have high yield then the literature while some of them is less.Unreported photodimers 1,2-di(4-formylphenyl)-3,4-di(4-pyridyl)cyclobutane and 1,3-di(4-formylphenyl)-2,4-di(4-pyridyl)cyclobutane were formed by the UV irradiation in the presence of HC1 aqueous solution,the light was used medium pressure mercury 300W lamp.For these unreported photodimers was fully characterized by 1H NMR,13C NMR,IR,and HRMS.The head to tail photodimers of bromostyrylpyridine and chlorostyrylpyridine were synthesized in acidic aqueous solution because the pyridine was protonized to form a salt and dissolved in the acidic aqueous solution.The phenyl ring is an electron-rich group and the pyridinium ring is electron-deficient group,and the interection between these two groups lead to the formation of a pair of monomers in a head to tail manner.The[2+2]photocycloaddition reaction is achieved upon UV irradiation.Coordination interaction was study between photodimers and zinc porphyrin,such as rctt-1,3-di(4-chlorophenyl)-2,4-di(4-pyridyl)cyclobutane,rctt-1,3-di(4-bromophenyl)-2,4-di(4-pyridyl)cyclobutane,and zinc tetra(butoxyphenyl)porphyrin.Coordination interaction was monitored by 1H NMR spectroscopy.The 2,6-position protons of the pyridine ring were shifted from 8.44 ppm to 4.00 ppm and 4.90 ppm which confirms strong coordination interaction between zinc tetrabutoxyphenylporphyrin and rctt-1,3-di(4-chlorophenyl)-2,4-di(4-pyridyl)cyclobutane.And it is similar that the rctt-1,3-di(4-bromophenyl)-2,4-di(4-pyridyl)cyclobutane is coordinated to zinc tetrabutoxyphenylporphyrin.