Synthesis,assembly And Photocatalysis Performance Of Octakis(6-imidazolyl Hexylthio) Porphyrazine

Porphyrin is a kind of macrocyclic compound existing in the nature.Its metal complex has great similarity with cytochromes P450 in structure and function.As a ramification of porphyrin,porphyrazine is a kind of green and efficient catalyst owning the same compact macrocyclic structure and delocalized conjugated ?-electronic system as porphyrin so that it can simulate cytochromes P450 who can degrade organic pollutant under a mild condition.Numerous researches indicated that porphyrazines have excellent photocatalytic performance,but most porphyrazines have limitation in application because of their poor solubility.Another reason limited the application is that the porphyrazines usually uneasy to be dispersed in the heterocatalysis and difficult to be recycled in the homogeneous catalysis.To improve the solubility of the porphyrazine,the well water solubility 2,3,7,8,12,13,17,18-Octakis(6-imidazolyl hexylthio)porphyrazine(H2Pz(SHe-Im)8)was synthesized in a more efficient way.To solve the probelm of dispersion and recycle of the catalyst in the reaction,the H2Pz(SHe-Im)8 was reacted with Pd Cl2 to self-assembly form easily dispersed products with different morphology.Then the aerobic oxidation of phenycarbinol was catalyzed by the self-assembly products as catalyst under a green condition of O2 as oxidant and H2 O as solvent.The main works in this paper can be summarized as follows:(1)The magnesium octakis(6-imidazolyl hexylthio)porphyrazine(Mg Pz(SHe-Im)8)was synthesized form the precursor using magnesium template method,then demetallized using trifluoroacetic acid(TFA)to get the ultimate product with a productivity of 6.84%.Afterwards the metal(Fe2+,Mn2+,Zn2+ and Co2+)complexes of H2Pz(SHe-Im)8,including Fe Pz(SHe-Im)8,Mn Pz(SHe-Im)8,Zn Pz(SHe-Im)8,Co Pz(SHe-Im)8,were synthesised.Meanwhile,all compounds were characterized by UV-vis,1H NMR and Maldi-TOF MS.(2)The H2Pz(SHe-Im)8 and Pd Cl2 were assembled under different conditions:(1)At various molar ratio between H2Pz(SHe-Im)8 and Pd Cl2.(2)In the different solvent.The molar ratio 1:4 between of H2Pz(SHe-Im)8 and Pd Cl2 was at last chosen and self-assembled in H2 O to form porous and chain-like nanostructure,whose molecular formula is H2Pz(SHe-Im)8·4Pd Cl2 and in short PSSW.The characterization of IR,EDS,EDS-MAP and XPS for PSSW showed Pd2+ to coordinate with the centre and the peripheric imidazole of porphyrazine ring,and dispersed at everywhere of the PSSW.And formation mechanism of the PSSW was explored to find the assembled product formed from slices or chips to little balls,and then turned to chain-like structure,finally obtained the PSSW.(3)Used on PSSW as catalyst,its photocatalytic activity was studied in the oxidation of phenylcarbinol.(1)The influence of temperature,oxygen pressure,illumination and loading of catalyst on its photocatalytic activity were mainly studied.And then its repeatability was studied.Under the condition of 120°C,a oxygen pressure of 10 atm,a light energy density of 0.583 W/cm2 and a 1:100 molar ratio betweem catalyst and substrate,the conversion of phenylcarbinol got to 78.81%,and the selectivity of benzaldehyde and benzoic acid are 45.55% and 36.20% respectively.(2)Using 2-Chlorobenzyl alcohol,2-Methylbenzyl alcohol,2-Methoxybenzyl alcohol,3-Methoxybenzyl alcohol,4-Methoxybenzyl alcohol as substrate respectively to study the photocatalysis performance of PSSW.The better conversions were obtained for these extended alcohols,the highest of which is 87.19% when using 4-Methoxybenzyl alcohol as substrate.