Preparation Of Porous Organic Polyporphyrin And Its Application In Photo-induced Oxidation

A library of cross-linked poly-porphyrins with porous and network structures were prepared via the Sonogashira polymerization method to address the issues of the porphyrin monomers in separation,recycling and purification during the photocatalytic process.Two types of porphyrin monomers（dibromodiacetylenic porphyrin and tetrabromoporphyrin）were designed and the porphyrin-based porous organic polymer（PPOP-1）was obtained through self-polymerization of dibromodiacetylenic porphyrin.Four other polyporphyrins were obtained through the copolymerization of tetrabromoporphyrin and various linkers containing dialkynes.The surface morphology and pore structures of the polymers are characterized by scanning electron microscopy and physical adsorption.All of the polyporphyrins have a uniform ellipsoidal shape with a diameter of 0.3-0.5μm.All five polymers showed typical type III adsorption isotherms and strong adsorption of P1 at low pressure（P/P0<0.1）.The pore diameters of the polyporphyrins are all about 1 nm,and the specific surface areas are38.484,12.494,10.880,19.858 and 19.462 m²g^-1,respectively,the specific surface area of PPOP-1 is significantly larger than that of co-polymerized porphyrin,and its singlet oxygen quantum yield is the highest of all.Using PPOPs as a metal-free heterogeneous photocatalyst,the aerobic oxidation of dibenzylamine and its derivatives was induced by visible light,which proved that PPOPs have good catalytic activity for the oxidation of carbon-nitrogen bonds.Using PPOP-1 as a catalyst to catalyze the aerobic oxidation of dibenzylamine,the conversion rate of the system has reached 99%after 8 h,and the catalytic activity is the highest.After five cycles of catalyzing the oxidation of dibenzylamine,the catalytic activity of PPOP-1 basically did not decrease,which confirmed that polyporphyrin has good cycle catalytic performance.The same catalyst was used to induce the aerobic oxidation of bisamino thioketal,bishydroxy thioketal,diphenyl sulfide,and dibenzyl sulfide through visible light,which confirmed that the oxidation of carbon-sulfur bonds of PPOPs also has good catalytic activity.