The Synthesis And Catalytic Application Of Multi-Fuctional Porphrin/Ionic Liquid Based Porous Organic Polymers

Owing to the growing concern on environmental and economic problems,it is of great importance to develop more efficient and sustainable chemical industry.In this regard,the utilization of solar energy and the chemical transformation of carbon dioxide?CO₂?are getting momentum.Herein,novel porphyrin/ionic liquid based organic porous polymers?Por-POP-X;X=Cl,Br,I,OAc,Tf₂N?and the corresponding porphyrin magnesium/ionic liquid based organic porous polymers?Por-POP-Mg-X?were facilely synthesized and explored as catalysts for photoinduced electron transfer-reversible addition-fragmentation chain transfer?PET-RAFT?polymerization and the coupling reaction between epoxides and CO₂,respectively.The details are listed as follows:1.A series of Por-POP-X were synthesized in a one-pot process by using the Debus-Radziszewski“click”reaction,and then explored as catalysts for PET-RAFT polymerization.Owing to the conjugated skeleton consist of porphyrins and imidazoles,Por-POP-X displayed 2D lamellar structure though the?-?stacking reaction.Por-POP-OAc has strong absorption within the wavelength range of 200-900 nm and the strongest absorption at 442nm.It displayed high catalytic activity and well-controlled manner for the PEF-RAFT polymerization of vinyl monomers such as methyl methacrylate?MMA?and dimethyl acrylamide?DMAA?under white light or blue light.For example,a monomer conversion of83%could be obtained within 2 h under 5.1 mW/cm² blue light for the PET-RAFT polymerization of DMAA at room temperature?PDI=1.11?.We demonstrated that the polymerization could be temporally controlled by turning on/off the light.Moreover,as a metal-free catalyst,Por-POP-OAc can effectively avoid metal contamination and coloration.2.Started from Por-POP-X and MgBr₂,Por-POP-Mg-X were synthesized and explored as catalysts for the coupling reaction between epoxides and CO₂.In addition to the synergistic effect between magnesium porphyrin and the anionic part of the ionic liquid moieties?X^-?for the ring-opening of epoxides,the imidazoliums are effective for the absorption and activation of CO₂.In this regard,Por-POP-Mg-X showed high catalytic activity for the coupling reaction between epoxides and CO₂ without addition of cocatalysts.The catalytic activity was found to first increase and then decrease with CO₂ pressure,while it steadily increased with reaction temperature.Under an optimized reaction condition?150?,3 MPa CO₂?,both epoxy chloropropane and bromine epoxy propane can be fully converted to the corresponding cyclic carbonates within 4 h.In addition,the recycling of catalysts could be achieved by simple filtration and no obvious decrease of catalytic activity was observed after5 times recycling for Por-POP-Mg-Br.