Synthesis And Properties Of Novel Carbazyl Substitute Porphyrin And Its Metal Complexes

Porphyrins are a kind of18π electrons macro-cyclic conjugated specialcompounds. They have good properties in light, electricity and magnetism. In recentyears, more and more scientists have researched in many aspects of porphyrins.Porphyrins have been applied in many fields, such as material science, iatrology,analysis chemistry, polymer chemistry, geochemistry and biochemistry, et al.Over the past decade, sensors and sense technology and have been greatlydeveloped and applied, luminescence-based optical oxygen sensors have been ofwidespread interest for their high sensitivity and selectivity. It has been demonstratedthat mesoporous silicas and transition metalloporphyrins were the excellent supportfor developing luminescence-based optical oxygen materials. In recent years, oxygensensing materials based on porphyrin complexes assembled in mesoporous silica havebeen reported.In this paper, a new5,10,15,20-tetra{4-[(N-carbazyl)butyloxyphenyl]}porphyrin(P) and10different metalloporphyrins were prepared with5,10,15,20-tetra(4-hydroxyphenyl)porphyrin and characterized by means of1H NMR, MS, UV-Vis,IR, Raman spectra and element analysis. Their surface photovoltage and fluorescenceproperties were studied. The platinum porphyrin and palladium porphyrin areassembled with mesoporous silica SBA-15and MCM-41and theirluminescence-based optical oxygen-sensing properties were studied. Our workincludes the following aspects:1. We synthesized the5,10,15,20-tetra (4-hydroxyphenyl)porphyrin with4-hydroxybenzaldehyde and pyrrole in acidic conditions according to Adler-Longomethod. And then,5,10,15,20-tetra{4-[(N-carbazyl)butyloxyphenyl]}porphyrin wassynthesized with5,10,15,20-tetra (4-hydroxyphenyl)porphyrin and N-(8-bromobutyl)carbazole. We purified the porphyrin by silica gel columnchromatography. We got10different metalloporphyrins, including6transitionmetalloporphyrins and4lanthanon metalloporphyrins in different solvents anddifferent reaction temperatures. Every compound has been characterized by means of1H NMR, UV-Vis, IR, Raman spectra and element analysis. The reaction process canbe represented by the following equation:2. We studied the fluorescence properties and surface photovoltage properties ofthe new carbazyl substitute porphyrin and its metalloporphyrins. Firstly, we studiedthe fluorescence properties of the carbazyl substitute porphyrin and metalloporphyrins,calculated the quantum yield of them at room temperature. For transition metalcomplexes, the fluorescence intensity of Zn porphyrin was relatively large. And Ni, Ptand Pd porphyrin are much weaker. The paramagnetic Co and Cu porphyrin evenproduce fluorescence quenching. The fluorescence intensity of Pt porphyrin wassignificantly influenced by oxygen concentrations in dichloromethane solution and in solid-state. The fluorescence intensity and the quantum yield of lanthanonmetalloporphyrins were minor. We tested the surface photovoltage spectroscope (SPS)and the electric-field-induced SPS of the porphyrin P and the8metalloporphyrins.Except the porphyrin P, most porphyrin compounds showed good photovoltageresponse. Contrary to the results of the fluorescence intensity of porphyrin complexes,there were high surface photovoltage of porphyrin complexes without external field.Competition process was showed between fluorescence intensity and surfacephotovoltage intensity. Surface photovoltage spectra of porphyrin complexes wereinfluence by the property of external electric field.3. The platinum porphyrin and palladium porphyrin were assembled withmesoporous silica MCM-41resulting in the assembly materials PPt/MCM-41andPPd/MCM-41, the platinum porphyrin and palladium porphyrin were oxygen sensingmolecule and mesoporous silica MCM-41was carrier. The luminescence-basedoptical oxygen characters of PPt/MCM-41have high sensitivity, fast response time,fast recovery time and non-linear Stern–Volmer plots. The response time, recoverytime and sensitivity of oxygen sensing materials based on PPt/MCM-41(20mg/g)were2.0s,14.5s and3853.0, indicating that platinum porphyrin complex/MCM-41systems can be employed to develop high performance oxygen sensors. Assemblymaterials PPd/MCM-41did not possess oxygen-sensing properties.4. The platinum porphyrin and palladium porphyrin were assembled withmesoporous silica SBA-15resulting in the assembly materials PPt/SBA-15andPPd/SBA-15, the platinum porphyrin and palladium porphyrin were oxygen sensingmolecule and mesoporous silica SBA-15was carrier. Due to the porous structure ofSBA-15has much larger pore volume, the luminescence-based optical oxygencharacters of PPt/SBA-15have highest sensitivity, fast response time, fast recoverytime and non-linear Stern–Volmer plots. The response time, recovery time andsensitivity of oxygen sensing materials based on PPt/SBA-15(20mg/g) were3.0s,17.0s and8779.8, To our knowledge, it is the highest value for optical oxygensensors based on platinum porphyrins that has been achieved until now. Platinumporphyrin complex/SBA-15systems can be employed to develop high performance oxygen sensors. Assembly materials PPd/SBA-15did not possess oxygen-sensingproperties.