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The Study On Synthesis And Luminescence Performance Of Meso-Arylpyrazolylporphyrin

Posted on:2006-11-12Degree:DoctorType:Dissertation
Country:ChinaCandidate:T G RenFull Text:PDF
GTID:1101360182970279Subject:Applied Chemistry
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Although certain blue-and green-emitting materials have efficiencies sufficient for practical use, red-emtting materials with low brightness, impure color (unsaturated emission) and low efficiency are still not satisfactory. It is vitally nessary to research the red organic electroluminescent for developing full-color display of OLEDs. Porphyrin compounds are ideal red-emitting materials due to their excellent opoelectronic properties. Presently, although the saturated red color chromaticity of porphyrin-type red dopants is satisfactory for practical use, there exist two main problems in red organic electroluminescent devices (OLED) doped by porphyrin compounds, namely, low photoluminescent yields of fluorescent dyes and poor energy transfer from the host to the guest. In this report, a series of nitrogen heterocycle porphyrin compounds were obtained by introducing a pyrazole heterocyclic ring with high fluorescent quantum yield to the parent porphyrin. These porphyrin compounds exhibit the outstanding red-shifted of UV-Vis and fluorescence spectra, and increased fluorescence quantum yields compare with TPPH2. Then, the host materials are changed from tris (8-hydroxylquinoline) aluminum to TPD in order to achieve more efficient energy transfer. These works help to accelerate the research and development of red organic electroluminescent materials. The main contents are as follows: 1. meso-tetrakis(1-arylpyrazol-4-yl)porphyrin' synthesis Six meso-tetrakis(1-arylpyrazol-4-yl)porphyrins have been designed and synthesized. Preparation of these porphyrins was carried out by cyclization of tetramethoxypropane with substituted phenylhydrazine, followed by formylation under Vilsmeier-Haack condition to give the corresponding aldehydes, which reacted with pyrrole under the Adler reaction condition to get the target porphyrins. The structures of all these compounds were characterized by 1HNMR, elemental analysis, UV-Vis spectra and mass spectra. The formylation reaction of pyrazole heterocyclic and the synthetic methods of porphyrins have been studied too. 2. Analysis of the Uv-Vis spectra and fluorescence spectra of meso-tetrakis (1-arylpyrazol-4-yl)porphyrin Red fluorescence emission of these porphyrins was observed in fluorescence spectra. Compared with meso-tetraphenylporphyrin (TPPH2), these meso-tetrakis(1-arylpyrazol-4-yl) porphyrins had outstanding red shift in UV-Vis and fluorescence spectra with increased fluorescence quantum yields. A reasonable explain for their spectral properties was given. 3. Fabrication of the organic electroluminescent devices with meso-tetrakis (1-arylpyrazol-4-yl)porphyrins as dopant and study of the EL performance of meso-tetrakis(1-arylpyrazol-4-yl) porphyrins To study the EL performance of meso-tetrakis(1-arylpyrazol-4-yl)porphyrins, the organic electroluminescent devices are prepared with meso-tetrakis(1-arylpyrazol-4-yl) porphyrins as dopant and tris(8-hydroxyl quinoline)aluminum as host. We study the effects of different doping concentration of the same porphyrin and different porphyrin compounds of the same doping concentration on electroluminescent performances including electroluminescent spectra, color, luminance and efficiency. Then, the reasonable analyses are given by studying mechanism. 4. The influence of energy transfer from the host to the guest on EL performances of devices We prepare organic electroluminescent devices with meso-tetrakis(1-aryl pyrazol-4-yl) porphyrins as dopant and TPD as host and analyze on the performances of devices. Then, we prepare organic electroluminescent devices with meso-tetrakis(1-arylpyrazol-4-yl)porphyrins and tris(8-hydroxylquinoline) aluminum as dopants and TPD as host and study the influence of different doping concentration of tris(8-hydroxylquinoline)aluminum on electroluminescent performances including electroluminescent spectra, color, luminance and efficiency. Then, the reasonable analyses are given by studying mechanism.
Keywords/Search Tags:meso-tetrakis(1-arylpyrazol-4-yl)porphyrins, design, synthesis, characterize, OLEDs, Red luminescence, spectra, EL performance
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