含五苯代苯之配位基的銥錯合物之合成 與其能量轉移、光激發及電激發光性質之研究

Abstract

近年來環型的銥金屬錯合物是具有突破性的磷光發光材料。其元件展現是純有機分子所構成的螢光發光體所無法相比的。紅光及綠光的材料已有令人滿意的發展，但藍光的進展卻困難重重。 本論文的研究主旨在C^Na配位基分子結構的改變以調整磷光材料C^N 2Ir(LX)b發光的顏色。藉由修飾吡啶苯環上的取代基，在苯環上的2、4位置接氟或3、5位置接三氟甲基，探討其發射波長的變化。並引入具有能量轉移的多取代聯苯配位基，同時加強立體障礙，減低濃度所造成的淬熄效應，同時具有能量轉移作用，可提升放光效率。 對這些發光材料作物性及化性上的探討：由TGA測試得知這些磷光材料在200~300℃具有不錯的熱穩定性；由CV測試得知這些磷光材料也具有良好的可逆性；由UV圖可觀察出由於銥（Ⅲ）的強電子自旋偶合效應，可清楚的分析出1MLCT和3MLCT吸收；由PL圖可得到，改變配位基上的取代基可調整材料的發光光色從510nm的綠光位移到485nm的藍光。同時修改有機發光二極體元件，亦具有良好的元件表現。 a：C^N = cyclometalating ligand b：LX = monoanionic and bidentate ancillary ligand

Phosphorescent materials of iridium complexes had been attracted much attention in recent years. The device performance of the pure organic compounds could be scarcely comparable to the inorganic complexes. The red and green materials have progressed in OLED, while the results of blue materials were unsatisfied. The research topic in this article is to tune the color of phosphorescent material of C^N2Ir(LX)b by using various C^Na ligand. Modification of the functional group, by replacing the hydrogen atom to fluoro group at the 2,4 position or CF3 at the 3,5 position on the phenyl ring, we could get emission from green to blue . We also introduce the polyphenyl group for the goal of energy transfer, and increase the steric hindrance to avoid the self quenching between iridium complexes. In the results of the physical and chemical properties of these emitting materials, we observed: (1) They have good thermal stability between 200℃-300℃ by thermogravimetry analysis. (2) They also have good reversibility by the test of cyclic-voltammetry. (3) We could clearly distinguish the 1MLCT from 3MLCT absorption by the result of Ir(III)’s strong spin-orbital coupling effect. (4) In the photoluminescence, we found the emission could be tuned from green (510 nm) to blue (485 nm) by the modification of the substituents. a：C^N = cyclometalating ligand b：LX = monoanionic and bidentate ancillary ligand