Translated Titles

The Photophysical Properties of Iridium(III) and Osmium(II) Complexes Containing Isoquinoline Family Ligands





Key Words

銥 ; 鋨 ; 異喹啉光物理 ; 磷光 ; Iridium ; Osmium ; photophysical properties ; phosphorescence



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Chinese Abstract

本篇論文研究內容主要探討含異喹啉族配位基的有機銥、鋨金屬錯合物之光物理性質。第一章先簡介分子吸收放光機制,以及光譜測量實驗上所使用儀器的基本原理及操作,在接下來的章節,分別就三個主題來討論。 首先,描述一系列含P^O輔助基的銥金屬錯合物發光材料之設計概念,這些銥金屬錯合物藉由pyridine (ppy), isoquinoline (piq)和quinazoline (nazo)不同的發光基團調控,磷光放光可以由綠色改變至紅色,不論在除氧的溶液態以及固態都有相當不錯的量子效率,並且具有效率高、壽命長的優點。在第二章中,我們主要探討這系列銥金屬錯合物的光物理性質。 第三章的部分提到一系列含有isoquinoline-triazolate和isoquinoline-pyrazolate的鋨金屬錯合物。這系列的錯合物同時具有螢光以及磷光放光。有趣的是,其螢光和磷光的比例與激發波長有關,激發波長愈短,磷光的比例也隨之增加,可能的原因是當分子被激發到較高的激發態時,具有較高MLCT比例的激發態導致系統間內轉換的速率較快,因此短波長激發可以得到較高比例的磷光。這樣的觀察和一般認知的光物理現象有些不同,我們藉由進一步的實驗證明所提出的假設。 最後一章,我們主要探討endoperoxide受熱分解所導致的化學放光,藉由測量單氧在紅外光(1275 nm)的放光,得到endoperoxide受熱分解產生單氧的直接證據。隨著溫度升高,反應速率常數增大;單位時間內單氧產生的數量增加,放光也會增強。在此,我們比較1,4-dimethylnaphthalene endoperoxide和9,10-diarylanthracence endoperoxide這兩個化合物受熱分解所放出的單氧放光強度,討論反應活化能以及溫度等其他可能影響反應發生的因素,進而思考其改進條件和未來之應用方向。

English Abstract

The purpose of this study is to discuss the photophysical properties of Iridium(III) and Osmium(II) complexes containing isoquinoline family ligands. The first chapter introduces the basic principles of light absorption and the emission of the molecule. The instrumental setups and principles of operation are also presented. With these fundamental conceptions in mind, we will discuss three topics in the following chapters. First of all, we report the design concept of a series of emissive Ir(III) complexes employing ancillary P^O chelate, for which its PPh2 fragment is well known for the excellent π-accepting characteristics and classified as one of the strong field ligand in the second chapter. These Ir(III) complexes, bearing the chromophore ligand pyridine (ppy), isoquinoline (piq) and quinazoline (nazo) respectively, exhibit green-to-red photoluminescence with moderate to high quantum efficiencies in the degassed fluid state and bright emission in solid state. The photophysical properties and application of these Ir(III) phosphorescent emitters for highly efficient, long-life organic light-emitting diodes are discussed in detail. In the third chapter, we would concentrate on the photophysical properties of a series of Os(II) complexes bearing isoquinoline-triazolate and isoquinoline-pyrazolate moieties respectively. These Os(II) complexes show salient dual emissions consisting of fluorescence and phosphorescence. The yield of phosphorescence is significantly increased as tuning the excitation wavelength from long to short wavelength in common solvents; that is excitation wavelength dependent. The results are rationalized by the increase of metal-ligand-charge-transfer (MLCT) contribution in the highly excited states, drastically enhancing the spin-orbit coupling and hence the intersystem crossing. This observation, being against Kasha’s rule, is also opposites of the well established photophysical phenomena. Finally, the last chapter presents the chemiluminescence for the decomposition of 1,4-dimethylnaphthalene endoperoxide and 9,10-diarylanthracence endoperoxide. We observed singlet oxygen 1∆g->3Σg− infrared emission at maxima 1275 nm for the thermal decomposition of endoperoxide in solutions. The results demonstrate that O2 is eliminated in the 1∆g state upon endoperoxide decomposition on the ground state surface. The thermoluminescence spectra of 9,10-diarylanthracene endoperoxide were observed at higher temperature in comparison with 1,4-dimethylnaphthalene endoperoxide. In addition, the rate constants for the disappearance of endoperoxides were found to be dependent on temperature. The activation parameters (∆E‡, A) as well as the rate constants and half life at various temperatures were also mentioned.

Topic Category 基礎與應用科學 > 化學
理學院 > 化學研究所
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