以理論計算探討重原子過渡金屬其激發態動力學分析和放光性質
No Thumbnail Available
Date
2014
Authors
Journal Title
Journal ISSN
Volume Title
Publisher
Abstract
本論文將探討過渡金屬錯合物之光物理性質,特別針對過渡金屬錯合物Sn 到Tm之間系統間跨越(Intersystem crossing, ISC)的速率之影響參數進行研究。過渡金屬錯合物中心的重原子效應產生之強自旋-軌道交互作用力(spin-orbit coupling, SOC),可以增強系統間跨越的效率,使其有利於放出磷光。若能有效的提升系統間跨越的效率,就可間接加強過渡金屬錯合物放光的量子產率,因此ISC速率的大小是很多光電材料應用上的關鍵因素。本篇將對各種不同類別的發光過渡金屬錯合物進行討論,以理論計算方法預測這些過渡金屬的光物理性質,並與實驗數據相互比較。最終希望能找出影響過渡金屬化合物自旋-軌道耦合(spin-orbit coupling)作用力大小和ISC量子產率之定量關係式的各種因素,如電子結構,如原子序、鍵長、電子躍遷性質、單重態與三重態能階差等。
我們主要以鋨(Osmium) 、釕(Ruthenium)和銅(Copper)、銀(Silver)、金(Gold)等過渡金屬錯合物為討論對象,探討metal-to-ligand charge transfer(MLCT)和中心金屬d軌域對自旋-軌道耦合之影響,以定量的方式計算出自旋-軌道耦合強度大小,並比較內部重原子效應(Internal heavy atom effect)和外部重原子效應(External heavy atom effect)對系統間跨越的差異性。而在最後一部分探討鋨(Osmium)系列過渡金屬錯合物在較高激發態(High-lying excited state)系統間跨越的反應速率遠高於S1→Tm的系統間跨越反應速率之特殊性質。
關鍵字:有機發光二極體,過度金屬錯合物,重原子效應,自旋-軌道耦合作用力,系統間跨越,磷光
In this thesis, we provide a systematic elucidation on the parameters that influence the Sn to Tm intersystem crossing rate (ISC) constant of emissive transition metal complexes, which is a crucial factor in many optoelectronic device applications. Particular attention will be paid to the derivation of rate constant of Sn Tm ISC based on a non-adiabatic approach. Extensive theoretical calculations on a large set of different families of known emissive TM complexes, and a careful comparison between and theoretical predictions and experimental behaviors are performed. The ultimate goal in this thesis is to summarize practical and quantitative rules that govern the magnitude of spin-orbit coupling (SOC) integrals and the overall ISC quantum yield, including the atomic number, bonding distance, types of transition, electronic energy gaps, vibrational relaxations, and etc. Systems mainly studied in this thesis include osmium, ruthenium and copper, silver, gold transition metal complexes. We first explore quantitatively how the metal-to-ligand charge transfer (MLCT) property and the percentage of the central metal d orbital involvement Influence the intersystem crossing rate by quantitatively computing the SOC integrals. In the second part, we compare the internal heavy atom effect and external heavy atom effect for the Group 11 d10 Cu(I), Ag(I), and Au(I) transition metal complexes. Finally, we investigate the spin-orbit coupling strength between the high-lying excited states and lowest-lying excited state for a class of Os(II) complexes. 關鍵字:Organic light-emitting diode,transition metal complexes,heavy atom effect,spin-orbit coupling,Intersystem crossing,phosphorescence
In this thesis, we provide a systematic elucidation on the parameters that influence the Sn to Tm intersystem crossing rate (ISC) constant of emissive transition metal complexes, which is a crucial factor in many optoelectronic device applications. Particular attention will be paid to the derivation of rate constant of Sn Tm ISC based on a non-adiabatic approach. Extensive theoretical calculations on a large set of different families of known emissive TM complexes, and a careful comparison between and theoretical predictions and experimental behaviors are performed. The ultimate goal in this thesis is to summarize practical and quantitative rules that govern the magnitude of spin-orbit coupling (SOC) integrals and the overall ISC quantum yield, including the atomic number, bonding distance, types of transition, electronic energy gaps, vibrational relaxations, and etc. Systems mainly studied in this thesis include osmium, ruthenium and copper, silver, gold transition metal complexes. We first explore quantitatively how the metal-to-ligand charge transfer (MLCT) property and the percentage of the central metal d orbital involvement Influence the intersystem crossing rate by quantitatively computing the SOC integrals. In the second part, we compare the internal heavy atom effect and external heavy atom effect for the Group 11 d10 Cu(I), Ag(I), and Au(I) transition metal complexes. Finally, we investigate the spin-orbit coupling strength between the high-lying excited states and lowest-lying excited state for a class of Os(II) complexes. 關鍵字:Organic light-emitting diode,transition metal complexes,heavy atom effect,spin-orbit coupling,Intersystem crossing,phosphorescence
Description
Keywords
有機發光二極體, 過度金屬錯合物, 重原子效應, 自旋-軌道耦合作用力, 系統間跨越, 磷光, Organic light-emitting diode, transition metal complexes, heavy atom effect, spin-orbit coupling, Intersystem crossing, phosphorescence