室温有机磷光分子材料的理论研究
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- 英文论文题名：Theoretical Study on Room-Temperature Phosphorescent Organic Molecules
- 论文作者：张国桢 ; 刘然 ; 王涛 ; 杨丽 ; 江俊
- 英文论文作者：Guozhen Zhang ; Ran Liu ; Tao Wang ; Li Yang ; Jun Jiang ; Department of Chemical Physics ; University of Science and Technology of China
- 年：2016
- 作者机构：中国科学技术大学化学物理系;
- 论文关键词：磷光 ; 有机分子 ; 激发态 ; 密度泛函计算
- 会议召开时间：2016-07-01
- 会议录名称：中国化学会第30届学术年会摘要集-第四十分会：纳米体系理论与模拟
- 语种：中文
- 分类号：TQ422
- 学会代码：ZGHY
- 会议名称：中国化学会第30届学术年会-第四十分会 ; 纳米体系理论与模拟
- 会议地点：中国辽宁大连
- 主办单位：中国化学会
- 学会名称：中国化学会
- 页数：1
- 文件大小：208k
- 原文格式：D
- 会议级别：全国
摘要
在磷光材料研究中,室温有机磷光分子材料是一个前景广阔的方向。与金属有机磷光分子相比,有机分子毒性更小,在水溶液中稳定性更高。磷光活性的先决条件是实现分子的单重态激发态到三重态激发态的系间窜越~([1])。缩小第一单重态激发态(S_1)与某个三重态激发态(T_n)的能量差(ΔE_(ST)),是提升S-T系间窜越速率的有效手段。通过第一性原理计算,我们发现可以利用官能团修饰有机分子,创造S-T系间窜越的有利条件,从而发展出新的磷光有机分子材料~([2])。电子结构计算结果表明,特定的官能团可以调节有机分子的最高和次高占据轨道的次序,进而改变S1和T2态的性质,并显著缩小S_1态与T_2态的ΔE_(ST),达到促进系间窜越,提高磷光活性的效果。这一结果为研制新的磷光分子材料提供了新的思路。
Room-temperature phosphorescent organic molecules are promising candidates of phosphorescent molecular materials thanks to their low toxicity and high stability relative to phosphorescent organometallic materials. Efficient intersystem crossing(ISC) from singlet excited states to triplet excited states are prerequisite of phosphorescent activity. A recent experimental work suggested that prompting ISC by using certain functional groups can be a useful way to make new phosphorescent organic materials with sub-second lifetime. We then studied the proposed mechanism by first principle calculations. The computations showed that certain functional groups not only turn both lowest singlet excited state and second lowest triplet excited state into charge transfer states, but also appreciably reduce the energy gap between them, which creates an advantageous condition for S-T ISC. This new mechanism provides an alternative way to make new phosphorescent organic materials.
Room-temperature phosphorescent organic molecules are promising candidates of phosphorescent molecular materials thanks to their low toxicity and high stability relative to phosphorescent organometallic materials. Efficient intersystem crossing(ISC) from singlet excited states to triplet excited states are prerequisite of phosphorescent activity. A recent experimental work suggested that prompting ISC by using certain functional groups can be a useful way to make new phosphorescent organic materials with sub-second lifetime. We then studied the proposed mechanism by first principle calculations. The computations showed that certain functional groups not only turn both lowest singlet excited state and second lowest triplet excited state into charge transfer states, but also appreciably reduce the energy gap between them, which creates an advantageous condition for S-T ISC. This new mechanism provides an alternative way to make new phosphorescent organic materials.
引文
[1]Turro,N.J.;Ramamurthy,V.;Scaiano,J.C.Principles of Molecular Photochemistry.Sausalito,CA:University Science Books;2009.
[2]Chen,X.;Xie,T.;Xu,C.;Zhou,C.;Wang,T.;Du,J.;Xu,H.;Zhang,X.;Zhang,G.Angew.Chem.Int.Ed.in revision.
[2]Chen,X.;Xie,T.;Xu,C.;Zhou,C.;Wang,T.;Du,J.;Xu,H.;Zhang,X.;Zhang,G.Angew.Chem.Int.Ed.in revision.