Increasing phosphorescent quantum yields and lifetimes of platinum-alkynyl complexes with extended conjugation
Increasing phosphorescent quantum yields and lifetimes of platinum-alkynyl complexes with extended conjugation
复制标题
通过延长共轭提高铂-炔基配合物的磷光量子产率和寿命
DOI：
10.1039/c7dt01817g
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发表时间：
2017
影响因子：
4
通讯作者：
Cook Timothy R.
中科院分区：
文献类型：
--
作者：
Zhang Yuzhen;Hauke Cory E.;Crawley Matthew R.;Schurr Bradley E.;Fulong Cressa Ria P.;Cook Timothy R.
铂-炔基络合物与末端吡啶基部分的发射在简单的烷基化反应后发生变化。由于人们对光化学、生物化学和发光器件的兴趣越来越大，理解这些变化的性质对于开发简单的合成途径以合理设计生物活性分子是很重要的。在此，选择的配体异构体，甲基化，和铂配位环境上的磷光量子产率，寿命，和相关的辐射和非辐射速率常数的8个有机金属配合物进行了研究。单晶X射线衍射实验和计算研究提供了证据的稳定的金属-cumulene共振形式，其增加的刚性表现在所观察到的物理变化。这种效应对于4-乙炔基吡啶络合物比3-乙炔基吡啶变体更明显，因为金属-累积多烯形式将电子密度转移到帕拉的电负性N原子。此外，通过引入σ-供电子的N-杂环卡宾来完善Pt的配位环境，使磷光量子产率提高到39%（λmax = 512 nm），寿命为21.2 μs。
The emission of platinum-alkynyl complexes with terminal pyridyl moieties changes upon simple alkylation reactions. Due to growing interest in photovoltaics, photocatalysis, and light-emitting devices, understanding the nature of these changes is important to develop simple synthetic pathways for the rational design of photophysically active molecules. Herein, the choice of ligand isomer, methylation, and Pt-coordination environment on phosphorescent quantum yields, lifetimes, and associated radiative and non-radiative rate constants of eight organometallic complexes were studied. Single-crystal X-ray diffraction experiments and computational studies provide evidence for stabilization of metallo-cumulene resonance forms whose increased rigidities manifest in the observed photophysical changes. This effect is more pronounced for 4-ethynylpyridyl complexes over 3-ethynylpyridyl variants since the metallo-cumulene form shifts electron density to the electronegative N-atom at the para site. Furthermore, the use of σ-donating N-heterocyclic carbenes to complete the Pt-coordination environment enhanced the quantum yield of phosphorescence as high as 39% (λmax = 512 nm) with a lifetime of 21.2 μs.