Synthesis of heteroleptic iridium complexes with sterically hindered methyl groups on pyrazole ligands for efficient yellow and green light-emitting electrochemical cells
作者:Chozhidakath Damodharan Sunesh、Madayanad Suresh Subeesh、Kanagaraj Shanmugasundaram、Ramesh Kumar Chitumalla、Joonkyung Jang、Youngson Choe
DOI:10.1016/j.dyepig.2016.01.033
日期:2016.5
report the synthesis of four cationic iridium complexes, [Ir(ppy)2(mepzpy)]PF6 (1a), [Ir(dfppy)2(mepzpy)]PF6 (1b), [Ir(ppy)2(dmpzpy)]PF6 (2a), and [Ir(dfppy)2(dmpzpy)]PF6 (2b), containing the methyl-substituted pyrazole-based ancillary ligand and the phenylpyridine-based cyclometalating ligands. UV–visible, photoluminescence (PL), and voltammetric measurements were made to study the photophysical and electrochemical
我们报告了四种阳离子铱络合物[[Ir(ppy)2(mepzpy)] PF 6(1a),[Ir(dfppy)2(mepzpy)] PF 6(1b),[Ir(ppy)2(dmpzpy )的合成)] PF 6(2a)和[Ir(dfppy)2(dmpzpy)] PF 6(2b),含有甲基取代的吡唑基辅助配体和苯基吡啶基环化金属配体。进行了紫外可见光,光致发光(PL)和伏安法测量,以研究配合物1a – 2b的光物理和电化学性质。制备了发光电化学电池(LEC),其对于配合物1a和2a显示黄色发射,而对于配合物1b和2b显示绿色发射。结合了2b的LEC表现出658cd m -2的高亮度和0.34cd A -1的电流效率。基于2b的器件具有更高的亮度和效率,这归因于其光滑的表面形态以及辅助配体(dmpzpy)上存在位阻二甲基基团,从而使电荷载流子注入和重组更加平衡。