Sunesh Chozhidakath Damodharan, Shanmugasundaram Kanagaraj, Subeesh Madayanad Suresh, Chitumalla Ramesh Kumar, Jang Joonkyung, Choe Youngson
†Department of Polymer Science and Chemical Engineering, Pusan National University, Busan 609-735, South Korea.
‡Department of Nanomaterials Engineering, Pusan National University, Busan, 609-735, Republic of Korea.
ACS Appl Mater Interfaces. 2015 Apr 15;7(14):7741-51. doi: 10.1021/acsami.5b00875. Epub 2015 Apr 2.
Two new cationic iridium complexes, [Ir(ppy)2(phpzpy)]PF6 (complex 1) and [Ir(dfppy)2(phpzpy)]PF6 (complex 2), bearing a 2-(3-phenyl-1H-pyrazol-1-yl)pyridine (phpzpy) ancillary ligand and either 2-phenylpyridine (Hppy) or 2-(2,4-difluorophenyl)pyridine (Hdfppy) cyclometalating ligands, were synthesized and fully characterized. The photophysical and electrochemical properties of these complexes were investigated by means of UV-visible spectroscopy, emission spectroscopy, and cyclic voltammetry. Density functional theory (DFT) and time dependent DFT (TD-DFT) calculations were performed to simulate and study the photophysical and electrochemical properties of both complexes. Light-emitting electrochemical cells (LECs) were fabricated by incorporating complexes 1 and 2, which respectively exhibit blue-green (488 and 516 nm) and blue (463 and 491 nm) emission colors, achieved through the meticulous design of the ancillary ligand. The luminance and current efficiency measurements recorded for the LEC based on complex 1 were 1246 cd m(-2) and 0.46 cd A(-1), respectively, and were higher than those measured for complex 2 because of the superior balanced carrier injection and recombination properties of the former.
合成并全面表征了两种新型阳离子铱配合物，即[Ir(ppy)₂(phpzpy)]PF₆（配合物1）和[Ir(dfppy)₂(phpzpy)]PF₆（配合物2），它们带有2-(3-苯基-1H-吡唑-1-基)吡啶（phpzpy）辅助配体以及2-苯基吡啶（Hppy）或2-(2,4-二氟苯基)吡啶（Hdfppy）环金属化配体。通过紫外可见光谱、发射光谱和循环伏安法研究了这些配合物的光物理和电化学性质。进行了密度泛函理论（DFT）和含时密度泛函理论（TD-DFT）计算，以模拟和研究这两种配合物的光物理和电化学性质。通过精心设计辅助配体，分别制备了包含配合物1和配合物2的发光电化学电池（LEC），配合物1和配合物2分别呈现蓝绿色（488和516 nm）和蓝色（463和491 nm）发射颜色。基于配合物1的LEC记录的亮度和电流效率测量值分别为1246 cd m⁻²和0.46 cd A⁻¹，由于前者具有更优异平衡的载流子注入和复合性质，所以高于配合物2的测量值。
