DFT and TD ‐DFT study of iridium complexes with low‐color‐temperature and low‐efficiency roll‐off properties

A series of heteroleptic cyclometalated Ir (III) complexes, which are used for OLED application, were investigated by DFT and TD ‐DFT method. The frontier molecular orbital character and charge transfer character show that they have the advantages of low‐efficiency roll‐off and low‐color‐temperature properties, which is a ‘stumbling block’ in the process of OLED solid‐lighting's development. This means that th e materials play an important role in the development of OLED. A series of heteroleptic cyclometalated Ir (III) complexes with low ‐color‐temperature and low‐efficiency roll‐off properties, which cause a fast reduction in efficiency when the drive current increases, for organic light‐emitting devices are investigated theoretically to explore their electronic structures and spectroscopic properties. The geometries, ele ctronic structures, lowest‐lying singlet absorptions and triplet emissions of (ptpy)2Ir(acac), and the theoretically designed models (ptpy)2Ir(tpip), (F ‐ptpy)2Ir(acac), (F ‐ptpy)2Ir(tpip), (F2‐ptpy)2Ir(acac) and (F2‐ptpy)2Ir(tpip), are investigated with density functional theory approaches, where ptpy denotes 4 ‐phenylthieno [3,2‐c] pyridine, acac denotes acetylacetonate, tpip denotes tetraphenylimido‐diphosphinate, F‐ptpy denotes 4‐(3‐fluorophenyl) thieno [3,2‐c] pyridine, and F2‐ptpy denotes 4‐(2,4‐difluorophenyl) thieno [3,2‐c] pyridine.

Source: Applied Organometallic Chemistry - October 31, 2018 Category: Chemistry Authors: Zheng ‐Kun Qin, Ke‐Chuan He, Peng Lü, Ming‐Xing Song, Yong‐Ling Zhang, Chun‐Xu Wang, Shu‐Yan Song, Shi‐Quan Lü, Fu‐Quan Bai, Hong‐Jie Zhang Tags: FULL PAPER Source Type: research