| Abstract
| - To examine the effect of substituent groups on the luminescence of BPh2(X-2-PI) complexes,three new air-stable boron complexes BPh2(F-2-PI) (5a), BPh2(Cl-2-PI) (5b), and BPh2(CH3O-2-PI) (5c) were synthesized and characterized, where F-2-PI = 5-fluoro-2-(2‘-pyridyl)indole,Cl-2-PI = 5-chloro-2-(2‘-pyridyl)indole, and CH3O-2-PI = 5-methoxyl-2-(2‘-pyridyl)indole. Inthese complexes, the 5-substituted 2-PI ligand chelates in a tretrahedral fashion to the boroncenter. Compounds 5a−c are luminescent, with 5a having the highest emission efficiency.Compared with the emission maximum of BPh2(2-PI) (516 nm), the emission maximum of5a and 5b is blue-shifted to 490 and 487 nm, respectively, while the emission of 5c is red-shifted to 532 nm, indicating the possibility of tuning the luminescence of these complexesby varying the substituent groups on the 2-PI ligand. An electroluminescent device usingcompound 5a as the emitter and the electron transport material has been fabricated.
- Substituent groups on the 5-position of 2-(2‘-pyridyl)indole ligand have a significant effect on the luminescence of the diphenylboron complexes BPh2(X-2-PI); the 5-fluoro-substituted complex BPh2(F-2-PI) is the most promising as an emitter for EL applications.
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