Novel phosphorescent iridium(iii) complexes containing 2-thienyl quinazoline ligands: synthesis, photophysical properties and theoretical calculations. Issue 118 (17th November 2015)

• Record Type: Journal Article
• Authors: Mei, Qunbo; Weng, Jiena; Xu, Zhijie; Tong, Bihai; Hua, Qingfang; Shi, Yujie; Song, Juan; Huang, Wei
• Is Part Of: RSC advances. Volume 5:Issue 118(2015)
• Page Start: 97841
• Page End: 97848
• Publication Date: 2015-11-17
• Subjects: Chemistry -- Periodicals; 540.5
• DOI: 10.1039/c5ra17437f
• Languages: English
• ISSNs: 2046-2069

Abstract

Abstract : Highly efficient phosphorescent iridium complexes based on 2-thienyl quinazoline derivatives with various substituents are successfully prepared and fully characterized. Abstract : The easy tailoring of organic ligands of iridium(iii ) complexes provides a facile way to tune their opto-electronic properties for applications in high efficiency phosphorescent light emitting diodes. Herein, a series of yellow and red emitting phosphorescent iridium complexes based on 2-thienyl quinazoline derivatives are successfully synthesized and systematically characterized with various opto-electronic properties. The X-ray crystal structures demonstrate that the iridium centers in the complexes with bulky substituents on the 4-position of quinazolyl rings prefer to chelate with the N atoms in the 1-position of quinazolyl rings. Both experiment and theoretical studies indicate that the steric hindrance along with the electron-donating effect of substituents on the C^N ligands enhances the emission quantum yields, accompanied by significant emission shifts. Two yellow phosphorescent iridium complexes (Ir2 andIr3 ) are successfully designed and exhibit moderate emission efficiencies, through the incorporation of bulky ligands with strong electron-donating abilities (piperidine forIr2 and 2, 6-dimethyl-phenoxy forIr3, respectively). The synergistic effect of electron structure and hindrance of ligand is believed to be a promising strategy for tuning the opto-electronic properties of iridium complexes.