New luminescent cyclometalated iridium(III) complexes containing fluorinated phenylisoquinoline-based ligands: Synthesis, structures, photophysical properties and DFT calculations

• Published in: Chinese chemical letters 2016-03, Vol.27 (3), p.428-432
• Main Authors: Li, Gao-Nan, Gao, Cheng-Wei, Xie, Hui, Chen, Hao-Hua, Liu, Dong, Sun, Wei, Chen, Guang-Ying, Niu, Zhi-Gang
• Format: Article
• Language: English
• Subjects: Crystal structure; DFT calculation; Iridium(III) complex; Phenylisoquinoline; Photoluminescence
• ISSN: 1001-8417; 1878-5964
• DOI: 10.1016/j.cclet.2015.12.007

Two new fluorinated phenylisoquinoline-based iridium(III) complexes have been synthesized and fully characterized. Their photophysical properties have been investigated, and the lowest-energy electronic transitions of absorption spectra have been analyzed by means of time-dependent density functional theory (TD-DFT). Two new fluorinated phenylisoquinoline-based iridium(III) complexes, [Ir(f2piq)2(bipy)][PF6] (3a) and [Ir(fmpiq)2(bipy)][PF6] (3b) (f2piq=1-(2,4-difluorophenyl)isoquinoline, fmpiq=1-(4-fluoro-2-methylphenyl)isoquinoline, bipy=2,2′-bipyridine), have been synthesized and fully characterized. Single crystal X-ray diffraction study has been undertaken on complexes 3a and 3b, which show that each adopts the distorted octahedral coordination geometry with the cis-C,C′ and trans-N,N′ configuration. The photoluminescence spectra of 3a and 3b exhibit yellow and orange emission maxima at 584 and 600nm, respectively. The frontier molecular orbital diagrams and the lowest-energy electronic transitions of 3a–3b have been calculated with density functional theory (DFT) and time-dependent DFT (TD-DFT). The absorption and emission spectra of complex 3b is red-shifted relative to those of complex 3a, as a consequence of the nature of the methyl group.