کد مقاله | کد نشریه | سال انتشار | مقاله انگلیسی | نسخه تمام متن |
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1301384 | 1498929 | 2015 | 5 صفحه PDF | دانلود رایگان |
• Ir(III) complexes containing 5-nitro-2-(2′,4′-difluorophenyl)pyridyl are presented.
• Crystal structures of two new Ir(III) complexes are determined.
• These Ir(III) complexes emit red-orange phosphorescence.
• HOMO–LUMO Eg of these complexes are influenced by the substituents of ligand.
A series of cyclometalated Ir(III) complexes [Ir(dFNppy)2(PPh3)L] (PPh3 = triphenylphosphine, L = Cl−, 1; NCS−, 2; NCO−, 3; N3−, 4) in which 5-nitro-2-(2′,4′-difluorophenyl)pyridyl (dFNppy) is used as the main ligand are synthesized and characterized. The crystal structures of 3 and 4 are determined by X-ray diffraction analyses. Photoluminescence spectra of 1–4 in CH2Cl2 solutions at room temperature show the maximum emission wavelengths (λmax) in the range from 586 to 627 nm, corresponding to red-orange luminescence. HOMO–LUMO energy levels of 1–4 are estimated by cyclic voltammetry measurements. Compared with corresponding 2-phenylpyridyl (ppy)-containing Ir(III) complexes having same ancillary ligands, 1–4 have obviously smaller HOMO–LUMO energy gaps (Eg). Simultaneously, 1–4 show relatively bigger Eg compared with 2-phenyl-5-nitropyridyl (5-NO2-ppy)-containing Ir(III) complexes possessing same ancillary ligands. Methods of Eg adjustment are also discussed.
Graphical AbstractCyclometalated Ir(III) complexes containing 5-nitro-2-(2′,4′-difluorophenyl)pyridyl (dFNppy) are presented. Compared with corresponding ppy-containing Ir(III) complexes with same ancillary ligands, these complexes have obviously smaller Eg. Simultaneously, these complexes show relatively bigger Eg compared with 5-NO2-ppy-containing Ir(III) complexes with same ancillary ligands. The influence of nitro group on Eg is much greater than that of fluorine atoms in these complexes.Figure optionsDownload as PowerPoint slide
Journal: Inorganic Chemistry Communications - Volume 61, November 2015, Pages 152–156