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Indexed by:期刊论文

Date of Publication:2017-01-01

Journal:DYES AND PIGMENTS

Included Journals:SCIE、EI

Volume:136

Page Number:641-647

ISSN No.:0143-7208

Key Words:Ir(III) complex; Diphenylamino group; Phosphorescence lifetime; Oxygen sensing; Photostability

Abstract:A series of (CN)-N-boolean AND type bis-cyclometalated Ir(III) complexes (Ir1-Ir4) with a diphenylamino group at the 4 position of the phenyl ring of 2-phenylpyridine (ppy) have been prepared and fully characterized. The influences of substituents (-H, -CH3, -F, -CF3) at the pyridyl moiety of ppy on the photophysical and electrochemical properties of these Ir(III) complexes have been investigated systematically by comparison with the model complex Ir(ppy)(2)(acac). The Ir(III) complexes (Ir1-Ir4) show phosphorescence with emission maxima in the range of 530-558 nm, which are all red -shifted relative to Ir(ppy)(2)(acac) (lambda(max) = 518 nm). These Ir(III) complexes demonstrate longer phosphorescence lifetimes and better oxygen-sensitivity than Ir(ppy)(2)(acac). It is remarkable that introduction of both diphenylamino and trifluoromethyl groups into the cyclometalating ligand enhances the photostability of the corresponding Ir(III) complexes efficiently. The results reveal that the bulky and electron-donating characteristics of the diphenylamino group enhance the performances of the Ir(III) complexes in oxygen sensing. (C) 2016 Elsevier Ltd. All rights reserved.