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Phosphorescent Iridium( III ) Cyclometalates Supported by 2‐(1,2‐Dihydronaphthalen‐4‐yl)pyridine Ligand
Author(s) -
Park Jae Young,
Lee Min Hyung
Publication year - 2017
Publication title -
bulletin of the korean chemical society
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.237
H-Index - 59
ISSN - 1229-5949
DOI - 10.1002/bkcs.11148
Subject(s) - iridium , chemistry , phosphorescence , ligand (biochemistry) , ring (chemistry) , homo/lumo , photoluminescence , pyridine , crystallography , cyclic voltammetry , photochemistry , electrochemistry , medicinal chemistry , molecule , fluorescence , materials science , catalysis , organic chemistry , physics , biochemistry , receptor , optoelectronics , electrode , quantum mechanics
Novel Ir( III ) cyclometalates, (dnpy) 2 Ir (acac) ( 2 ) and fac ‐Ir(dnpy) 3 ( 3 ), supported by 2‐(1,2‐dihydronaphthalen‐4‐yl)pyridyl ligand (dnpy) were synthesized and characterized. X‐ray diffraction study on 3 revealed facial arrangement of three dnpy ligands around the Ir center. Photoluminescence ( PL ) spectra of 2 exhibited orange emission centered at 590 nm, which is almost similar to that observed for 2‐naphthylpyridine complex, (napy) 2 Ir (acac) ( III ). In contrast, compound 3 displayed blue‐shifted, yellow emission at 550 nm. Tris‐complex 3 showed higher quantum efficiencies than 2 in both the solution and film states. Cyclic voltammetry measurements indicated that replacing naphthyl with 1,2‐dihydronaphthyl ring raises both the metal‐centered HOMO level and ligand‐centered LUMO level in 2 and 3 . It was suggested that 1,2‐dihydronaphthyl ring has a stronger electron‐donating effect than naphthyl ring, while the π* orbital of dnpy ligand is less stabilized due to partial conjugation of the dihydronaphthyl ring.