Luminescent cyclometalated iridium(III) dipyridoquinoxaline indole complexes as biological probes

Autor: Arthur Ho-Hon Leung, Kenneth Kam-Wing Lo
Rok vydání: 2010
Předmět:
Zdroj: Science China Chemistry. 53:2091-2098
ISSN: 1869-1870
1674-7291
DOI: 10.1007/s11426-010-4120-y
Popis: Four luminescent cyclometalated iridium(III) dipyridoquinoxaline complexes appended with an indole moiety [Ir(N∧C)2(N∧N)] (PF6) (HN∧C = 2-phenylpyridine, Hppy; N∧N = 2-(N-(2-(indole-3-acetamido)ethyl)aminocarbonyl)dipyrido[3,2-f:2′,3′-h]quinoxaline, dpqC2indole (1a), N∧N = 2-(N-(6-(indole-3-acetamido)hexyl)aminocarbonyl)dipyrido[3,2-f:2′,3′-h]quinoxaline, dpqC6indole (1b); HN∧C = 7,8-benzoquinoline, Hbzq, N∧N = dpqC2indole (2a), N∧N = dpqC6indole (2b)) have been synthesized and characterized. Upon irradiation, all the complexes displayed moderately intense and long-lived luminescence under ambient conditions and in 77 K glass. On the basis of the photophysical data, the emission of the complexes has been assigned to an excited state of triplet metal-to-ligand charge-transfer (3MLCT) ((dπ(Ir) → π*(N∧N)) character. Cyclic voltammetric studies revealed indole-based and iridium-based oxidations at ca. +1.10 V and +1.24 V vs. SCE, respectively, and ligand-based reductions at ca. −1.07 to −2.29 V vs. SCE. The interactions of the complexes with an indole-binding protein, bovine serum albumin (BSA), have been examined by emission titrations.
Databáze: OpenAIRE
Externí odkaz: