Bis-cyclometalated Ir(III) complexes as efficient singlet oxygen sensitizers
| Autor: | Matthias Selke, David Ho, Mark E. Thompson, Billy Hernandez, Peter I. Djurovich, Ruomei Gao, Drew Murphy |
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| Rok vydání: | 2002 |
| Předmět: |
Quenching (fluorescence)
Photosensitizing Agents Singlet Oxygen Chemistry Singlet oxygen Ligand Acetylacetone Quantum yield General Chemistry Photochemistry Iridium Biochemistry Medicinal chemistry Catalysis chemistry.chemical_compound Colloid and Surface Chemistry Benzothiazole Excited state Pyridine Organometallic Compounds |
| Zdroj: | Journal of the American Chemical Society. 124(50) |
| ISSN: | 0002-7863 |
| Popis: | We report the singlet oxygen sensitization properties of a series of bis-cyclometalated Ir(III) complexes (i.e., (bt)2Ir(acac), (bsn)2Ir(acac), and (pq)2Ir(acac); bt = 2-phenylbenzothiazole, bsn = 2-(1-naphthyl)benzothiazole, pq = 2-phenylquinoline, and acac = acetylacetonate). Complexes with acetylacetonate ancillary ligands give singlet oxygen quantum yields near unity (PhiDelta = (0.7-1.0) +/- 0.1), whether exciting the ligand-based state or the lowest energy excited state (MLCT + 3LC). The singlet oxygen quenching rates for these beta-diketonate complexes were found to be small [(5 +/- 2) x 105 to (6 +/- 0.2) x 106 M-1 s-1], roughly 3 orders of magnitude slower than the corresponding phosphorescence quenching rate. Similar complexes were prepared with glycine or pyridine tethered to the Ir(III) center (i.e., (bsn)2Ir(gly) and (bt)2Ir(py)Cl; gly = glycine and py = pyridine). The glycine and pyridine derivatives give high singlet oxygen yields (PhiDelta = (0.7-1.0) +/- 0.1). |
| Databáze: | OpenAIRE |
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