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论文类型：期刊论文

发表时间：2012-08-07

发表刊物：DALTON TRANSACTIONS

收录刊物：SCIE、EI、PubMed、Scopus

卷号：41

期号：29

页面范围：8931-8940

ISSN号：1477-9226

摘要：The preparation of rhenium(I) tricarbonyl polypyridine complexes that show a strong absorption of visible light and long-lived triplet excited state and the application of these complexes as triplet photosensitizers for triplet-triplet annihilation (TTA) based upconversion are reported. Imidazole-fused phenanthroline was used as the N boolean AND N coordination ligand, on which different aryl groups were attached (Phenyl, Re-0; Coumarin, Re-1 and naphthyl, Re-2). Re-1 shows strong absorption of visible light (epsilon = 60800 M-1 cm(-1) at 473 nm). Both Re-1 and Re-2 show long-lived T-1 states (lifetime, tau(T), is up to 86.0 mu s and 64.0 mu s, respectively). These properties are in contrast to the weak absorption of visible light and short-lived triplet excited states of the normal rhenium(I) tricarbonyl polypyridine complexes, such as Re-0 (epsilon = 5100 M-1 cm(-1) at 439 nm, tau(T) = 2.2 mu s). The photophysical properties of the complexes were fully studied with steady state and time-resolved absorption and emission spectroscopes, as well as DFT calculations. The intra-ligand triplet excited state is proposed to be responsible for the exceptionally long-lived T-1 states of Re-1 and Re-2. The Re(I) complexes were used as triplet photosensitizers for TTA based upconversion and an upconversion quantum yield up to 17.0% was observed.