Boron Dipyrromethene (Bodipy) Phosphorescence Revealed in [Ir(ppy)2(bpy-C≡C-Bodipy)]+

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• 作者：Aaron A. Rachford ; Raymond Ziessel ; Thomas Bura ; Pascal Retailleau ; Felix N. Castellano
• 刊名：Inorganic Chemistry
• 出版年：2010
• 出版时间：April 19, 2010
• 年：2010
• 卷：49
• 期：8
• 页码：3730-3736
• 全文大小：858K
• 年卷期：v.49,no.8(April 19, 2010)
• ISSN：1520-510X

文摘

The synthesis, structural characterization, electrochemistry, and molecular photophysics of [Ir(ppy)₂(bpy-C≡C-Bodipy)](PF₆), where ppy is 2-phenylpyridine and bpy-C≡C-Bodipy is 5-ethynyl-2,2′-bipyridine-8-phenyl-1,3,5,7-tetramethyl-4,4-bis(2,5-dioxaoct-7-ynyl)-4-bora-3a,4a-diaza-s-indacene (4), is presented. Static and dynamic photoluminescence and absorption measurements in conjunction with cyclic voltammetry were employed to elucidate the nature of the intramolecular energy transfer processes occurring in the excited state of the title chromophore. Parallel studies were performed on appropriate model chromophores (2 and 3) intended to represent the photophysics of the isolated molecular subunits, that is, triplet metal-to-ligand-charge-transfer (³MLCT) and triplet Bodipy intraligand (³IL) excited states, respectively. Upon charge transfer excitation of the title chromophore, the ³MLCT based phosphorescence readily observed in 2 (Φ_em = 0.027, τ = 243 ns) is quantitatively quenched resulting from production of the ³Bodipy excited state through intramolecular triplet−triplet energy transfer. The formation of the ³Bodipy-localized excited state is confirmed by features in the transient absorption difference spectrum, extended excited-state lifetime (τ = 25 μs), as well the observation of ³IL Bodipy-based phosphorescence detected at 730 nm at 77 K. The low temperature Bodipy phosphorescence is readily produced in 4 as a result of the internal Ir(III) heavy atom.