Synthesis and near-infrared luminescence of a deuterated conjugated porphyrin dimer for probing the mechanism of non-radiative deactivation
Synthesis and near-infrared luminescence of a deuterated conjugated porphyrin dimer for probing the mechanism of non-radiative deactivation
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DOI：
10.1039/b700408g
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发表时间：
2007-01-01
影响因子：
3.2
通讯作者：
Anderson, Harry L.
中科院分区：
文献类型：
--
作者：
Frampton, Michael J.;Accorsi, Gianluca;Anderson, Harry L.
β，meso，β-稠合卟啉低聚物具有许多有吸引力的物理化学特征，例如在波长大于1000 nm的近红外中的强吸收和高双光子截面。然而，它们的超快S-1-S-0失活（k（d）> 10（11）s（-1））限制了潜在的应用。我们合成了一种氘代稠合卟啉二聚体，以测试氘代是否影响非辐射失活的速率。发展了一种有效的合成策略，从二吡咯甲烷的氘代反应开始。锌卟啉二聚体的氘化不影响其在CD 2Cl 2中的荧光量子产率（Phi（fD）/Phi（fH）= 1.00 +/-0.05）。这意味着超快非辐射失活不仅仅是小的S-1-S-0能隙的结果。与其他共轭卟啉低聚物的比较证实，在边缘稠合的低聚物的失活速率比从能隙定律预期的要快。该结果表明，应该可以产生具有与β、内消旋、β-稠合卟啉低聚物相似的S-1-S-0能隙但具有较慢的S-1-S-0衰减速率的近IR染料。
beta,meso,beta-Fused porphyrin oligomers have many attractive photophysical features such as strong absorption in the near-IR at wavelengths greater than 1000 nm, and high two-photon cross sections. However their ultrafast S-1-S-0 deactivation (k(d) > 10(11) s(-1)) limits potential applications. We have synthesised a deuterated fused porphyrin dimer to test whether deuteration influences the rate of non-radiative deactivation. An efficient synthetic strategy was developed, starting with deuteration of dipyrromethane. Deuteration of the zinc porphyrin dimer does not affect its fluorescence quantum yield in CD2Cl2 (Phi(fD)/Phi(fH) = 1.00 +/- 0.05). This implies that the ultrafast non-radiative deactivation is not simply a consequence of the small S-1-S-0 energy gap. Comparison with other conjugated porphyrin oligomers confirms that the deactivation rate in the edge-fused oligomers is faster than would be expected from the energy gap law. This result indicates that it should be possible to create near-IR dyes with similar S-1-S-0 energy gaps to the beta,meso,beta-fused porphyrin oligomers but with slower rates of S-1-S-0 decay.