pH Dependence of the energy transfer mechanism in a phenanthridine-appended ytterbium complex
pH Dependence of the energy transfer mechanism in a phenanthridine-appended ytterbium complex
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DOI：
10.1039/b201867p
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发表时间：
2002-01-01
期刊：
影响因子：
--
通讯作者：
Williams, JAG
中科院分区：
文献类型：
--
作者：
Beeby, A;Faulkner, S;Williams, JAG
尽管菲啶的三线态与金属中心的吸收带的重叠可以忽略不计，但从非质子化的菲啶发色团到镱的分子内能量转移迅速发生。这可以通过顺序电子转移和反向电子转移或氧化还原机制来解释。当菲啶被质子化时，这种能量转移途径在热力学上不再可行。在这些情况下，向金属的能量转移成为速率决定因素，并由菲啶鎓三重态介导，尽管其与以金属为中心的吸收带的光谱重叠接近于零。
Intramolecular energy transfer from a non-protonated phenanthridine chromophore to ytterbium occurs rapidly despite negligible overlap of the triplet state of phenanthridine with the absorption band of the metal centre. This can be explained by a sequential electron transfer and back electron transfer, or redox, mechanism. When the phenanthridine is protonated, this energy transfer pathway ceases to be thermodynamically feasible. Under these circumstances, energy transfer to the metal becomes rate determining and is mediated by the phenanthridinium triplet state, despite its near-zero spectral overlap with the metal-centred absorption band.