Junker Anne Kathrine R, Hill Leila R, Thompson Amber L, Faulkner Stephen, Sørensen Thomas Just
Nano-Science Center & Department of Chemistry, University of Copenhagen, Universitetsparken 5, 2100 København Ø, Denmark.
Chemistry Research Laboratory, University of Oxford, 12 Mansfield Road, Oxford OX1 3TA, UK.
Dalton Trans. 2018 Apr 3;47(14):4794-4803. doi: 10.1039/C7DT04788F.
Lanthanide based dyes and assays exploit the antenna effect, where a sensitiser-chromophore is used as a light harvesting antenna and subsequent excited state energy transfer populates the emitting lanthanide centred excited state. A rudimentary understanding of the design criteria for designing efficient dyes and assays based on the antenna effect is in place. By preparing kinetically inert lanthanide complexes based on the DO3A scaffold, we are able to study the excited state energy transfer from a 7-methoxy-coumarin antenna chromophore to europium(iii) and terbium(iii) centred excited states. By contrasting the photophysical properties of complexes of metal centres with and without accessible excited states, we are able to separate the contributions from the heavy atom effect, photoinduced electron transfer quenching, excited state energy transfer and molecular conformations. Furthermore, by studying the photophysical properties of the antenna chromophore, we can directly monitor the solution structure and are able to conclude that excited state energy transfer from the chromophore singlet state to the lanthanide centre does occur.
基于镧系元素的染料及分析方法利用了天线效应，即敏化剂-发色团被用作光捕获天线，随后的激发态能量转移使以镧系元素为中心的发射激发态得以填充。对于基于天线效应设计高效染料及分析方法的设计标准已有初步认识。通过制备基于DO3A支架的动力学惰性镧系配合物，我们能够研究从7-甲氧基香豆素天线发色团到以铕(III)和铽(III)为中心的激发态的激发态能量转移。通过对比具有和不具有可及激发态的金属中心配合物的光物理性质，我们能够区分重原子效应、光致电子转移猝灭、激发态能量转移和分子构象的贡献。此外，通过研究天线发色团的光物理性质，我们可以直接监测溶液结构，并能够得出结论：从发色团单重态到镧系元素中心的激发态能量转移确实发生。
