Uniquely shaped double-decker buckyferrocenes--distinct electron donor-acceptor interactions.
Uniquely shaped double-decker buckyferrocenes--distinct electron donor-acceptor interactions.
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DOI：
10.1021/ja8013902
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发表时间：
2008-11
影响因子：
15
通讯作者：
R. Marczak;Mateusz Wielopolski;S. Gayathri;D. Guldi;Y. Matsuo;K. Matsuo;Kazukuni Tahara;E. Nakamura
中科院分区：
文献类型：
--
作者：
R. Marczak;Mateusz Wielopolski;S. Gayathri;D. Guldi;Y. Matsuo;K. Matsuo;Kazukuni Tahara;E. Nakamura
利用量子化学计算和各种光物理技术，从稳态吸收和稳态以及时间分辨荧光到飞秒泵浦-探测实验，研究了一组新型双层巴克二茂铁(即Fe(2)(C(60)Me(10))Cp(2))：C(2v)和D(5d)异构体的基态和激发态相互作用。与单个参照系相比，富勒烯/二茂铁的紧密接触反映了明显的基态相互作用，即两个电子给体(即二茂铁)和电子受体(即富勒烯)之间的电荷密度显著重新分布。此外，还建立了价间电荷转移转变(即二茂铁-二茂铁相互作用)，但仅在C(2v)异构体中。对电子给体-受体相互作用的第一次洞察来自于对富勒烯中心荧光的研究。相对于不含二茂铁的参考化合物，其量子产率高达0.1，并且知道所研究的双层型共轭化合物的荧光猝灭到10(-3)，瞬时吸收测量明确地证明了自由基离子对态的迅速形成是双层巴克二茂铁中激发态失活的主要产物。尽管与相应的单层巴克二茂铁相比，这些产品具有更高的自由基离子对状态，但它们的寿命在12到39 ps之间变化，略短。
Quantum chemical calculations and various photophysical techniques, ranging from steady-state absorption and steady-state as well as time-resolved fluorescence to femtosecond pump-probe experiments, were employed to examine ground- and excited-state interactions in a set of novel double-decker buckyferrocenes (i.e., Fe(2)(C(60)Me(10))Cp(2)): C(2v) and D(5d) isomers. When compared to the individual reference systems, the intimate fullerene/ferrocene contacts reflect appreciable ground-state interactions, namely, substantial redistribution of charge density between the two electron donors (i.e., ferrocenes) and the electron acceptor (i.e., fullerene). Furthermore, an intervalence charge-transfer transition (i.e., ferrocene-ferrocenium interaction) was established, but only in the C(2v) isomer. The first insight into the electron donor-acceptor interactions came from inspecting the fullerene-centered fluorescence. Relative to the reference compounds that contain no ferrocene, which exhibit quantum yields of up to 0.1, and knowing that the fluorescence of the investigated double-decker type conjugates is quenched to 10(-3), transient absorption measurements prove unequivocally the rapid formation of the radical ion-pair states as the dominant products of excited-state deactivation in the double-decker buckyferrocenes. Despite these products having much higher lying radical ion-pair states relative to the corresponding single-decker buckyferrocene, their lifetimes, which vary between 12 and 39 ps, are slightly shorter.