Photodynamics of a constrained parachute-shaped fullerene-porphyrin dyad
Photodynamics of a constrained parachute-shaped fullerene-porphyrin dyad
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受限降落伞形富勒烯-卟啉二元组的光动力学
DOI：
10.1021/ja992127y
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发表时间：
1999
影响因子：
15
通讯作者：
C. Luo
中科院分区：
文献类型：
--
作者：
D. Schuster;Peng Cheng;S. Wilson;V. Prokhorenko;M. Katterle;A. Holzwarth;S. Braslavsky;G. Klihm;René M. Williams;C. Luo
富勒烯C60作为电子和能量受体的显著能力导致了大量化合物的合成，其中C60共价连接到光活化基团上，这些基团可以作为潜在的给体。这类化合物作为光合作用反应中心的模型体系，由于C60和C60衍生物对单重态分子氧的高效光敏化作用，在光动力学治疗中也有潜在的应用。到目前为止，研究的此类系统中数量最多的是利用卟啉作为天线，在光谱的可见光区域有效地捕获光，以及各种连接物。光物理研究和分子模拟表明，在构象灵活的二元体中，由于堆积作用，卟啉(P)和C60部分非常接近，从而促进了通过空间的相互作用，如1P*荧光的猝灭和富勒烯激发态(通过能量转移)或P+-C60离子对状态(通过电子转移)的产生所证明的那样。2，4a，b，f-h这些离子对状态可以相对较长，这是由于较小的重组能量和用于背电子转移的强大热力学驱动力，这将该过程置于Marcus反转区域内。最近，人们的注意力集中在这样的刚性连接系统上，在这些系统中，卟啉(P)和(C60)部分被强制接近或被饱和的降冰糖或类固醇连接物强迫分开。作为了解P和C60生色团之间对话性质的计划的一部分，由于P-C60二联体的拓扑结构是系统变化的，我们现在报告降落伞状二联体1和相应的锌配合物1-锌的光物理数据。我们以前已经报道了通过Bingel-Hirsch将一种带环的丙二酸卟啉加成到C60上来合成1。
The pronounced ability of fullerene C60 to act as an electron and energy acceptor has led to the synthesis of a large number of compounds in which C60 is covalently linked to photoactivatable groups which can serve as potential donors. Such compounds are of interest as model systems for photosynthetic reaction centers and also have potential applications in photodynamic therapy because of the highly efficient photosensitization of singlet molecular oxygen formation by C60 and C60 derivatives. By far the largest number of such systems studied to date utilize porphyrins as antennas for efficient light capture in the visible region of the spectrum, and a variety of linkers. Photophysical studies as well as molecular modeling indicate that in conformationally flexible dyads the porphyrin (P) and C60 moieties are in close proximity, due to -stacking interactions, thus facilitating through-space interactions, as demonstrated by quenching of 1P* fluorescence and generation of fullerene-excited states (by energy transfer) or P+-C60- ion-pair states (by electron transfer).2,4a,b,f-h These ion-pair states can be relatively long-lived, due to the small reorganization energy and strong thermodynamic driving force for back-electron transfer, which places this process within the Marcus inverted region.4g, Recently attention has focused on rigidly linked systems in which the porphyrin (P) and (C60) moieties are in enforced close proximity or are forced apart by a saturated norbornylogous or steroid linker. As part of a program to understand the nature of the dialogue between P and C60 chromophores as the topology of P-C60 dyads is systematically varied, we now report photophysical data for the parachute-shaped dyad 1 and the corresponding zinc complex 1-Zn. We have reported previously the synthesis of 1 by Bingel-Hirsch addition of a strapped porphyrin malonate to C60.