Intramolecular energy transfer in pyrene-bodipy molecular dyads and triads.
Intramolecular energy transfer in pyrene-bodipy molecular dyads and triads.
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DOI：
10.1002/chem.200500373
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发表时间：
2005-12
期刊：
影响因子：
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通讯作者：
R. Ziessel;C. Goze;G. Ulrich;M. Césario;P. Retailleau;A. Harriman;James P. Rostron
中科院分区：
文献类型：
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作者：
R. Ziessel;C. Goze;G. Ulrich;M. Césario;P. Retailleau;A. Harriman;James P. Rostron
以基于钯（0）促进的交叉偶联反应的分步方法，用所需的预构建模块构建了具有4，4-二氟-8-（芳基）-1，3，5，7-四甲基-2，6-二乙基-4-硼杂-3a，4a-二氮杂-s-引达省（bodipy）核和1-芘基-1-苯基-4-（1-乙炔基芘）或1-苯基-4-[1-乙炔基-（6-乙炔基芘）芘]单元的分子。单晶的X射线结构揭示了两个发色团的扭曲排列。在一种情况下，一个几乎完美的正交arrangement. These染料是在溶液中强烈发光，并显示丰富的电化学，其中所有的氧化还原过程的bodipy和芘片段清楚地解决。吸收光谱表明，bodipy和pyrene发色团在光谱上是分离的，从而引起了大的“虚拟”斯托克斯位移。后者通过福斯特偶极-偶极机制有效转移分子内激发能来实现。能量转移的速率取决于双染料系统的结构，并且随着中心到中心分离的增加而降低。然而，在所有情况下，能量转移效率超过90%。两个芘残基通过乙炔基连接导致能量转移效率降低，两个多环充当单个发色团。直接连接的二苯并芘-芘双染料与DNA结合，分散在塑料中时可作为有效的太阳能集中器。
Molecules bearing a 4,4-difluoro-8-(aryl)-1,3,5,7-tetramethyl-2,6-diethyl-4-bora-3a,4a-diaza-s-indacene (bodipy) core and 1-pyrenyl-1-phenyl-4-(1-ethynylpyrene), or 1-phenyl-4-[1-ethynyl-(6-ethynylpyrene)pyrene] units were constructed in a step-by-step procedure based on palladium(0)-promoted cross-coupling reactions with the required preconstructed modules. X-ray structures of single crystals reveal a twisted arrangement of the two chromophores. In one case, an almost perfect orthogonal arrangement is found. These dyes are strongly luminescent in solution and display rich electrochemistry in which all redox processes of the bodipy and pyrene fragments are clearly resolved. The absorption spectra indicate that the bodipy and pyrene chromophores are spectrally isolated, thereby inducing a large "virtual" Stokes shift. The latter is realised by efficient transfer of intramolecular excitation energy by the Förster dipole-dipole mechanism. The rate of energy transfer depends on the structure of the dual-dye system and decreases as the centre-to-centre separation increases. The energy transfer efficiency, however, exceeds 90 % in all cases. The linkage of two pyrene residues by an ethyne group leads to a decrease in the energy-transfer efficiency, with the two polycycles acting as a single chromophore. The directly linked bodipy-pyrene dual dye binds to DNA and operates as an efficient solar concentrator when dispersed in plastic.