Design of organic molecules with large two-photon absorption cross sections
Design of organic molecules with large two-photon absorption cross sections
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DOI：
10.1126/science.281.5383.1653
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发表时间：
1998-09-11
期刊：
影响因子：
56.9
通讯作者：
Xu, C
中科院分区：
文献类型：
--
作者：
Albota, M;Beljonne, D;Xu, C
基于以下概念，开发了一种设计具有大双光子吸收截面 δ 的分子的策略：在激发时，从共轭系统的末端到中间的对称电荷转移（反之亦然）与 δ 的增强值相关。具有供体-π-供体、供体-受体-供体和受体-供体-受体结构基序的合成双(苯乙烯基)苯衍生物表现出异常大的δ值，高达反式二苯乙烯的约400倍。对这些分子进行的量子化学计算表明，激发时会发生大量对称电荷重新分布，并提供与实验值非常一致的δ值。这里开发的分子所表现出的大增量和高荧光量子产率或三重态产率的结合分别为双光子荧光成像中前所未有的亮度或双光子敏化中增强的光敏度提供了潜力。
A strategy for the design of molecules with Large two-photon absorption cross sections, delta, was developed, on the basis of the concept that symmetric charge transfer, from the ends of a conjugated system to the middle, or vice versa, upon excitation is correlated to enhanced values of delta. Synthesized bis(styryl)benzene derivatives with donor-pi-donor, donor-acceptor-donor, and acceptor-donor-acceptor structural motifs exhibit exceptionally Large values of delta, up to about 400 times that of trans-stilbene. Quantum chemical calculations performed on these molecules indicate that substantial symmetric charge redistribution occurs upon excitation and provide delta values in good agreement with experimental values. The combination of Large delta and high fluorescence quantum yield or triplet yield exhibited by molecules developed here offers potential for unprecedented brightness in two-photon fluorescent imaging or enhanced photosensitivity in two-photon sensitization, respectively.