Excitation wavelength- and intensity-dependent stepwise two-photon-induced photochromic reaction
Excitation wavelength- and intensity-dependent stepwise two-photon-induced photochromic reaction
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激发波长和强度依赖的逐步双光子诱导光致变色反应
DOI：
10.1007/s43630-022-00234-y
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发表时间：
2022
期刊：
影响因子：
--
通讯作者：
Abe Jiro
中科院分区：
文献类型：
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作者：
Mutoh Katsuya;Yamamoto Katsuya;Abe Jiro
近年来，具有波长选择性或光强依赖性光响应的光致变色分子受到了越来越多的关注。虽然具有单个发色团的光开关可以控制功能的ON和OFF状态，但由多个发色团组成的光开关将用于复杂系统的特定控制。在此，我们设计了由两个不同的光致变色单元（PABI和PIC）组成的分步双光子诱导光致变色分子（PABI-PIC和PABI-PIC 2）。PABI-PIC在紫外光区的单光子吸收反应产生短暂的瞬态双自由基（BR），其以逐步的方式吸收可见光和紫外光区的额外光子以产生双光子光化学产物，醌类物质（Quinoid）。这些瞬态物种的光致变色性质在颜色和褪色速度上完全不同。此外，PABI-PIC还表现出依赖于激发波长的光致变色，因为PABI和PIC单元的激发态是电子正交的。因此，PABI-PIC的阶跃光致变色特性容易根据激发光强度和波长进行控制。这些分子设计对于开发先进的光响应材料非常重要。
The photochromic molecules showing wavelength-selective or light intensity-dependent photoresponse are receiving increased attention in recent years. Although a photoswitch with a single chromophore can control the ON and OFF states of a function, that consisting of multi-chromophores would be useful for the specific control in complex systems. Herein, we designed stepwise two-photon induced photochromic molecules (PABI–PIC and PABI–PIC2) consisting of two different photochromic units (PABI and PIC). One-photon absorption reaction in the UV light region of PABI–PIC generates the short-lived transient biradical (BR) that absorbs an additional photon in the visible and UV light region in a stepwise manner to produce the two-photon photochemical product, the quinoidal species (Quinoid). The photochromic properties of these transient species are completely different in color and fading speed. In addition, PABI–PIC also shows the excitation wavelength-dependent photochromism because the excited states of the PABI and PIC units are electronically orthogonal. Therefore, the stepwise photochromic properties of PABI–PIC are easily controlled depending on the excitation light intensity and wavelength. These molecular designs are important for the development of advanced photoresponsive materials.Graphical abstract