Excited state dynamics for visible-light sensitization of a photochromic benzil-subsituted phenoxyl-imidazolyl radical
Excited state dynamics for visible-light sensitization of a photochromic benzil-subsituted phenoxyl-imidazolyl radical
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DOI：
10.3762/bjoc.15.229
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发表时间：
2019-10
影响因子：
2.7
通讯作者：
Yoichi Kobayashi;Yukie Mamiya;Katsuya Mutoh;Hikaru Sotome;Masafumi Koga;H. Miyasaka;J. Abe
中科院分区：
文献类型：
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作者：
Yoichi Kobayashi;Yukie Mamiya;Katsuya Mutoh;Hikaru Sotome;Masafumi Koga;H. Miyasaka;J. Abe
可见光敏化光开关在生命科学和材料科学领域受到特别关注，因为长波长的光可以减少光降解，传输到物质内部深处，并在凝聚态系统中实现选择性激发。在各种光敏开关分子中，苯氧基咪唑基自由基配合物（phenoxyl-咪唑基radical complex， PIC）是近年来开发的一种热可逆的光致变色分子，通过合理设计分子结构，可以将热反反应时间从几十纳秒调整到几十纳秒。虽然PIC的开关速度的广泛可调范围开辟了各种潜在的应用，但对可见光的不光敏性限制了它的应用。在这项研究中，我们合成了一个可见光敏化的与苄基共轭的PIC衍生物。飞秒瞬态吸收光谱通过dexter型能量转移揭示了苯并基作为PIC单线态光敏剂的作用。PIC的可见光敏化光致变色反应对于扩大其在生命科学和材料科学中的潜在应用具有重要意义。
Visible-light sensitized photoswitches have been paid particular attention in the fields of life sciences and materials science because long-wavelength light reduces photodegradation, transmits deep inside of matters, and achieves the selective excitation in condensed systems. Among various photoswitch molecules, the phenoxyl-imidazolyl radical complex (PIC) is a recently developed thermally reversible photochromic molecule whose thermal back reaction can be tuned from tens of nanoseconds to tens of seconds by rational design of the molecular structure. While the wide range of tunability of the switching speed of PIC opened up various potential applications, no photosensitivity to visible light limits its applications. In this study, we synthesized a visible-light sensitized PIC derivative conjugated with a benzil unit. Femtosecond transient absorption spectroscopy revealed that the benzil unit acts as a singlet photosensitizer for PIC by the Dexter-type energy transfer. Visible-light sensitized photochromic reactions of PIC are important for expanding the versatility of potential applications to life sciences and materials science.