Structurally and electronically modulated spin interaction of transient biradicals in two photon-gated stepwise photochromism
Structurally and electronically modulated spin interaction of transient biradicals in two photon-gated stepwise photochromism
复制标题
两个光子门控逐步光致变色中瞬态双自由基的结构和电子调制自旋相互作用
DOI：
10.1039/c7pp00420f
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发表时间：
2018
影响因子：
3.1
通讯作者：
Abe Jiro
中科院分区：
文献类型：
--
作者：
Yonekawa Izumi;Mutoh Katsuya;Kobayashi Yoichi;Abe Jiro
双光子光致变色化合物的研究对于新型光响应材料的开发具有重要意义。利用长寿命的过渡态或物种进行双光子吸收是实现超越单光子光化学反应的高级光化学行为的有效策略之一。我们合成了由两个光致变色苯基-咪唑基络合物单元组成的双光致变色化合物。当两个光致变色单元以阶梯方式吸收光子时，双光致变色化合物产生两个双自由基单元。两个双自由基之间通过中心苯环的相互作用是控制分步光致变色反应的关键特征。在这里，我们引入了芳香间隔基，以调节双自由基单元之间的距离和二面角。通过对中心桥连部分的控制，可以调节阶跃光致变色的颜色和热逆反应速率。这些结果为开发理想的高级光响应化合物提供了重要的见解。
The development of two-photon induced photochromic compounds is important for advanced photo-responsive materials. The utilization of the long-lived transient states or species for two-photon absorption is one of the efficient strategies to realize the advanced photochemical behavior beyond a one-photon photochemical reaction. We have synthesized bi-photochromic compounds composed of two photochromic phenoxyl-imidazolyl radical complex units. The biphotochromic compounds generate two biradical units when the two photochromic units absorb photons with a stepwise manner. The interaction between the two biradicals through the central bridging phenyl ring is the key feature to control the step-wise photochromic reaction. Here, we introduced aromatic spacers in order to modulate the distance and the dihedral angle between the biradical units. The color and the rate of the thermal back reaction of the stepwise photochromism can be regulated by the control of the central bridging part. These results give important insights to develop desirable advanced photoresponsive compounds.