Wang Jun-Li, Liu Qiang, Meng Yin-Shan, Liu Xin, Zheng Hui, Shi Quan, Duan Chun-Ying, Liu Tao
State Key Laboratory of Fine Chemicals , Dalian University of Technology , 2 Linggong Rd. , 116024 , Dalian , China . Email:
Thermochemistry Laboratory , Liaoning Province Key Laboratory of Thermochemistry for Energy and Materials , Dalian National Laboratory for Clean Energy , Dalian Institute of Chemical Physics , Chinese Academy of Sciences , Dalian 116023 , China.
Chem Sci. 2018 Feb 5;9(11):2892-2897. doi: 10.1039/c7sc05221a. eCollection 2018 Mar 21.
Molecular materials possessing phototunable fluorescence properties have attracted great interest owing to their potential applications in optical switches and storage. However, most fluorescence modulation is realized through light-responsive structural isomerization in solution. It is a formidable challenge to achieve phototunable fluorescence emission with high fatigue resistance and a fast response rate in the solid state for the development of devices. Here, a mononuclear compound was constructed the coordination of fluorophores with Fe ions, whose electronic configuration changed from low spin to high spin upon light irradiation. The photoinduced spin crossover of Fe ions was accompanied by a 20% increase in the fluorescence emission intensity. A temperature-dependent spectroscopic study together with time-dependent density functional theory calculations revealed that the effective spectral overlap between the emission of the fluorophores and the absorption band of the Fe ions differed between the low spin and high spin states. The photoinduced spin crossover switched the energy transfer from the fluorophore to the Fe ion, resulting in fluorescence modulation. The presented results provide a novel approach for developing optical memory and sensors electron rearrangement of photoinduced spin crossover.
具有光可调荧光特性的分子材料因其在光开关和存储方面的潜在应用而备受关注。然而，大多数荧光调制是通过溶液中的光响应结构异构化实现的。对于器件开发而言，在固态中实现具有高抗疲劳性和快速响应速率的光可调荧光发射是一项艰巨的挑战。在此，通过荧光团与铁离子的配位构建了一种单核化合物，其电子构型在光照下从低自旋变为高自旋。铁离子的光致自旋交叉伴随着荧光发射强度增加20%。一项与时间相关的密度泛函理论计算相结合的温度相关光谱研究表明，荧光团发射与铁离子吸收带之间的有效光谱重叠在低自旋和高自旋状态下有所不同。光致自旋交叉将能量转移从荧光团切换到铁离子，从而导致荧光调制。所呈现的结果为通过光致自旋交叉的电子重排开发光学存储器和传感器提供了一种新方法。
