Chen Cheng-Xia, Yin Shao-Yun, Wei Zhang-Wen, Qiu Qian-Feng, Zhu Neng-Xiu, Fan Ya-Nan, Pan Mei, Su Cheng-Yong
MOE Laboratory of Bioinorganic and Synthetic Chemistry, Lehn Institute of Functional materials, School of Chemistry, Sun Yat-Sen University, Guangzhou, 510275, China.
Angew Chem Int Ed Engl. 2019 Oct 1;58(40):14379-14385. doi: 10.1002/anie.201908793. Epub 2019 Aug 19.
In multiphoton excited fluorescence (MPEF), high-energy upconversion emission is obtained from low-energy excitation by absorbance of two or more photons simultaneously. In a pressure-induced fluorochromic process, the emission energy is switched by outer pressure stimuli. Now, five metal-organic frameworks containing the same ligand with simultaneous multiphoton absorption and pressure-induced fluorochromic attributes were studied. One-, two-, and three-photon excited fluorescence (1/2/3PEF) can be achieved in the frameworks, which exhibit pressure-induced blue-to-yellow fluorochromism. The performances are closely dependent with the topologies, flexibilities, and packing states of the frameworks and chromophores therein. The multiphoton upconversion performance can be intensified by pressure-related structural contraction. Over ten-fold increment in the 2PA active cross-section up to 2217 GM is achieved in pressed LIFM-114 compared with the 210 GM for pristine sample at 780 nm.
在多光子激发荧光（MPEF）中，通过同时吸收两个或更多光子，从低能量激发获得高能上转换发射。在压力诱导的荧光变色过程中，发射能量由外部压力刺激切换。现在，研究了五种含有相同配体的金属有机框架，它们具有同时的多光子吸收和压力诱导的荧光变色特性。在这些框架中可以实现单光子、双光子和三光子激发荧光（1/2/3PEF），它们表现出压力诱导的蓝到黄荧光变色。这些性能与框架及其内发色团的拓扑结构、柔韧性和堆积状态密切相关。与压力相关的结构收缩可以增强多光子上转换性能。与原始样品在780nm处的210GM相比，压制后的LIFM-114在2PA活性截面中实现了超过十倍的增量，高达2217GM。
