Xia Qing-Qing, Wang Xing-Huo, Yu Jia-Lin, Xue Zhi-Yuan, Chai Juan, Wu Ming-Xue, Liu Xiaomin
School of Chemistry and Chemical Engineering, Qingdao University, Qingdao 266071, Shandong, P. R. China.
Ningbo Institute of Materials Technology and Engineering, Chinese Academy of Sciences, 1219 Zhongguan West Road, Ningbo, Zhejiang 315201, P. R. China.
Dalton Trans. 2022 Jun 21;51(24):9397-9403. doi: 10.1039/d2dt00714b.
Luminescent metal-organic frameworks (MOFs) have garnered considerable attention in various fields. Herein, we proposed a hierarchical confinement strategy based on MOF-on-MOF to tune luminescence emission ranging from blue to red including white light in a flexible way. The easily available ZIF-8 MOF was used as a host for the confinement of two kinds of size-matching dyes (perylene and rhodamine B) to obtain a layered ZIF-8@dye@ZIF-8@dye encapsulation and seed-mediated synthesis. ZIF-8@dye@ZIF-8@dye materials with different fluorescence emission in dispersed and solid states were both obtained by tuning the initial encapsulation concentration of dye and changing the structure of the inner and outer ZIF-8@dye layers. To our delight, ZIF-8@0.125perylene@ZIF-8@25RhB with white light emission in the dispersed state was obtained; meanwhile, ZIF-8@0.125perylene + 25RhB and mechanically mixed ZIF-8@0.125perylene + ZIF-8@25RhB could not realize white light emission under the same conditions, indicating that the proposed hierarchical confinement strategy facilitated white light regulation. Similarly, the emission of ZIF-8@dye@ZIF-8@dye in the solid state has also been investigated; ZIF-8@perylene@ZIF-8@3RhB with white light emission was obtained, while white light emission could not be achieved in ZIF-8@perylene + 3RhB and ZIF-8@perylene + ZIF-8@3RhB, which further indicated the importance of the hierarchical confinement strategy based on MOF-on-MOF. The proposed hierarchical confinement strategy may also inspire the development of other functional optical MOF materials.
发光金属有机框架材料（MOFs）在各个领域都引起了相当大的关注。在此，我们提出了一种基于MOF-on-MOF的分级限域策略，以灵活地调节从蓝色到红色包括白光在内的发光发射。易于获得的ZIF-8 MOF被用作主体，用于限域两种尺寸匹配的染料（苝和罗丹明B），以获得分层的ZIF-8@染料@ZIF-8@染料封装和种子介导合成。通过调节染料的初始封装浓度以及改变内外ZIF-8@染料层的结构，均获得了在分散态和固态下具有不同荧光发射的ZIF-8@染料@ZIF-8@染料材料。令我们高兴的是，获得了在分散态下发射白光的ZIF-8@0.125苝@ZIF-8@25罗丹明B；同时，ZIF-8@0.125苝 + 25罗丹明B以及机械混合的ZIF-8@0.125苝 + ZIF-8@25罗丹明B在相同条件下无法实现白光发射，这表明所提出的分级限域策略有助于白光调控。同样，也对ZIF-8@染料@ZIF-8@染料在固态下的发射进行了研究；获得了发射白光的ZIF-8@苝@ZIF-8@3罗丹明B，而ZIF-8@苝 + 3罗丹明B和ZIF-8@苝 + ZIF-8@3罗丹明B无法实现白光发射，这进一步表明了基于MOF-on-MOF的分级限域策略的重要性。所提出的分级限域策略也可能会激发其他功能性光学MOF材料的开发。
