De Ankita, Haldar Sattwick, Schmidt Johannes, Amirjalayer Saeed, Reichmayr Fanny, Lopatik Nikolaj, Shupletsov Leonid, Brunner Eike, Weidinger Inez M, Schneemann Andreas
Inorganic Chemistry I, Technische Universität Dresden, Bergstr. 66, 01069, Dresden, Germany.
Department of Chemistry, Functional Materials, Technische Universität Berlin, Hardenbergstraße 40, 10623, Berlin, Germany.
Angew Chem Int Ed Engl. 2024 Jul 29;63(31):e202403658. doi: 10.1002/anie.202403658. Epub 2024 Jun 30.
The high degree of corrosivity and reactivity of bromine, which is released from various sources, poses a serious threat to the environment. Moreover, its coexistence with iodine forming an equilibrium compound, iodine monobromide (IBr) necessitates the selective capture of bromine from halogen mixtures. The electrophilicity of halogens to π-electron rich structures enabled us to strategically design a covalent organic framework for halogen capture, featuring a defined pore environment with localized sorption sites. The higher capture capacity of bromine (4.6 g g) over iodine by ~41 % shows its potential in selective capture. Spectroscopic results uncovering the preferential interaction sites are supported by theoretical investigations. The alkyne bridge is a core functionality promoting the selectivity in capture by synergistic physisorption, rationalized by the higher orbital overlap of bromine due to its smaller atomic size as well as reversible chemical interactions. The slip stacking in the structure has further promoted this phenomenon by creating clusters of molecular interaction sites with bromine intercalated between the layers. The inclusion of unsaturated moieties, i.e. triple bonds and the complementary pore geometry offer a promising design strategy for the construction of porous materials for halogen capture.
从各种来源释放出的溴具有高度腐蚀性和反应性，对环境构成严重威胁。此外，它与碘共存形成平衡化合物一溴化碘（IBr），这就需要从卤素混合物中选择性捕获溴。卤素对富含π电子结构的亲电性使我们能够战略性地设计一种用于捕获卤素的共价有机框架，其具有明确的孔环境和局部吸附位点。溴的捕获容量（4.6 g g）比碘高约41%，这表明其在选择性捕获方面具有潜力。揭示优先相互作用位点的光谱结果得到了理论研究的支持。炔桥是通过协同物理吸附促进捕获选择性的核心功能基团，这可归因于溴因其较小的原子尺寸而具有更高的轨道重叠以及可逆的化学相互作用。结构中的滑移堆积通过形成分子相互作用位点簇并使溴插层在层间，进一步促进了这种现象。不饱和部分（即三键）的引入以及互补的孔几何结构为构建用于捕获卤素的多孔材料提供了一种有前景的设计策略。
