Kamal Samrah, Khalid Mohd, Khan M Shahnawaz, Shahid M, Ahmad Musheer
Functional Inorganic Materials Lab (FIML), Department of Chemistry, Aligarh Muslim University, Aligarh, 202002, India.
Pillar of Engineering Product Development, Singapore University of Technology and Design, 8 Somapah Road, 487372, Singapore.
Dalton Trans. 2023 Apr 4;52(14):4501-4516. doi: 10.1039/d3dt00237c.
A 2-dimensional Pb(II) metal-organic framework, [Pb(bdc)(py-Phen)NO] (SM-3), was synthesized under solvothermal conditions using a mixed ligand approach. SM-3 was assembled using dinuclear SBUs [Pb(COO)], an oxygen donor Hbdc = 1,4-benzene dicarboxylic acid, and nitrogen donor py-Phen = pyrazino[2,3-][1,10]-phenanthroline linkers. SM-3 was characterized by elemental analysis, FT-IR, powder-X-ray diffraction, thermal gravimetric analysis, SEM, EDS, TEM, and single-crystal X-ray diffraction techniques. Crystallographic studies confirmed that SM-3 displays a 2D layered structure with unique anagostic (Pb⋯H) interactions. Interestingly, the presence of abundant π-electron-rich rings embellished with free -N donor sites in the framework makes SM-3 an excellent adsorbent that exhibits adsorption performance for iodine and dyes. The experimental results show that SM-3 reversibly adsorbs radioactive iodine in the solution and vapor phases and exhibits selective adsorption performance for hazardous cationic dyes, namely, methylene blue (MB) and rhodamine-B (Rh-B), from aqueous solution. Moreover, the possible mechanism of iodine and dye adsorption was also discussed in detail. Thus, this work is remarkable for coordination chemists to engineer layered MOFs for adsorption purposes and expands their potential characteristics by converting them into 2D MOF nanosheets to further enhance the adsorption of hazardous pollutants for environment protection.
采用混合配体法在溶剂热条件下合成了二维铅（II）金属有机骨架化合物[Pb(bdc)(py-Phen)NO]（SM-3）。SM-3由双核次级构筑单元[Pb(COO)]、氧供体Hbdc = 1,4-苯二甲酸和氮供体py-Phen = 吡嗪并[2,3-][1,10]-菲咯啉连接体组装而成。通过元素分析、傅里叶变换红外光谱、粉末X射线衍射、热重分析、扫描电子显微镜、能谱分析、透射电子显微镜和单晶X射线衍射技术对SM-3进行了表征。晶体学研究证实，SM-3呈现二维层状结构，具有独特的（Pb⋯H）次级相互作用。有趣的是，骨架中存在大量富含π电子且带有游离氮供体位点的环，这使得SM-3成为一种优异的吸附剂，对碘和染料具有吸附性能。实验结果表明，SM-3在溶液相和气相中可逆地吸附放射性碘，并对水溶液中的有害阳离子染料，即亚甲基蓝（MB）和罗丹明B（Rh-B）表现出选择性吸附性能。此外，还详细讨论了碘和染料吸附的可能机理。因此，这项工作对于配位化学家设计用于吸附目的的层状金属有机骨架化合物具有重要意义，并通过将其转化为二维金属有机骨架纳米片来扩展其潜在特性，以进一步增强对有害污染物的吸附，从而保护环境。
