Chakraborty Gouri, Das Prasenjit, Mandal Sanjay K
Department of Chemical Sciences, Indian Institute of Science Education and Research Mohali, Sector 81, Manauli PO, S.A.S. Nagar, Mohali, Punjab 140306, India.
ACS Appl Mater Interfaces. 2020 Mar 11;12(10):11724-11736. doi: 10.1021/acsami.9b22658. Epub 2020 Feb 26.
A rational combination of an oxygen-rich pyridyl substituted tetrapodal ligand, tetrakis(4-pyridyloxymethylene)methane (TPOM), and a polar sulfone-functionalized conjugated bent dicarboxylate linker, dibenzothiophene-5,5'-dioxide-3,7-dicarboxylic acid (H(3,7-DBTDC)), with d metal centers, Zn(II) and Cd(II), has led to the construction of two new three-dimensional (3D) metal-organic frameworks,{[Zn(TPOM)(3,7-DBTDC)]·7HO·DMA} () and {[Cd(TPOM)(3,7-DBTDC)]·6HO·3DMF} (). Single-crystal X-ray analysis indicates that is a 3D framework with a dinuclear repeating unit having two different Zn(II) centers (tetrahedral and square pyramidal) and is a 3D framework comprised of a dinuclear repeating unit with one crystallographically independent distorted pentagonal bipyramidal Cd(II) coordinated to chelating/bridging carboxylates and nitrogen atoms of the TPOM ligand. In both cases, the pores are aligned with oxygen atoms of the TPOM ligand and decorated with polar sulfone moieties. On the basis of the stability established by thermogravimetric analysis and powder X-ray diffraction (PXRD) and the presence of large solvent accessible voids (25.4% for and 40.6% for ), gas sorption studies of different gases (N, CO, and CH) and water vapor have been explored for both and . The CO sorption isotherm depicts type I isotherm with an uptake of 93.6 cm g (for ) and 100.6 cm g (for ) at 195 K. Additionally, sorption of CO is highly selective over that of N and CH for both and due to the strong quadrupolar interactions between sulfone moieties and CO molecules. Configurational bias Monte Carlo (CBMC) molecular simulation has further justified the highly selective CO capture. On the other hand, the luminescence nature of and has been employed for highly selective detection of acetylacetone in aqueous methanol with a limit of 59 ppb in and 66 ppb in , which are among the best reported values so far in the literature. The Stern-Volmer plots, spectral overlap, density functional theory calculations, CBMC simulation, and time-resolved lifetime measurements have been utilized for an extensive mechanistic study. The exclusive selectivity for acetylacetone in and have been confirmed by competitive selectivity test. Both exhibited good recyclability and stability after sensing experiments analyzed by fluorescence, PXRD, and field emission scanning electron microscopy studies.
一种富含氧的吡啶基取代四足配体四（4 - 吡啶氧基甲基）甲烷（TPOM）与一种极性砜官能化共轭弯曲二羧酸连接体二苯并噻吩 - 5,5'-二氧化物 - 3,7 - 二羧酸（H(3,7 - DBTDC)）与d金属中心锌（II）和镉（II）的合理组合，导致构建了两个新的三维（3D）金属有机框架，{[Zn(TPOM)(3,7 - DBTDC)]·7H₂O·DMA}（）和{[Cd(TPOM)(3,7 - DBTDC)]·6H₂O·3DMF}（）。单晶X射线分析表明是一个具有双核重复单元的3D框架，该单元有两个不同的锌（II）中心（四面体和四方锥），并且是一个由双核重复单元组成的3D框架，其中一个晶体学独立的扭曲五角双锥镉（II）与TPOM配体的螯合/桥连羧酸盐和氮原子配位。在这两种情况下，孔都与TPOM配体的氧原子对齐，并装饰有极性砜部分。基于热重分析和粉末X射线衍射（PXRD）确定的稳定性以及大的溶剂可及空隙的存在（对于为25.4%，对于为40.6%），对和都进行了不同气体（N₂、CO₂和CH₄）以及水蒸气的气体吸附研究。CO₂吸附等温线描绘为I型等温线，在195 K时的吸附量为93.6 cm³ g⁻¹（对于）和100.6 cm³ g⁻¹（对于）。此外，由于砜部分与CO₂分子之间的强四极相互作用，对于和，CO₂的吸附相对于N₂和CH₄具有高度选择性。构型偏差蒙特卡罗（CBMC）分子模拟进一步证明了对CO₂的高度选择性捕获。另一方面，和的发光性质已被用于在甲醇水溶液中对乙酰丙酮进行高选择性检测，在中的检测限为59 ppb，在中的检测限为66 ppb，这是迄今为止文献中报道的最佳值之一。已利用斯特恩 - 沃尔默图、光谱重叠、密度泛函理论计算、CBMC模拟和时间分辨寿命测量进行了广泛的机理研究。通过竞争性选择性测试证实了对乙酰丙酮的排他选择性。在通过荧光、PXRD和场发射扫描电子显微镜研究分析传感实验后，两者都表现出良好的可回收性和稳定性。
