Three Novel Isomeric Zinc Metal–Organic Frameworks from a Tetracarboxylate Linker

Abstract

Three porous supramolecular isomers (IZE-1, IZE-2, and IZE-3) with the same framework component [Zn(2)(EBTC)(H(2)O)(2)] (EBTC = 1,1'-ethynebenzene-3,3',5,5'-tetracarboxylate) were successfully constructed by finely tuning the reaction condition. Although both IZE-1 and IZE-2 are constructed from the linear EBTC subunits and one kind of regular [Zn(2)(CO(2))(4)] paddlewheels, their frameworks exhibit two different (3,4)-c net of fof (sqc1575) and sqc1572, respectively, resulting in cavities with different size and shape. However, as for isomer IZE-3, the EBTC ligands are bent and one-half of the [Zn(2)(CO(2))(4)] paddlewheels are distorted, leading to a novel (3,4,4)-c hyx net with point symbol (6.7(2))(4)(6(2).8(2).10(2))(7(2).8(2).11(2)) and vertex symbol (6.7.7)(4)(7(2).7(2).8.8.12.12)(6.6.8.8.10(2).10(2)). Quantum chemical calculations by DFT indicate that the three isomers have very close thermodynamic stabilities, which may explain that subtle condition change leads to variation of the frameworks. Further theoretical semiempirical investigation on the interactions between solvent molecules and compounds shows different hydrogen binding patterns in good agreement with the experimental observations. Furthermore, they exhibit good solid-state luminescence properties with long lifetime.

An Electroactive Zinc-based Metal–Organic Framework: Bifunctional Fluorescent Quenching Behavior and Direct Observation of Nitrobenzene

“…Strands of the framework of 1 (Figure b) are interwoven with each other, resulting in the formation of a robust framework. A topology analysis indicates that 1 (Figure c) possesses a 3,4,4-c connected net − where the TTPA ligand acts as a three-connecting node and two independent Zn­(II) metal ions act as a four-connecting node for both metal ions. The Schläfli symbol of 1 is represented as (4.8.10) 2 (4.8 2 .10 3 ) 2 (8 2 .10 2 .11 2 ).…”

Metallacarborane-Based Metal–Organic Framework with a Complex Topology

“…Furthermore, we will seek to expand the chemistry of these linkers to other metal centers. For example, it has also been shown that tetracarboxy linkers when combined with zinc paddlewheels generate novel topologies along with the standard fof topology. , With this in mind we are investigating the combination of novel redox-active polytopic metallacarborane-based linkers with a variety of metal-based nodes in order to generate new families of stimuli-responsive MOFs with new properties and topologies for use in areas such as ion exchange, gas separation, and energy storage.…”

MOF-Derived Flower-like MoS2@TiO2 Nanohybrids with Enhanced Activity for Hydrogen Evolution

“…To the best of our knowledge, no relevant work has been reported for the application of metal–organic frameworks (MOFs) as precursors to synthesize MoS 2 /TiO 2 nanohybrid catalysts for HER. MOFs are crystalline materials composed of metal nodes and ligand spacers, which have a wide range of applications including gas storage, electrochemical capacitors, lithium ion batteries, molecular separation, catalysis, imaging, sensing, and drug delivery, etc. − Recently, MOFs-derived catalysts continue to capture plenty of attention for the following reasons. , First, the regular arrangement of each component in MOF always leads to homogeneous hybrids. Second, the well-aligned and tunable pores in MOF can result in uniform porous materials, which facilitate the mass transport and the products release, allowing high utilization of active species .…”