Preparation and Analyses of the Multifunctional Properties of 2D and 3D MOFs Constructed from Copper(I) Halides and Hexamethylenetetramine

Abstract

In this article, two two-dimensional and three-dimensional metal–organic frameworks are synthesized by the self-assembly of copper(I) halide and the hexamethylenetetramine (hmt) ligand. Compound 1 is a two-dimensional metal–organic framework composed of a pyramidal Cu 4 I 5 cluster and hexamethylenetetramine, in which hmt-bridged Cu clusters form a two-dimensional (4,4)-connected net with a point symbol of (4 4 ·6 2 ) (4 4 ·6 2 ). Compound 2 is a homochiral three-dimensional metal–organic framework material generated through an unusual spontaneous crystallization from achiral precursors. The two compounds were characterized by a series of analyses such as infrared spectroscopy, elemental analysis, circular dichroism spectroscopy, and powder X-ray diffraction. Both of them exhibit unexpected stability under a wide range of conditions of acid and base. In addition, the fluorescence intensity changes regularly under acid–base conditions. Stokes shift shows a good linear relationship with −log [H + ], which makes them become promising acid–base sensors. Compounds 1 and 2 also display selective adsorption and a significant degradation effect on the organic dye methylene blue. In addition, the fluorescence study indicated that compound 2 could be used as a sensor to detect Cr 3+ .

Ultrafast In Situ Synthesis of Large-Area Conductive Metal–Organic Frameworks on Substrates for Flexible Chemiresistive Sensing

“…Exposure to a large quantity of NH 3 will cause injuries to the skin, eyes, and respiratory tract. − In the biomedical field, NH 3 is also a natural body product produced in the human body by various metabolic activities, and an excessive amount of NH 3 in exhaled human breath can be treated as an indication of several diseases related to dysfunctions of the liver and kidneys. , Therefore, the development of high-performance NH 3 sensors is of great significance in biomedical and environmental fields. As a result of the high surface/volume ratio and intrinsic conductivity, EC-MOFs are widely used in gas sensing. − In particular, the use of EC-MOFs in NH 3 sensors has been intensively investigated in an effort to exploit their metal nodes and ligands to enhance surface reactions and adsorption of gas molecules. − However, sensing mechanisms based on EC-MOFs are rather complicated, and the contributions of surface morphology and crystal defects to the sensing performance have rarely been identified. For patients to detect the concentration of NH 3 in their breath at home, an ultrasensitive and highly selective sensor is required to detect a small amount of NH 3 in real time at low driving voltages. , With the development of wearable devices, the sensor is also required to be flexible and stretchable to maintain performance under possible deformations originating from the movement of the skin or body.…”

Selective and Multicyclic CO2 Adsorption with Visible Light-Driven Photodegradation of Organic Dyes in a Robust Metal–Organic Framework Embracing Heteroatom-Affixed Pores

“…However, the rate of the reaction decelerating beyond 40 min can be attributed to 51 and 64% degradation of CV and MB, respectively, representing the first-order kinetics. , Nearly 97.2% of CV and 97.8% of MB dye solution degraded after a time span of 120 min, and the solution turned colorless in both the cases (inset of Figure a,b). The degradation efficiency is mainly determined by the free carrier available on the surface of the photocatalysts. − Although exact comparison of dye photodegradation efficacy with other MOFs is difficult because of the diverse degrees of photocatalyst concentration, dye concentration, oxidants, and/or intensity of the light source, the degradation efficiencies in the present framework are superior to those of many of the transition metal-based MOFs (Table S4). To gain deeper insights into the kinetics of degradation, the experimental data were fitted using the Langmuir–Hinshelwood model (eq ) mentioned below. here, C 0 is the initial concentration of the dye; C is the concentration of the dye at the respective irradiation time ( t ); and k is the pseudo-first-order kinetic constant (the slope of the linear range of the plot).…”

Identifying biochemical constituents involved in the mycosynthesis of zinc oxide nanoparticles

“…25 Second, there are numerous reports of HMTA functioning to bind metal cations and form nanomaterials such as metal organic frameworks in a non-biological context. [40][41][42][43][44][45][46][47][48] As previously described, many reports on the biosynthesis of NPs either challenge the bacteria, fungi, yeast, or leaf extract directly with metal salts, or spike the resulting exudates after the organismal component has been removed. 21,39 In our previous work, we challenged the fungus with various Zn salts and subsequently spiked the cell-free exudate with Zn salts as well.…”