Tetra(4-imidazoylphenyl)ethylene based metal-organic frameworks for highly selective detection of TNP and Fe3+

Tetraphenylpyrazine-Based Manganese Metal–Organic Framework as a Multifunctional Sensor for Cu2+, Cr3+, MnO4–, and 2,4,6-Trinitrophenol and the Construction of a Molecular Logical Gate

“…During the past decades, metal–organic frameworks (MOFs) emerged as a new type of inorganic–organic hybrid porous material and gained extensive attention because of their attractive properties including high specific surface area, tunable porosity, structural diversity, promising luminescence, etc. − Generally, MOFs were architected by a self-assembly process of metal ions and organic ligands using a hydrothermal method, and the topological structure and luminescent properties keep great relationships with the components of MOFs, such as the organic linker and metal node. , Thus, various ligands have been explored for architecting MOFs with the aim of obtaining a desired topological structure as well as improving the sensing properties. Among those organic linkers, poly­(carboxylic acid)­s attract much attention because of their attractive coordination diversities, which may facilitate the construction of attractive topological structures. ,− Besides, some other organic compounds with coordinated N atoms have also been designed and developed as linkers, for example, pyridine, imidazole, and triazole. ,,, Among these, multiimidazole-functionalized organic linkers were commonly used in MOF construction and produced interestingly and easily predicable topological structures because of their relatively simple coordination modes. − It is noted that functionalized tetraphenylpyrazine exhibit promising advantages in architecting MOF because the built-in Lewis N sites of pyrazine and the luminescent nature of tetraphenylpyrazine may facilitate their application in sensor design. ,− However, the utilization of multiimidazole-functionalized tetraphenylpyrazine for architecting MOF is seldom reported.…”

A Dihydrotetrazine-Functionalized Metal–Organic Framework as a Highly Selective Luminescent Host–Guest Sensor for Detection of 2,4,6-Trinitrophenol

“…Some functional groups such as −CH 3 are less interactive, but others such as −OH and −NH 2 are more interactive because they can participate in hydrogen bonding. In the case of −OH-substituted nitroaromatic molecules, few appropriate selectivities for phenolic NACs against −NH 2 -substituted NACs have been obtained − and, in the cases that high selectivity to phenolic NACs has been achieved, −NH 2 -substituted NACs were not investigated. ,− Also, in the case of −NH 2 -substituted nitroaromatic molecules, appropriate selectivity for −NH 2 substituted NACs in the presence of phenolic NACs has not been observed, − and in cases that high selectivities were reached, phenolic NACs were not investigated. − In contrast to what may come to mind at first, examples with high selectivity for phenolic − or −NH 2 -substituted NACs , in the presence of each other are rare. As a result of these facts, it is possible to say that few examples have been reported in which a MOF can detect a particular −OH- or −NH 2 -substituted NAC molecule or a specific group of substituted NACs with high selectivity in the presence of other NACs with similar structures, energy levels, and host–guest chemistry.…”

“…Also, TNP is the most acidic member of phenolic NACs in the order of TNP (p K a = 0.4), 2,4-dinitrophenol (DNP, p K a = 4.0), 4-nitrophenol (PNP, p K a = 7.16), and 2-nitrophenol (ONP, p K a = 7.24). , Moreover, TNP is a photoactive molecule and has a relatively strong absorption band at 300–450 nm. Investigations of published papers on the detection of TNP by MOFs have determined that in the many cases with selectivity tests, that between a TNP molecule and −NH 2 -substituted NACs (as serious interferers) was not explored ,− ,,,,− or poor selectivity was obtained when the TNP detection is investigated along with −NH 2 -substituted NACs. ,− A review of the literature shows that only rare examples have been successful in obtaining high TNP selectivity in the presence of −NH 2 -substituted NACs. ,,, These surprising and complex challenges in the selective detection of a specific group of substituted NACs, especially TNP, inspired us to investigate a way to solve this challenge using functional MOFs with optimized host–guest chemistry.…”

“…29,136−149 A review of the literature shows that only rare examples have been successful in obtaining high TNP selectivity in the presence of −NH 2 -substituted NACs. 74,75,77,150 These surprising and complex challenges in the selective detection of a specific group of substituted NACs, especially TNP, inspired us to investigate a way to solve this challenge using functional MOFs with optimized host−guest chemistry.…”

Controllable Synthesis of Metal–Organic Frameworks Based on Anthracene Ligands for High-Sensitivity Fluorescence Sensing of Fe3+, Cr2O72–, and TNP

“…22 Peng et al introduced two new 3D MOFs, showing excellent selectivity and sensitivity to picric acid (TNP). 23 For constructing multifunctional MOF materials, the selection of proper metal ions and organic ligands is very important. Here, there are two reasons to choose Cd 2+ as the metal center: (I) Cd 2+ belongs to d 10 metal ions with a variety of coordination numbers and geometric configurations and (II) Cd 2+ exhibits photoactivity when binding with luminescent ligands, 24 such as anthracene ligands.…”