A Comprehensive Overview on Advanced Sensing Applications of Functional Metal Organic Frameworks (MOFs)

Disulfide Bonds as Functional Tethers in Metal-Organic Frameworks

The functionality of metal-organic frameworks (MOFs) is often encoded by specific chemical moieties found within these architectures. As such, new techniques to install increasingly more complex functionalities in MOFs are regularly being reported in the literature. One such functional group is the disulfide bond. The redox behavior of this covalent linkage renders MOFs responsive to stimuli, often under reducing conditions. Here, we review examples in which disulfide-containing MOFs are deployed in applications including drug delivery, therapeutic ferroptosis, exfoliation, energy storage, sensing, and others.

Metal-Organic Framework Coated Devices for Gas Sensing

The demand for monitoring chemical and physical information surrounding, air quality, and disease diagnosis has propelled the development of devices for gas sensing that are capable of translating external stimuli into detectable signals. Metal-organic frameworks (MOFs), possessing particular physiochemical properties with designability in topology, specific surface area, pore size and/or geometry, potential functionalization, and host-guest interactions, reveal excellent development promises for manufacturing a variety of MOF-coated sensing devices for multitudinous applications including gas sensing. The past years have witnessed tremendous progress on the preparation of MOF-coated gas sensors with superior sensing performance, especially high sensitivity and selectivity. Although limited reviews have summarized different transduction mechanisms and applications of MOF-coated sensors, reviews summarizing the latest progress of MOF-coated devices under different working principles would be a good complement. Herein, we summarize the latest advances of several classes of MOF-based devices for gas sensing, i.e., chemiresistive sensors, capacitors, field-effect transistors (FETs) or Kelvin probes (KPs), electrochemical, and quartz crystal microbalance (QCM)-based sensors. The surface chemistry and structural characteristics were carefully associated with the sensing behaviors of relevant MOF-coated sensors. Finally, challenges and future prospects for long-term development and potentially practical application of MOF-coated sensing devices are pointed out.

Glycols in the Synthesis of Zinc-Anilato Coordination Polymers

We report the synthesis, structural investigation, and thermal behavior for three zinc-based 1D-coordination polymers with 3,6-di-tert-butyl-2,5-dihydroxy-p-benzoquinone, which were synthesized in the presence of different glycols. The interaction of zinc nitrate with glycols, followed by using the resulting solution in solvothermal synthesis with the anilate ligand in DMF, makes it possible to obtain linear polymer structures with 1,2-ethylene or 1,2-propylene glycols coordinated to the metal. The reaction involving 1,3-propylene glycol under similar conditions gives a crystal structure that does not contain a diol. The crystal and molecular structures of the synthesized compounds were determined using single crystal by X-ray structural analysis. The influence of glycol molecules coordinated to the metal on the thermal destruction of synthesized compounds is shown.

Coordination polymers derived from alkali metal complexes of redox-active ligands

Treatment solutions of (dpp-bian)M (dpp-bian = 1,2-bis[(2,6-diisopropylphenyl)imino]acenaphthene; M = Li, Na, K) with 4,4′-bipyridine (4,4′-bipy) affords coordination polymers [(dpp-bian)M(4,4′-bipy)m]n, (M = Li or K, m = 1; M = Na, m = 2).