Stability and Hydrolyzation of Metal Organic Frameworks with Paddle-Wheel SBUs upon Hydration

Instability of most prototypical metal organic frameworks (MOFs) in the presence of moisture is always a limita- tion for industrial scale development. In this work, we examine the dissociation mechanism of microporous paddle wheel frameworks M(bdc)(ted)0.5 [M=Cu, Zn, Ni, Co; bdc= 1,4-benzenedicarboxylate; ted= triethylenediamine] in controlled humidity environments. Combined in-situ IR spectroscopy, Raman, and Powder x-ray diffraction measurements show that the stability and modification of isostructual M(bdc)(ted)0.5 compounds upon exposure to water vapor critically depend on the central metal ion. A hydrolysis reaction of water molecules with Cu-O-C is observed in the case of Cu(bdc)(ted)0.5. Displacement reactions of ted linkers by water molecules are identified with Zn(bdc)(ted)0.5 and Co(bdc)(ted)0.5. In contrast,. Ni(bdc)(ted)0.5 is less suscept- ible to reaction with water vapors than the other three compounds. In addition, the condensation of water vapors into the framework is necessary to initiate the dissociation reaction. These findings, supported by supported by first principles theoretical van der Waals density functional (vdW-DF) calculations of overall reaction enthalpies, provide the necessary information for de- termining operation conditions of this class of MOFs with paddle wheel secondary building units and guidance for developing more robust units

Tetrathiafulvalene-Based Magnets of Lanthanides

International audienceTetrathiafulvalene (TTF)-based ligands and lanthanide ions have been intensively used for their electronic conductivity and optical properties, respectively. Their combination leads to a new class of coordination compounds that are able to display single-molecule magnet (SMM) behavior. Magnetic bistability resulting of such behavior could find potential applications in high-density data storage and quantum computing. In this chapter, a library of TTF-based magnets containing lanthanide ions is presented. Among this series, the influence of the coordination sphere and intra- and intermolecular interactions such as exchange, dipolar, supramolecular, and hyperfine interactions is probed through molecular engineering, magnetic dilutions, and isotopic enrichment