Introduction 836 1.1. Background and History 836 1.2. Examples of Commensurate Adsorption of Hydrocarbons 836 2. Hydrocarbon Adsorption in MMOFs 838 2.1. Gas Adsorption and Adsorptive Separation 838 2.2. Selective Adsorption of Hydrocarbons in MMOFs 842 2.3. Adsorption: Methods and Characterization 844 2.3.1. Experimental Methods 844 2.3.2. Modeling and Simulations 844 2.3.3. Physical Properties of Adsorbates 845 3. Commensurate Adsorption of Hydrocarbons in MMOFs 845 3.1. Crystal and Pore Structures 845 3.2. Commensurate Adsorption in Selected MMOFs 846 3.2.1. [M 3 (fa) 6 ] 3 sol (M = Mg, Mn, Co, Ni) 846 3.2.2. [Cu(hfipbb)(H 2 hfipbb) 0.5 ] 848 3.2.3. [Cu 2 (pzdc) 2 (pyz)] 3 2H 2 O 848 3.2.4. Al 12 O(OH) 18 (H 2 O) 3 (Al 2 (OH) 4 )[btc] 6 3 24H 2 O (MIL-96) 849 3.2.5. [Zn 2 (bpdc) 2 (bpee)] 3 2DMF (RPM3-Zn) 852 3.2.6. [Zn 2 (bpdc) 2 (bpe)] 3 2DMF (RPM4-Zn) 853 3.2.7. [V IV O(bdc)] (MIL-47) 854 3.2.8. [M III (OH)(bdc)] (M = Al, Cr, Fe and Ga) (MIL-53) 856 4. Commensurate Adsorption in Other Porous Structures 859 4.1. [Cu(dhbc) 2 (4,4 0 -bpy)] 3 H 2 O 859 4.2. [Cd 3 (btb) 2 (DEF) 4 ] 3 2DEF 860 5. Concluding Remarks 861 Author Information 861 Biographies 861 Acknowledgment 862 List of Abbreviations 862 References 863 dx.

Instability of most prototypical metal organic frameworks (MOFs) in the presence of moisture is always a limitation 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 susceptible 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 determining operation conditions of this class of MOFs with paddle wheel secondary building units and guidance for developing more robust units.

Microporous metal-organic frameworks (MOFs) have attracted tremendous attention because of their versatile structures and tunable porosity that allow almost unlimited ways to improve their properties and optimize their functionality, making them very promising for a variety of important applications, especially in the adsorption and separation of small gases and hydrocarbons. Numerous studies have demonstrated that MOFs with multifunctional groups, such as open metal sites (OMSs) and Lewis basic sites (LBSs), interact strongly with carbon dioxide and are particularly effective in its capture and separation from binary mixtures of CO(2) and N(2). In this feature article, we briefly review the current state of MOF development in this area, with an emphasis on the effect of multifunctional groups on the selectivity and capacity of MOFs for the CO(2) capture from flue gas mixtures.

Water dissociation represents one of the most important reactions in catalysis, essential to the surface and nano sciences [e.g., Hass et al., Science, 1998, 282, 265-268; Brown et al., Science 2001, 294, 67-69; Bikondoa et al., Nature 2005, 5, 189-192]. However, the dissociation mechanism on most oxide surfaces is not well understood due to the experimental challenges of preparing surface structures and characterizing reaction pathways. To remedy this problem, we propose the metal organic framework MOF-74 as an ideal model system to study water reactions. Its crystalline structure is well characterized; the metal oxide node mimics surfaces with exposed cations; and it degrades in water. Combining in situ IR spectroscopy and first-principles calculations, we explored the MOF-74/water interaction as a function of vapor pressure and temperature. Here, we show that, while adsorption is reversible below the water condensation pressure (~19.7 Torr) at room temperature, a reaction takes place at ~150 ˚C even at low water vapor pressures. This important finding is unambiguously demonstrated by a clear spectroscopic signature for the direct reaction using D 2 O, which is not present using H 2 O due to strong phonon coupling. Specifically, a sharp absorption band appears at 970 cm -1 when D 2 O is introduced at above 150 ˚C, which we attribute to an O-D bending vibration on the phenolate linker. Although H 2 O undergoes a similar dissociation reaction, the corresponding O-H mode is too strongly coupled to MOF vibrations to detect. In contrast, the O-D mode falls in the phonon gap of the MOF and remains localized. First-principles calculations not only positively identify the O-D mode at 970 cm -1 but derive a pathway and kinetic barrier for the reaction and the final configuration: the D (H) atom is transferred to the oxygen of the linker phenolate group, producing the notable O-D absorption band at 970 cm -1 , while the OD (or OH) binds to the open metal sites. This finding explains water dissociation in this case and provides insight into the long-lasting question of MOF-74 degradation. Overall, it adds to the understanding of molecular water interaction with cation-exposed surfaces to enable development of more efficient catalysts for water dissociation.2

We designed and synthesized a new luminescent metal-organic framework (LMOF). LMOF-241 is highly porous and emits strong blue light with high efficiency. We demonstrate for the first time that very fast and extremely sensitive optical detection can be achieved, making use of the fluorescence quenching of an LMOF material. The compound is responsive to Aflatoxin B1 at parts per billion level, which makes it the best performing luminescence-based chemical sensor to date. We studied the electronic properties of LMOF-241 and selected mycotoxins, as well as the extent of mycotoxin-LMOF interactions, employing theoretical methods. Possible electron and energy transfer mechanisms are discussed.