A Metal−Organic Framework with Entatic Metal Centers Exhibiting High Gas Adsorption Affinity

A metal−organic framework, PCN-9, containing entatic metal centers, has been synthesized and crystallographically characterized. The H2 and CH4 adsorption enthalpies of PCN-9 are among the highest reported thus far

A Metal−Organic Framework with Entatic Metal Centers Exhibiting High Gas Adsorption Affinity

A metal−organic framework, PCN-9, containing entatic metal centers, has been synthesized and crystallographically characterized. The H2 and CH4 adsorption enthalpies of PCN-9 are among the highest reported thus far

Recent Development of Metal–Organic Frameworks for Water Purification

Water contamination is an increasing concern to mankind because of the increasing amount of pollutants in aquatic ecosystems. To purify the polluted water, various techniques have been used to remove hazardous components. Unfortunately, traditional cleanup techniques with a low uptake capacity are unable to achieve water purification. Metal–organic frameworks (MOFs) have recently shown potential in effective water pollutant isolation in terms of selectivity and adsorption capacity over traditional porous materials. The high surface area and versatile functionality of MOFs allow for the development of new adsorbents. The development of MOFs in a range of water treatments in the recent five years will be highlighted in this review, along with assessments of the adsorption performance relevant to the particular task. Moreover, the outlook on future opportunities for water purification using MOFs is also provided

Biomimetic Catalysis of a Porous Iron-Based Metal–Metalloporphyrin Framework

A porous metal–metalloporphyrin framework, MMPF-6, based upon an iron­(III)-metalated porphyrin ligand and a secondary binding unit of a zirconium oxide cluster was constructed; MMPF-6 demonstrated interesting peroxidase activity comparable to that of the heme protein myoglobin as well as exhibited solvent adaptability of retaining the peroxidase activity in an organic solvent

Tailored Porous Organic Polymers for Task-Specific Water Purification

ConspectusThe Industrial Revolution has resulted in social and economic improvements, but unfortunately, with the development of manufacturing and mining, water sources have been pervaded with contaminants, putting Earth’s freshwater supply in peril. Therefore, the segregation of pollutantssuch as radionuclides, heavy metals, and oil spillsfrom water streams, has become a pertinent problem. Attempts have been made to extract these pollutants through chemical precipitation, sorbents, and membranes. The limitations of the current remediation methods, including the generation of a considerable volume of chemical sludge as well as low uptake capacity and/or selectivity, actuate the need for materials innovation. These insufficiencies have provoked our interest in the exploration of porous organic polymers (POPs) for water treatment. This category of porous material has been at the forefront of materials research due to its modular nature, i.e., its tunable functionality and tailorable porosity. Compared to other materials, the practicality of POPs comes from their purely organic composition, which lends to their stability and ease of synthesis. The potential of using POPs as a design platform for solid extractors is closely associated with the ease with which their pore space can be functionalized with high densities of strong adsorption sites, resulting in a material that retains its robustness while providing specified interactions depending on the contaminant of choice.POPs raise opportunities to improve current or enable new technologies to achieve safer water. In this Account, we describe some of our efforts toward the exploitation of the unique properties of POPs for improving water purification by answering key questions and proposing research opportunities. The design strategies and principles involved for functionalizing POPs include the following: increasing the density and flexibility of the chelator to enhance their cooperation, introducing the secondary sphere modifiers to reinforce the primary binding, and enforcing the orientation of the ligands in the pore channel to increase the accessibility and cooperation of the functionalities. For each strategy, we first describe its chemical basis, followed by presenting examples that convey the underlying concepts, giving rise to functional materials that are beyond the traditional ones, as demonstrated by radionuclide sequestration, heavy metal decontamination, and oil-spill cleanup. Our endeavors to explore the applicability of POPs to deal with these high-priority contaminants are expected to impact personal consumer water purifiers, industrial wastewater management systems, and nuclear waste management. In our view, more exciting will be new applications and new examples of the functionalization strategies made by creatively merging the strategies mentioned above, enabling increasingly selective binding and efficiency and ultimately promoting POPs for practical applications to enhance water security

Reticular Synthesis of a Series of HKUST-like MOFs with Carbon Dioxide Capture and Separation

We reported a series of HKUST-like MOFs based on multiple copper-containing secondary building units (SBUs). Compound <b>1</b> is constructed by two SBUs: Cu₂­(CO₂)₄ paddle-wheel SBUs and Cu₂I₂ dimer SBUs. Compound <b>2</b> has Cu₂­(CO₂)₄ paddle-wheel SBUs and Cu₄I₄ SBUs. Furthermore, compound <b>3</b> possesses Cu₂­(CO₂)₄ paddle-wheel SBUs, Cu₂I₂ dimer SBUs, and Cu­(CO₂)₄ SBUs. These compounds are promising materials for CO₂ capture and separation, because they all display commendable adsorption of CO₂ and high selectivity for CO₂ over CH₄ and N₂. It is worthy to note that compound <b>1</b> exhibits the highest Brunauer–Emmett–Teller surface area (ca. 901 m² g^–1) among the MOF materials based on Cu_<i>x</i>I_<i>y</i> SBUs. In addition, compound <b>3</b> is the first case that three copper SBUs coexist in MOFs

Investigation of Gas Adsorption Performances and H₂ Affinities of Porous Metal-Organic Frameworks with Different Entatic Metal Centers

Three isomorphous porous metal-organic frameworks (MOFs; PCN-9 (Co/Fe/Mn)) with entatic metal centers have been constructed on the basis of the trigonal planar H3TATB ligand and a novel square-planar secondary building unit. N2 adsorption isotherms at 77 K confirmed the permanent porosities of the three porous MOFs. Variable-temperature adsorption measurements of H2 revealed that the H2 affinities of the three porous MOFs are related to the nature of entatic metal centers, which reversely affect their H2 uptake capacities

Microporous Lanthanide Metal-Organic Frameworks Containing Coordinatively Linked Interpenetration: Syntheses, Gas Adsorption Studies, Thermal Stability Analysis, and Photoluminescence Investigation

Under solvothermal conditions, the reactions of trigonal-planar ligand, TATB (4,4′,4′′-s-triazine-2,4,6-triyl-tribenzoate) with Dy(NO3)3, Er(NO3)3, Y(NO3)3, Yb(NO3)3, gave rise to four microporous lanthanide metal-organic frameworks (MOFs), designated as PCN-17 (Dy), PCN-17 (Er), PCN-17 (Y), and PCN-17 (Yb), respectively. The four porous MOFs are isostructural, with their crystal unit parameters shrinking in the order of PCN-17 (Dy), PCN-17 (Y), PCN-17 (Er), and PCN-17 (Yb), which also reflects the lanthanides' contraction trend. All of them adopt the novel square-planar Ln4(μ4-H2O) cluster as the secondary building unit and contain coordinatively linked doubly interpenetrated (8,3)-connected nets. In addition to exhibiting interesting photoluminescence phenomena, the coordinatively linked interpenetration restricts the pore sizes and affords them selective adsorption of H2 and O2 over N2 and CO, as well as renders them with high thermal stability of 500−550 °C as demonstrated from TGA profiles

Microporous Lanthanide Metal-Organic Frameworks Containing Coordinatively Linked Interpenetration: Syntheses, Gas Adsorption Studies, Thermal Stability Analysis, and Photoluminescence Investigation

Under solvothermal conditions, the reactions of trigonal-planar ligand, TATB (4,4′,4′′-s-triazine-2,4,6-triyl-tribenzoate) with Dy(NO3)3, Er(NO3)3, Y(NO3)3, Yb(NO3)3, gave rise to four microporous lanthanide metal-organic frameworks (MOFs), designated as PCN-17 (Dy), PCN-17 (Er), PCN-17 (Y), and PCN-17 (Yb), respectively. The four porous MOFs are isostructural, with their crystal unit parameters shrinking in the order of PCN-17 (Dy), PCN-17 (Y), PCN-17 (Er), and PCN-17 (Yb), which also reflects the lanthanides' contraction trend. All of them adopt the novel square-planar Ln4(μ4-H2O) cluster as the secondary building unit and contain coordinatively linked doubly interpenetrated (8,3)-connected nets. In addition to exhibiting interesting photoluminescence phenomena, the coordinatively linked interpenetration restricts the pore sizes and affords them selective adsorption of H2 and O2 over N2 and CO, as well as renders them with high thermal stability of 500−550 °C as demonstrated from TGA profiles

Investigation of Gas Adsorption Performances and H₂ Affinities of Porous Metal-Organic Frameworks with Different Entatic Metal Centers

Three isomorphous porous metal-organic frameworks (MOFs; PCN-9 (Co/Fe/Mn)) with entatic metal centers have been constructed on the basis of the trigonal planar H3TATB ligand and a novel square-planar secondary building unit. N2 adsorption isotherms at 77 K confirmed the permanent porosities of the three porous MOFs. Variable-temperature adsorption measurements of H2 revealed that the H2 affinities of the three porous MOFs are related to the nature of entatic metal centers, which reversely affect their H2 uptake capacities