Secondary building units as the turning point in the development of the reticular chemistry of MOFs.

The secondary building unit (SBU) approach was a turning point in the discovery of permanently porous metal-organic frameworks (MOFs) and in launching the field of reticular chemistry. In contrast to the single-metal nodes known in coordination networks, the polynuclear nature of SBUs allows these structures to serve as rigid, directional, and stable building units in the design of robust crystalline materials with predetermined structures and properties. This concept has also enabled the development of MOFs with ultra-high porosity and structural complexity. The architectural, mechanical, and chemical stability of MOFs imparted by their SBUs also gives rise to unique framework chemistry. All of this chemistry -including ligand, linker, metal exchange, and metallation reactions, as well as precisely controlled formation of ordered vacancies- is carried out with full retention of the MOF structure, crystallinity, and porosity. The unique chemical nature of SBUs makes MOFs useful in many applications including gas and vapor adsorption, separation processes, and SBU-mediated catalysis. In essence, the SBU approach realizes a long-standing dream of scientists by bringing molecular chemistry (both organic and inorganic) to extended solid-state structures. This contribution highlights the importance of the SBUs in the development of MOFs and points to the tremendous potential still to be harnessed

Covalent Organic Frameworks-Organic Chemistry Beyond the Molecule.

The synthesis of organic molecules has at its core, purity, definitiveness of structure, and the ability to access specific atoms through chemical reactions. When considering extended organic structures, covalent organic frameworks (COFs) stand out as a true extension of molecular organic chemistry to the solid state, because these three fundamental attributes of molecular organic chemistry are preserved. The fact that COFs are porous provides confined space within which molecules can be further modified and controlled

Conceptual Advances from Werner Complexes to Metal-Organic Frameworks.

Alfred Werner's work on the geometric aspects of how ligands bind to metal ions at the end of the 19th century has given rise, in the molecular realm, to organometallic, bioinorganic, and cluster chemistries. By stitching together organic and inorganic units into crystalline porous metal-organic frameworks (MOFs), the connectivity, spatial arrangement, and geometry of those molecular complexes can now be fixed in space and become directly addressable. The fact that MOFs are porous provides additional space within which molecules can further be transformed and their chemistry controlled. An aspect not available in molecular chemistry but a direct consequence of Werner's analysis of coordination complexes is the ability to have multivariable functionality in MOFs to bring about a continuum of chemical environments, within the repeating order of the framework, from which a substrate can sample and be transformed in ways not possible in molecular complex chemistry

Conceptual Advances from Werner Complexes to Metal-Organic Frameworks.

Alfred Werner's work on the geometric aspects of how ligands bind to metal ions at the end of the 19th century has given rise, in the molecular realm, to organometallic, bioinorganic, and cluster chemistries. By stitching together organic and inorganic units into crystalline porous metal-organic frameworks (MOFs), the connectivity, spatial arrangement, and geometry of those molecular complexes can now be fixed in space and become directly addressable. The fact that MOFs are porous provides additional space within which molecules can further be transformed and their chemistry controlled. An aspect not available in molecular chemistry but a direct consequence of Werner's analysis of coordination complexes is the ability to have multivariable functionality in MOFs to bring about a continuum of chemical environments, within the repeating order of the framework, from which a substrate can sample and be transformed in ways not possible in molecular complex chemistry

Synthesis and SHG Properties of Two New Cyanurates: Sr₃(O₃C₃N₃)₂ (SCY) and Eu₃(O₃C₃N₃)₂ (ECY)

The new cyanurates Sr₃(O₃C₃N₃)₂ (SCY) and Eu₃(O₃C₃N₃)₂ (ECY) were prepared via exothermic solid state metathesis reactions from MCl₂ (M = Sr, Eu) and K­(OCN) in silica tubes at 525 °C. Both structures were characterized by means of powder and single crystal X-ray diffraction, and their structures are shown to crystallize with the noncentrosymmetric space group <i>R</i>3<i>c</i> (No. 161). Infrared spectra and nonlinear optical properties (NLO) of SCY and ECY are reported in comparison to those of CCY and β-BaB₂O₄ (β-BBO)

Practical water production from desert air.

Energy-efficient production of water from desert air has not been developed. A proof-of-concept device for harvesting water at low relative humidity was reported; however, it used external cooling and was not desert-tested. We report a laboratory-to-desert experiment where a prototype using up to 1.2 kg of metal-organic framework (MOF)-801 was tested in the laboratory and later in the desert of Arizona, USA. It produced 100 g of water per kilogram of MOF-801 per day-and-night cycle, using only natural cooling and ambient sunlight as a source of energy. We also report an aluminum-based MOF-303, which delivers more than twice the amount of water. The desert experiment uncovered key parameters pertaining to the energy, material, and air requirements for efficient production of water from desert air, even at a subzero dew point

Synthesis and SHG Properties of Two New Cyanurates: Sr₃(O₃C₃N₃)₂ (SCY) and Eu₃(O₃C₃N₃)₂ (ECY)

The new cyanurates Sr₃(O₃C₃N₃)₂ (SCY) and Eu₃(O₃C₃N₃)₂ (ECY) were prepared via exothermic solid state metathesis reactions from MCl₂ (M = Sr, Eu) and K­(OCN) in silica tubes at 525 °C. Both structures were characterized by means of powder and single crystal X-ray diffraction, and their structures are shown to crystallize with the noncentrosymmetric space group <i>R</i>3<i>c</i> (No. 161). Infrared spectra and nonlinear optical properties (NLO) of SCY and ECY are reported in comparison to those of CCY and β-BaB₂O₄ (β-BBO)

The chemistry of CO2 capture in an amine-functionalized metal-organic framework under dry and humid conditions

The use of two primary alkylamine functionalities covalently tethered to the linkers of IRMOF-74-III results in a material that can uptake CO2 at low pressures through a chemisorption mechanism. In contrast to other primary amine-functionalized solid adsorbents that uptake CO2 primarily as ammonium carbamates, we observe using solid state NMR that the major chemisorption product for this material is carbamic acid. The equilibrium of reaction products also shifts to ammonium carbamate when water vapor is present; a new finding that has impact on control of the chemistry of CO2 capture in MOF materials and one that highlights the importance of geometric constraints and the mediating role of water within the pores of MOFs.Fil: Flaig, Robinson W.. University of California at Berkeley; Estados UnidosFil: Osborn Popp, Thomas M.. University of California at Berkeley; Estados UnidosFil: Fracaroli, Alejandro Matías. University of California at Berkeley; Estados Unidos. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto de Investigaciones en Físico-química de Córdoba. Universidad Nacional de Córdoba. Facultad de Ciencias Químicas. Instituto de Investigaciones en Físico-química de Córdoba; ArgentinaFil: Kapustin, Eugene A.. University of California at Berkeley; Estados UnidosFil: Kalmutzki, Markus J.. University of California at Berkeley; Estados UnidosFil: Altamimi, Rashid M.. King Abdulaziz City for Science and Technology; Arabia SauditaFil: Fathieh, Farhad. University of California at Berkeley; Estados UnidosFil: Reimer, Jeffrey A.. University of California at Berkeley; Estados Unidos. Lawrence Berkeley National Laboratory; Estados UnidosFil: Yaghi, Omar M.. University of California at Berkeley; Estados Unidos. King Abdulaziz City for Science and Technology; Arabia Saudit