28 research outputs found
Secondary building units as the turning point in the development of the reticular chemistry of MOFs.
Solid State Complex Chemistry: Formation, Structure, and Properties of Homoleptic Tetracyanamidogermanates RbRE[Ge(CN2)(4)] (RE = La, Pr, Nd, Gd)
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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
Structure, polymorphism and luminescence of cyanate iodides MI(OCN) (M = Ba, Eu, and Sr)
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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: Sr<sub>3</sub>(O<sub>3</sub>C<sub>3</sub>N<sub>3</sub>)<sub>2</sub> (SCY) and Eu<sub>3</sub>(O<sub>3</sub>C<sub>3</sub>N<sub>3</sub>)<sub>2</sub> (ECY)
The
new cyanurates Sr<sub>3</sub>(O<sub>3</sub>C<sub>3</sub>N<sub>3</sub>)<sub>2</sub> (SCY) and Eu<sub>3</sub>(O<sub>3</sub>C<sub>3</sub>N<sub>3</sub>)<sub>2</sub> (ECY) were prepared via exothermic solid
state metathesis reactions from MCl<sub>2</sub> (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-BaB<sub>2</sub>O<sub>4</sub> (β-BBO)