A5065112729- Crystallization and Solubility Studies
- X-ray Diffraction in Crystallography
- Crystallography and molecular interactions
- Metal-Organic Frameworks: Synthesis and Applications
- Solar-Powered Water Purification Methods
- Crystal structures of chemical compounds
- Covalent Organic Framework Applications
- Molecular spectroscopy and chirality
- Adsorption and Cooling Systems
- Enzyme Structure and Function
- Luminescence and Fluorescent Materials
- Chemical Thermodynamics and Molecular Structure
- Solar Thermal and Photovoltaic Systems
- Spacecraft and Cryogenic Technologies
- Advanced NMR Techniques and Applications
- Computational Fluid Dynamics and Aerodynamics
- Groundwater and Isotope Geochemistry
- Advanced Theoretical and Applied Studies in Material Sciences and Geometry
- Polymer crystallization and properties
- Advanced Physical and Chemical Molecular Interactions
- Aerodynamics and Acoustics in Jet Flows
- Water-Energy-Food Nexus Studies
- CO2 Reduction Techniques and Catalysts
- Fuel Cells and Related Materials
- Advanced Nanomaterials in Catalysis
Kavli Energy NanoScience Institute
2016-2019
University of California, Berkeley
2014-2019
Lawrence Berkeley National Laboratory
2016-2019
Zvezda (Russia)
2019
Novosibirsk State University
2013-2014
University of California System
2014
Institute of Solid State Chemistry and Mechanochemistry
2013
University of Liverpool
2013
Atmospheric water is a resource equivalent to ~10% of all fresh in lakes on Earth. However, an efficient process for capturing and delivering from air, especially at low humidity levels (down 20%), has not been developed. We report the design demonstration device based porous metal-organic framework {MOF-801, [Zr6O4(OH)4(fumarate)6]} that captures atmosphere ambient conditions by using low-grade heat natural sunlight flux less than 1 sun (1 kilowatt per square meter). This capable harvesting...
Covalent organic frameworks writ large framework (COF) materials have been difficult to characterize structurally and exploit because they tend form powders or amorphous materials. Ma et al. studied a variety of three-dimensional COFs based on imine linkages (see the Perspective by Navarro). They found that addition aniline inhibited nucleation allowed growth crystals enough for single-crystal x-ray diffraction studies. Evans describe two-step process in which nanoscale seeds boronate...
Abstract Water scarcity is a particularly severe challenge in arid and desert climates. While substantial amount of water present the form vapour atmosphere, harvesting this by state-of-the-art dewing technology can be extremely energy intensive impractical, when relative humidity (RH) low (i.e., below ~40% RH). In contrast, atmospheric generators that utilise sorbents enable capture at RH conditions driven abundant source solar-thermal with higher efficiency. Here, we demonstrate an...
Next-generation MOF device and material for water production from desert air.
The electronic character of porphyrin active sites for electrocatalytic reduction CO2 to CO in a two-dimensional covalent organic framework (COF) was tuned by modification the reticular structure. Efficient charge transport along COF backbone promotes connectivity between remote functional groups and enables modulation catalytic properties system. A series oriented thin films these COFs found reduce at low overpotential (550 mV) with high selectivity (faradaic efficiency 87%) current...
Sorbent-assisted water harvesting from air represents an attractive way to address scarcity in arid climates. Hitherto, sorbents developed for this technology have exclusively been designed perform one cycle (WHC) per day, but the productivities attained with approach cannot reasonably meet rising demand drinking water. This work shows that a microporous aluminum-based metal-organic framework, MOF-303, can adsorption-desorption within minutes under mild temperature swing, which opens...
The use of two primary alkylamine functionalities covalently tethered to the linkers IRMOF-74-III results in a material that can uptake CO2 at low pressures through chemisorption mechanism. In contrast other amine-functionalized solid adsorbents primarily as ammonium carbamates, we observe using state NMR major product for this is carbamic acid. equilibrium reaction products also shifts carbamate when water vapor present; new finding has impact on control chemistry capture MOF materials and...
A chiral metal-organic framework, MOF-520, was used to coordinatively bind and align molecules of varying size, complexity, functionality. The reduced motional degrees freedom obtained with this coordinative alignment method allowed the structures be determined by single-crystal x-ray diffraction techniques. chirality MOF backbone also served as a reference in structure solution for an unambiguous assignment absolute configuration bound molecules. Sixteen representing four common functional...
Developing synthetic methodology to crystallize extended covalent structures has been an important pursuit of reticular chemistry. Here, we report a homogeneous route for imine organic frameworks (COFs) where crystallites emerge from clear solutions without forming amorphous polyimine precipitates. The key feature this is the utilization tert-butyloxycarbonyl group protected amine building blocks, which are deprotected in situ and gradually nucleate crystalline framework. We demonstrate...
We have demonstrated that the microenvironment of a highly anionic supramolecular catalyst can mimic active sites enzymes and impart rate accelerations million-fold or more. However, these microenvironments be challenging to study, especially in context understanding which specific features are responsible for its high performance. report here development an experimental mechanistic probe consisting two isostructural catalysts. When examined parallel transformations, behavior catalysts...
Despite numerous studies on chemical and thermal stability of metal-organic frameworks (MOFs), mechanical remains largely undeveloped. To date, no strategy exists to control the deformation MOFs under ultrahigh pressure. Here, we show that mechanically unstable MOF-520 can be retrofitted by precise placement a rigid 4,4'-biphenyldicarboxylate (BPDC) linker as "girder" afford robust framework: MOF-520-BPDC. This retrofitting alters how structure deforms pressure thus leads drastic enhancement...
Coordinative alignment of target small molecules onto a chiral metal–organic framework (MOF-520)provides powerful method to determine the structures through single-crystal X-ray diffraction (SXRD). In this work, 17 with eight new coordinating functionalities and varying size have been determined by method, four which are complex being crystallized for first time. The chirality MOF backbone not only enables enantioselective crystallization from racemic mixture but also imposes...
Experiments and computations are reported of how stretching a polymer containing an ester moiety affects the kinetics its basic hydrolysis (see picture). DFT complete conformational ensembles three homologous esters suggest that force stabilizes tetrahedral intermediate second transition state (TS) but has no effect on relative energy first TS. As service to our authors readers, this journal provides supporting information supplied by authors. Such materials peer reviewed may be re-organized...
Crystal structures of amino acids are considered to mimic important interactions in peptides; therefore the studies structure-forming factors these systems attract much attention. N,N-Dimethylglycine is an interesting model compound that was used test role N–H···O hydrogen bonds forming head-to-tail chains, main structural unit crystals acids. It hypothesized previously [Kolesov, B. A.; Boldyreva, E. V. J. Raman Spectrosc. 2010, 41, 670−677] additional side play chains acid zwitterions...
Infinite head-to-tail chains of zwitterions present in the crystals all amino acids are known to be preserved even after structural phase transitions. In order understand role N—H...O hydrogen bonds linking these rearrangements, crystal structures N -methyl derivatives glycine ( -methylglycine, or sarcosine, with two donors for bonding; polymorphs , -dimethylglycine, DMG-I and DMG-II, one donor bond; -trimethylglycine, betaine, no bonds) were studied at different pressures. Methylation has...
Experimentell und rechnerisch wurde untersucht, wie sich das Dehnen eines Ester-haltigen Polymers auf die Kinetik der basischen Hydrolyse auswirkt (siehe Bild). DFT-Rechnungen vollständiger Konformationsensembles aus drei homologen Estern besagen, dass Zugkraft tetraedrische Zwischenstufe den zweiten Übergangszustand (TS) stabilisiert, jedoch keinen Einfluss relative Energie des ersten TS hat. As a service to our authors and readers, this journal provides supporting information supplied by...
The first example of oxidative stress H2O2 on the α-amino acid's amino group resulting in crystallization not only acid perhydrates but also a hydroxylamine derivative is illustrated by study double methylated N-derivative glycine. structures N-hydroxy-N,N-dimethylglycine and N,N-dimethylglycine as well anhydrous were analyzed X-ray crystallography.
The crystal structures of N-methyl derivatives the simplest amino acid glycine, namely sarcosine (C3H7NO2) and betaine (C5H11NO2), were studied upon cooling by single-crystal X-ray diffraction polarized Raman spectroscopy. effects decreasing temperature increasing hydrostatic pressure on compared. In particular, we have behavior those structural motifs in crystals, which are involved rearrangement during pressure-induced phase transitions. contrast to their high sensitivity compression,...
The title compound, betaine 0.77-perhydrate 0.23-hydrate, (CH 3 ) N + CH 2 COO − ·0.77H O ·0.23H O, crystallizes in the orthorhombic noncentrosymmetric space group Pca 1 . Chiral molecules of hydrogen peroxide are positionally disordered with water a ratio 0.77:0.23. Betaine, 2-(trimethylazaniumyl)acetate, preserves its zwitterionic state, positively charged ammonium and negatively carboxylate group. molecular conformation here differs from conformations both anhydrous hydrate, mainly...
It is well known that infinite head to tail chains built of zwitterions linked each other by N-H...O hydrogen bonds are common structural motifs in crystals amino acids. These coincide with directions the smallest compressibility a crystal structure on cooling and increasing pressure can even remain after phase transitions. However one should take into account dual nature these chains. From hand acids formed from head, group, tail, carboxylate group. besides bonding there electrostatic...