A5066878335- Metal-Organic Frameworks: Synthesis and Applications
- Covalent Organic Framework Applications
- Machine Learning in Materials Science
- X-ray Diffraction in Crystallography
- Organoboron and organosilicon chemistry
- Chalcogenide Semiconductor Thin Films
- Luminescence and Fluorescent Materials
- Crystallization and Solubility Studies
- Crystallography and molecular interactions
- Magnetism in coordination complexes
- Quantum Dots Synthesis And Properties
- Carbon dioxide utilization in catalysis
- Semiconductor materials and interfaces
- Inorganic Fluorides and Related Compounds
- Advanced Photocatalysis Techniques
- Synthesis and characterization of novel inorganic/organometallic compounds
- ZnO doping and properties
- Organic Electronics and Photovoltaics
- Carbon Nanotubes in Composites
- Graphene research and applications
- Copper-based nanomaterials and applications
- Asymmetric Hydrogenation and Catalysis
- Porphyrin and Phthalocyanine Chemistry
- Block Copolymer Self-Assembly
- Advanced Condensed Matter Physics
Boston University
2017-2018
Cornell University
2014-2017
Constructor University
2010-2016
Ithaca College
2016
Two new chemically stable [acid and base] 2D crystalline covalent organic frameworks (COFs) (TpPa-1 TpPa-2) were synthesized using combined reversible irreversible reactions. Syntheses of these COFs done by the Schiff base reactions 1,3,5-triformylphloroglucinol (Tp) with p-phenylenediamine (Pa-1) 2,5-dimethyl-p-phenylenediamine (Pa-2), respectively, in 1:1 mesitylene/dioxane. The expected enol-imine (OH) form underwent proton tautomerism, only keto-enamine was observed. Because nature total...
Three thermally and chemically stable isoreticular covalent organic frameworks (COFs) were synthesized via room-temperature solvent-free mechanochemical grinding. These COFs successfully compared with their solvothermally counterparts in all aspects. mechanochemically have moderate crystallinity remarkable stability boiling water, acid (9 N HCl), base [TpBD (MC) 3 NaOH TpPa-2 9 NaOH]. Exfoliation of COF layers was simultaneously observed formation during synthesis. The structures thus...
A series of five thermally and chemically stable functionalized covalent organic frameworks (COFs), namely, TpPa-NO2, TpPa-F4, TpBD-(NO2)2, TpBD-Me2, TpBD-(OMe)2 were synthesized by employing the solvothermal aldehyde-amine Schiff base condensation reaction. In order to complete series, previously reported TpPa-1, TpPa-2, TpBD have also been synthesized, altogether, eight COFs fully characterized through powder X-ray diffraction (PXRD), Fourier transform IR (FT-IR) spectroscopy, (13)C...
A strong bond: strategy based on intramolecular hydrogen-binding interactions in 2D covalent organic frameworks (COFs) is shown to improve the crystallinity, porosity, and chemical stability of material. The concept validated by removing hydrogen-bonding interaction methoxy analog which showed a lower crystallinity.
Covalent-Organic Frameworks (COFs) are a new family of 2D and 3D highly porous crystalline materials built light elements, such as boron, oxygen carbon. For all COFs, an AA stacking arrangement has been reported on the basis experimental powder XRD patterns, with exception COF-1 (AB stacking). In this work, we show that COFs is different originally suggested: COF-1, COF-5, COF-6 COF-8 considerably more stable if their either serrated or inclined, layers shifted respect to each other by ~1.4...
A novel class of metal organic frameworks (MOFs) has been synthesized from Cu-acetate and dicarboxylic acids using liquid phase epitaxy. The SURMOF-2 isoreticular series exhibits P4 symmetry, for the longest linker a channel-size 3 × nm2 is obtained, one largest values reported any MOF so far. High quality, ab-initio electronic structure calculations confirm stability regular packing (Cu++)2- carboxylate paddle-wheel planes with symmetry reveal, that structures are in fact metastable, fairly...
The concept of reticular chemistry is investigated to explore the applicability formation Covalent Organic Frameworks (COFs) from their defined individual building blocks. Thus, we have designed, optimized and a set reported hypothetical 2D COFs using Density Functional Theory (DFT) related based tight-binding (DFTB) method. Linear, trigonal hexagonal blocks been selected for designing COF layers. High-symmetry AA AB stackings are considered, as well low-symmetry serrated inclined latter...
We demonstrate the realization of hierarchically organized MOF (metal-organic framework) multilayer systems with pronounced differences in size nanoscale pores. Unusually large values for lattice constant mismatch at MOF-MOF heterojunctions are made possible by a particular liquid-phase epitaxy process. The multiheteroepitaxy is demonstrated isoreticular SURMOF-2 series [ Liu et al. Sci. Rep. 2012 , 2 921 ] fabricating trilayer constants 1.12, 1.34, and 1.55 nm. Despite these (20%)...
Eine starke Bindung: Durch Bildung von intermolekularen Wasserstoffbrücken in kovalenten organischen Gerüsten (COFs) können die Kristallinität, Porosität und chemische Stabilität des Materials verbessert werden (siehe Bild). Das Konzept wird anhand der analogen Methoxyverbindung, keine enthält entsprechend weniger stabil kristallin ist, validiert. As a service to our authors and readers, this journal provides supporting information supplied by the authors. Such materials are peer reviewed...
Typically, a Lewis acid and base can react with each other form classical adduct. The neutralization reaction however be prevented by ligating the bulky substituents resulting complex is known as "frustrated pair" (FLP). Since reactivity remains in formed complex, FLPs display interesting chemical activities, promising applications catalysis. For example, were shown to function first metal-free catalyst for molecular hydrogen activation. This, recent of FLPs, have opened new thriving...
Density-functional based tight-binding is a powerful method to describe large molecules and materials. Metal-Organic Frameworks (MOFs), materials with interesting catalytic properties very surface areas have been developed become commercially available. Unit cells of MOFs typically include hundreds atoms, which make the application standard Density-Functional methods computationally expensive, sometimes even unfeasible. The aim this paper prepare validate Self-Consistent Charge Tight Binding...
Frustrated Lewis pairs have great potential as metal-free catalysts, for example, the activation of molecular hydrogen. However, rational design improved catalysts is hampered because catalytic reaction mechanisms still remain largely unclear. In this study, we present a density-functional-theory-based metadynamics study hydrogen by typical frustrated pair, tBu3P/B(C6F5)3. The computed free-energy landscape reveals different path compared with ones in literature. Importantly, found roles...
Frustrated Lewis pairs (FLPs) are known for their ability to capture CO2. Although many FLPs have been reported experimentally and several theoretical studies carried out address the reaction mechanism, individual roles of acid base in CO2 still unclear. In this study, we employed density functional theory (DFT) based metadynamics simulations investigate complete path by tBu3P/B(C6F5)3 pair understand base. Interestingly, find that plays a more important role than Specifically, is crucial...
We have determined the effect of shape on charge transport characteristics nanocrystals. Our study looked at explicit determination electronic properties faceted nanocrystals that essentially probe limit current computational reach, i.e., from 1.53 to 2.1 nm in diameter. These nanocrystals, which resemble PbSe systems, are either bare or covered short ligands. They also differ shape, octahedral vs cube-octahedral, and superlattice symmetry (fcc bcc). provided insights electron hole coupling...
Diamond-like porous aromatic frameworks (PAFs) form a new set of materials that contain only carbon and hydrogen atoms within their frameworks. These structures have very low mass densities, large surface area, high porosity. Density-functional-based calculations indicate crystalline PAFs mechanical stability properties similar to those covalent organic Their exceptional structural make interesting for storage. Our theoretical investigations show exceptionally uptake at room temperature,...
Abstract We have studied the magnetic properties of SURMOF‐2 series metal–organic frameworks (MOFs). Contrary to bulk MOF‐2 crystals, where Cu 2+ ions form paddlewheels and are antiferromagnetically coupled, in this case connected via carboxylate groups a zipper‐like fashion. This unusual coupling spin within resulting one‐dimensional chains is found stabilize low‐temperature, ferromagnetic (FM) phase. In contrast other ordered 1D systems, no strong fields needed induce ferromagnetism. The...
Binary nanocrystal superlattices present unique opportunities to create novel interconnected nanostructures by partial fusion of specific components the superlattice. Here, we demonstrate binary AB6 superlattice PbSe and Fe2O3 nanocrystals as a model system transform central hexamer into single fused particle. We detailed structural analysis combining high-resolution X-ray scattering electron microscopy. Molecular dynamics simulations show optimum separation in agreement with experiment...
A roadblock in utilizing III-V semiconductors for scaled-down electronic devices is their poor dopant activation. As a first step to unravel the behavior InGaAs, we studied tendency formation computationally using two approaches: ab initio and semiempirical methods. We number of structural possibilities, such as impact local sites global environments. will show that considered here, Si, has discrete preferences certain nature its surroundings. Substitutional defects are clearly preferred...
In0.53Ga0.47As, a III–V compound semiconductor with high electron mobility, is expected to bring better performance than silicon in next-generation n-type MOSFET devices. However, one major challenge its wide scale adoption the difficulty of obtaining enough dopant activation. For Si-doped InGaAs, best current experimental result, involving 10 min furnace annealing at temperatures above 700 °C, yields free concentration 1.4×1019 cm–3, value that still falls short requirement for practical...
Optimising the performance of P3HT:PCBM (polymer–fullerene, P3HT – poly(3-hexylthiophene), PCBM [6, 6]-phenyl-C61-butyric acid methyl ester) blends for solar cell applications is currently impeded by our lack understanding effect processing conditions on resulting morphology and hence its performance. The literature has generally overlooked studying link between tacticity, which, in turn, affects charge mobility. conformational change from trans to cis adjacent thiophene rings backbone...
The solar cell efficiency of chalcogenide nanocrystals (quantum dots) has been limited in the past by insulation between neighboring quantum dots caused intervening, often long-chain, aliphatic ligands.
Abstract Die magnetischen Eigenschaften Metall‐organischer Gerüste (MOFs) der SURMOF‐2‐Serie wurden untersucht. Anders als bei Volumen‐MOF‐2‐Kristallen, denen Cu 2+ ‐Ionen in einer Schaufelrad‐Anordnung vorliegen und antiferromagnetisch gekoppelt sind, zeigen die Carboxylatgruppen hier eine reißverschlussartige Anordnung. Eine theoretische Analyse ergibt, dass diese ungewöhnliche Kopplung Spin‐ innerhalb entstehenden, eindimensionalen Ketten niedriger Temperatur ferromagnetische Phase...