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Results for “fluorination”
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Bismuth Coordination Polymers with Fluorinated Linkers: Aqueous Stability, Bivolatility, and Adsorptive Behavior
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Oxygen Isotope and Fluorine Impurity Signatures during the Conversion of Uranium Ore Concentrates to Nuclear Fuel
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Neutron Diffraction Study of Significant sp 3 and sp 2 C–H Bond Shortening in a Fluorinated Pyridinium Saccharinate
Here we have experimentally shown by neutron diffraction significant shortening of both $sp^3$- and $sp^2$-hybridized C–H bonds to 1.092(2) and 1.081(1) Å in a hydrogen-bonded crystal of a difluorinated compound, 4-((2,2-difluoroethoxy)methyl)pyridinium saccharinate. Both MP2 and DFT calculations affirmed the C–H bond shrinkages. Sanderson’s electronegativity equalization principle provides insight into the shortening of the C–H covalent bond lengths for both $sp^3$- and $sp^2$-hybridized carbon atoms. To the best of our knowledge, this neutron diffraction study has revealed the largest extents of $sp^3$ and $sp^2$ C–H bond shrinkages with a 3-sigma rule being satisfied.
Uncovering the re-distribution mechanism of Ni in a de-alloyed Ni-Cr alloy in molten fluorinated salts
A mechanism of Ni redeposition during dealloying corrosion of Ni-Cr is investigated. A model Ni20Cr (wt%) metal alloy was exposed to molten LiF-NaF-KF eutectic (FLiNaK) at 600 °C and at an applied potential of +2.1 VK+/K, above the critical potential for onset of dealloying. Upon extended exposure times (up to 12 h), prominent salt-filled corrosion channels emerge along grain boundaries. A unique grain boundary corrosion mechanism, with respect to the exposed faces of the grains, a central focus of this investigation, is intrinsically connected to the formation of high purity Ni-rich de-alloyed regions within the salt-filled channel. We implement microscale techniques such as energy dispersive spectroscopy (EDS) and electron backscatter diffraction (EBSD) to uncover morphological and compositional variations in relevance to the formation of bicontinuous porosity from corrosion dealloying. To rationalize our findings, a phase-field model is developed and discovers a mechanism in which dissolved Ni from one grain can be redeposited on an adjacent grain at a given difference in interfacial energies. The interaction of chemical and structural factors at the grain boundaries plays a central role in elucidating the dynamics of this phenomenon and its implications towards corrosion.
Comment on “Non-PGM electrocatalysts for PEM fuel cells: effect of fluorination on the activity and stability of a highly active NC_Ar + NH 3 catalyst” by Gaixia Zhang, Xiaohua Yang, Marc Dubois, Michael Herraiz, Régis Chenitz, Michel Lefèvre, Mohamed Cherif, François Vidal, Vassili P. Glibin, Shuhui Sun and Jean-Pol Dodelet, Energy Environ. Sci. , 2019, 12 , 3015–3037, 10.1039/C9EE00867E
Proper kinetic and thermodynamic models are important in addressing durability as a major issue facing PGM-free ORR electrocatalysts.
Aliovalent fluorine doping and anodization-induced amorphization enable bifunctional catalysts for efficient water splitting
Abstract not provided
Synthesis of 2D anatase TiO 2 with highly reactive facets by fluorine-free topochemical conversion of 1T-TiS 2 nanosheets
Highly crystalline anatase TiO 2 nanosheets, made by controlled oxidation of TiS 2 nanosheets, expose the {001} and {100} facets, giving rise to enhancement in HER as compared to Degussa P25 TiO 2 nanoparticles. No enhancement in ORR was observed.
Synthesis of fluorinated aminium cations coupled with carborane anions for use as strong one-electron oxidants
Synthesis of a series of hydrocarbon-soluble triarylamines bearing F, CF 3 , and Br substituents showing quasi-reversible redox events in the 0.59–1.32 V range is reported. A few have been isolated as [HCB 11 Cl 11 ] − salts.
Lithium-ion battery functionality over broad operating conditions via local high concentration fluorinated ester electrolytes
Delivered capacities of non-flammable LHCE vs. flammable LiPF 6 EC:DMC electrolyte at low temperature, high voltage charge, and fast charge.
Photoluminescence switching in quantum dots connected with fluorinated and hydrogenated photochromic molecules
We investigate switching of photoluminescence from PbS quantum dots crosslinked with photochromic diarylethene molecules with different degree of halogenation.
Fluorine-18 incorporation and radiometal coordination in macropa ligands for PET imaging and targeted alpha therapy
The development of theranostic agents for radiopharmaceuticals based on therapeutic alpha emitters marks an important clinical need.
Versatile functionalization of de-fluorinated FMOF-1 towards enhanced carbon capture and separation: a predictive molecular simulation study
CF 3 alteration in FMOF-1 to different X groups yields enhanced porosity and selectivity for specific guests (e.g., CO 2 adsorption was improved for all X variants; for X = COOH, CO 2 /CH 4 = 59.6 & CO 2 /N 2 = 128.7, >40× vs . FMOF-1).
Effects of de-fluorination on hydrophobicity and on CO 2 and CH 4 adsorption under high humidity in MeMOFs, methylated analogues of FMOFs
Superhydrophobicity of MeMOFs, methylated analogues of FMOFs (CF 3 → CH 3 ) is predicted by GCMC simulations (high-RH CO 2 or CH 4 adsorption in MeMOFs > FMOFs) validated experimentally (H 2 O contact angle ∼172° for MeMOF@plastic dry-coated substrates).
Structural analysis of ionic liquids with symmetric and asymmetric fluorinated anions
Abstract not provided