نتایج جستجو برای: ionic bond
تعداد نتایج: 115031 فیلتر نتایج به سال:
Probing initial interactions at the interface of hybrid systems under humid conditions has the potential to reveal the local chemical environment at solid/solid interfaces under real-world, technologically relevant conditions. Here, we show that ambient pressure X-ray photoelectron spectroscopy (APXPS) with a conventional X-ray source can be used to study the effects of water exposure on the in...
Metal-thiolate active sites play major roles in bioinorganic chemistry. The M--S(thiolate) bonds can be very covalent, and involve different orbital interactions. Spectroscopic features of these active sites (intense, low-energy charge transfer transitions) reflect the high covalency of the M--S(thiolate) bonds. The energy of the metal-thiolate bond is fairly insensitive to its ionic/covalent a...
Li/CFx is one of the highest-energy-density primary batteries; however, poor rate capability hinders its practical applications in high-power devices. Here we report a preparation of fluorinated graphene (GFx) with superior performance through a direct gas fluorination method. We find that the so-called "semi-ionic" C-F bond content in all C-F bonds presents a more critical impact on rate perfo...
The title compound, C(13)H(16)N(3)O(+)·PF(6) (-), which has an imide group in the imidazolium cation, is a new ionic liquid above its melting point. Two neighbouring mol-ecules are connected by a weak non-classical C-H⋯O hydrogen bond with the formation of centrosymmetric 14-membered dimers.
A number of properties of interatomic surfaces, as defined by the quantum theory of atoms in molecules (QTAIM), are calculated for approximately 50 molecules. These integrated surface properties are then tested for their ability to correlate and predict bond energies from MP2 atomisation energies. Three surface properties, each with units of energy, are found to show strong correlations with bo...
The reliability of four force fields developed for 1-alkyl-3-methylimidazolium bis(trifluoromethylsulfonyl)imide ionic liquids are compared to an ab inito molecular dynamics simulation regarding structural properties. Except the hydrogen bond structure between the most acidic hydrogen atom of the imidazolium ring and the nitrogen atom of the anion as well as the intramolecular potential surface...
The electrochemistry of elemental sulfur (S(8)) and the polysulfides Na(2)S(4) and Na(2)S(6) has been studied for the first time in nonchloroaluminate ionic liquids. The cyclic voltammetry of S(8) in the ionic liquids is different to the behavior reported in some organic solvents, with two reductions and one oxidation peak observed. Supported by in situ UV-vis spectro-electrochemical experiment...
The heterocyclic ionic liquid-catalyzed direct oxidative amination of benzylic sp(3) C-H bonds via intermolecular sp(3) C-N bond formation for the synthesis of N-alkylated azoles under metal-free conditions is reported for the first time. The catalyst 1-butylpyridinium iodide can be recycled and reused with similar efficacies for at least eight cycles.
The fragmentation times corresponding to the loss of the chromophore (Cα-Cβ bond dissociation channel) after photoexcitation at 263 nm have been investigated for several small peptides containing tryptophan or tyrosine. For tryptophan-containing peptides, the aromatic chromophore is lost as an ionic fragment (m/z 130), and the fragmentation time increases with the mass of the neutral fragment. ...
The hydrogen bond donor-promoted fixation of CO(2) and epoxides into cyclic carbonates was investigated through experimental and density functional theory studies. A highly effective homogeneous system of 1,2-benzenediol-tetrabutyl ammonium bromide (TBAB) and heterogeneous poly-ionic liquids were developed for the fixation of CO(2) into cyclic carbonates via hydrogen bond activation, based on t...
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