Synthesis of 7,9-di-O-methyl-11-oxosibiromycinone

Carey, Francis A.; Giuliano, Robert M.

doi:10.1021/jo00320a028

Cited by 38 publications

(20 citation statements)

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“…The π electron number contributes to its aromaticity, which can also be reflected by the resonance energy. The resonance energy values of benzene, naphthalene, and phenanthrene are 152, 255, and 381 kcal/mol, 24 respectively, which are consistent with the order of their π electron numbers. Similar to thiophenic sulfur compounds, 2-MNap shows a higher adsorption selectivity than Nap, which may be attributed to the electron donation from the methyl group bonded to the aromatic system of 2-MNap.…”

Section: Discussionsupporting

confidence: 66%

Effects of Aromatics, Diesel Additives, Nitrogen Compounds, and Moisture on Adsorptive Desulfurization of Diesel Fuel over Activated Carbon

Xiao

Song

et al. 2012

Ind. Eng. Chem. Res.

127

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The present research is concerned with the question of why activated carbons that show good adsorption uptake for model diesel sulfur compounds are not effective for real diesel fuels. In this work, the effects of aromatics, O-containing fuel additives, nitrogen compounds, and moisture present in real diesel fuel on adsorption desulfurization (ADS) over a commercial activated carbon (AC-WPH) were investigated. Polyaromatics such as phenanthrene show a significant inhibiting effect on ADS, even at a concentration of less than 1.0 wt %, while monoaromatics such as butylbenzene, even up to 10 wt %, have a negligible effect. The adsorption of different sulfur compounds over AC-WPH can be attributed mainly to the interaction of their conjugated π electrons with the carbon surface, where the electron-donating methyl groups further enhance the interaction. Trace amounts of O-containing diesel additives, nitrogen compounds, and moisture all have inhibiting effects on adsorptive desulfurization over AC-WPH, which can be attributed partly to hydrogen-bonding interaction between polar groups.

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Section: Discussionsupporting

confidence: 66%

Effects of Aromatics, Diesel Additives, Nitrogen Compounds, and Moisture on Adsorptive Desulfurization of Diesel Fuel over Activated Carbon

Xiao

Song

et al. 2012

Ind. Eng. Chem. Res.

127

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“…Carboxylate groups quickly revert to the parallel position as restraints are released. There is an appreciable energy barrier that prevents rotation of carboxylate groups attached to phenyl rings because the group extends the system’s π conjugation (see Figure S30 of the Supporting Information), which is significant even considering possible overestimates of the barrier height in the classical force field.…”

Section: Results and Discussionmentioning

confidence: 98%

Understanding the Nanoscale Structure of Inverted Hexagonal Phase Lyotropic Liquid Crystal Polymer Membranes

Coscia¹,

Yelk²,

Glaser³

et al. 2018

J. Phys. Chem. B

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Periodic, nanostructured porous polymer membranes made from the cross-linked inverted hexagonal phase of self-assembled lyotropic liquid crystals (LLCs) are a promising class of materials for selective separations. In this work, we investigate an experimentally characterized LLC polymer membrane using atomistic molecular modeling. In particular, we compare simulated X-ray diffraction (XRD) patterns with experimental XRD data to quantify and understand the differences between simulation and experiment. We find that the nanopores are likely composed of five columns of stacked LLC monomers which surround each hydrophilic core. Evidence suggests that these columns likely move independently of each other over longer time scales than accessible via atomistic simulation. We also find that wide-angle X-ray scattering structural features previously attributed to monomer tail tilt are likely instead due to ordered tail packing. Although this system has been reported as dry, we show that small amounts of water are necessary to reproduce all features from the experimental XRD pattern because of asymmetries introduced by hydrogen bonds between the monomer head groups and water molecules. Finally, we explore the composition and structure of the nanopores and reveal that there exists a composition gradient rather than an abrupt partition between the hydrophilic and hydrophobic regions. A caveat is that the time scales of the dynamics are extremely long for this system, resulting in simulated structures that appear too ordered, thus requiring careful examination of the metastable states observed in order to draw any conclusions. The clear picture of the nanoscopic structure of these membranes provided in this study will enable a better understanding of the mechanisms of small-molecule transport within these nanopores.

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“…21 Since HDI does not form a protective layer with an EC-based electrolyte under the same conditions, we tend to attribute this difference to the absence of methyl protection, 19b,22 which reduces the nucleophilicity of positive charge and lowers the reactivity with the isocyanate group. 23 The resistances of electrodes aer 4.6 V(vs. Li/Li + ) -3 h polarization are tested on a semiconductor parameter analyzer. Since the probe for the conductivity test is 50 nm, this measurement should reveal the variation of mono-particle's resistance.…”

mentioning

confidence: 99%

Hexamethylene diisocyanate as an electrolyte additive for high-energy density lithium ion batteries

et al. 2015

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Hexamethylene diisocyanate can chemically react with the onium ion produced by the oxidation of propylene carbonate and in situ generate a novel interfacial layer that is stable at high potential. With an appropriate thickness of this film, LiNi 1/3 Co 1/3 Mn 1/3 O 2 presents significantly improved rate and cycle performances when tested between 2.5 and 4.6 V (vs. Li/Li + ).Lithium ion batteries (LIBs) have been rapidly developed since their rst commercialization in the 1990s by Sony. 1 To date, this technology has dominated the market of commercial electronic devices and penetrated into the elds of transportation and smart grids. 2 In contrast to aqueous systems, 3 LIB electrolytes utilize liquid carbonates as solvents, which enable their operating window to be widened to 1.2-4.3 V(vs. Li/Li + ). 4 Although the anodic working potential was pushed to $0.02 V(vs. Li/Li + ) by building a solid electrolyte interphase (SEI) layer, 5 the progress to li cathode limitation almost remained static for most of the solid remnants started to decompose above 4.35 V(vs. Li/ Li + ). 4 On the other hand, positively widening the working window could provide the possibility to fully utilize the commercial cathodes such as LiCoO 2 and LiNi 1ÀxÀy Co x Mn y O 2 , and enable the evaluation of novel materials including xLi 2 -MnO 3 $(1 À x)LiMnO 2 and LiNi 0.5 Mn 1.5 O 4 . 6 Obviously, using high-potential electrolytes has become one of the most promising strategies to enhance the cell's energy density.The utilization of anti-oxidative solvents seems to be the most easily implemented solution. The solvents with strong electron-withdrawing groups, such as sulfone and nitrile, 7 could endure the oxidation at high potential. Although they exhibited good stability even up to 6 V(vs. Li/Li + ), the electrolytes based on these solvents are not applicable in current commercial systems due to their inability to construct an effective SEI layer on the graphite anode. 8 Currently, these solvents are utilized as cosolvents, by which the cut-off potential could be lied by 100-200 mV. This improvement could be attributed to the absorption of anti-oxidative solvents on the active sites of cathodes. 7b,9Passivating the cathode with an inert layer is an alternative strategy to improve its cyclic stability. Coating inorganic ceramics, such as metal oxides and phosphates, could alleviate the side reactions between the electrolyte solvents and cathodes to make LiCoO 2 work normally at 4.4 V(vs. Li/Li + ) in state-of-theart electrolytes. 10 Building an organic lm with lower HOMO levels is also a feasible strategy, such as the uorinated decomposed products of phosphides. The uorine-containing fragments and subsequently generated oligomers present a better stability at high potential, as shown by Choi and Xu et al. 11 Using a polymer layer is another effective way to ameliorate the cyclic stability. With the appropriate concentration, aromatic derivatives 12 could form a thin layer on the cathode, instead of dimensional growth that will lead to ele...

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Synthesis of 7,9-di-O-methyl-11-oxosibiromycinone

Cited by 38 publications

References 0 publications

Effects of Aromatics, Diesel Additives, Nitrogen Compounds, and Moisture on Adsorptive Desulfurization of Diesel Fuel over Activated Carbon

Effects of Aromatics, Diesel Additives, Nitrogen Compounds, and Moisture on Adsorptive Desulfurization of Diesel Fuel over Activated Carbon

Understanding the Nanoscale Structure of Inverted Hexagonal Phase Lyotropic Liquid Crystal Polymer Membranes

Hexamethylene diisocyanate as an electrolyte additive for high-energy density lithium ion batteries

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