Reductive Decomposition Mechanism of Prop-1-ene-1,3-sultone in the Formation of a Solid–Electrolyte Interphase on the Anode of a Lithium-Ion Battery

A novel electrolyte additive, prop-1-ene-1,3-sultone (PES), has recently attracted great attention due to its formation of effective solid–electrolyte interphase (SEI) films and remarkable cell performance in lithium-ion batteries. Herein, the reductive decomposition of PES is investigated through density functional calculations combined with a self-consistent reaction field method, in which the bulk solvent effect is accounted for by the geometry optimization and transition-state search. We examine three ring-opening pathways, namely, O–C, S–C, and S–O bond-breaking processes. Our calculations reveal that the Li⁺ ion plays a pivotal role in the reductive decomposition of PES. While the most kinetically favored processthe S–O bond breakingis effectively blocked via the formation of an intermediate structure, namely, the Li⁺-participated seven-membered ring, the other decomposition processes via O–C and S–C bond breaking lead to stable decomposition products. The constituents of SEI observed in previous experimental studies, such as RSO₃Li and ROSO₂Li, can be reasonably understood as the decomposition products resulting from O–C and S–C bond breaking, respectively

Ligand Field Effect at Oxide–Metal Interface on the Chemical Reactivity of Ultrathin Oxide Film Surface

Ultrathin oxide film is currently one of the paramount candidates for a heterogeneous catalyst because it provides an additional dimension, i.e., film thickness, to control chemical reactivity. Here, we demonstrate that the chemical reactivity of ultrathin MgO film grown on Ag(100) substrate for the dissociation of individual water molecules can be systematically controlled by interface dopants over the film thickness. Density functional theory calculations revealed that adhesion at the oxide–metal interface can be addressed by the ligand field effect and is linearly correlated with the chemical reactivity of the oxide film. In addition, our results indicate that the concentration of dopant at the interface can be controlled by tuning the <i>drawing effect</i> of oxide film. Our study provides not only profound insight into chemical reactivity control of ultrathin oxide film supported by a metal substrate but also an impetus for investigating ultrathin oxide films for a wider range of applications

Deboronation-Induced Turn-on Phosphorescent Sensing of Fluorides by Iridium(III) Cyclometalates with <i>o</i>‑Carborane

Heteroleptic tris-cyclometalated Ir­(III) complexes bearing an <i>o</i>-carborane at the 4- or 5-position in the phenyl ring of the ppy ligand (<i>closo</i>-<b>1</b> and -<b>2</b>) were prepared and characterized. The X-ray crystal structure of <i>closo</i>-<b>1</b> reveals the <i>fac</i> arrangement of the three C^∧N chelates around the Ir atom. Treatment of <i>closo</i> complexes with fluoride anions led to selective deboronation of the <i>closo</i>-carborane cage, producing the corresponding <i>nido</i>-carborane-substituted complexes (<i>nido</i>-<b>1</b> and <b>-2</b>). Whereas <i>closo</i>-<b>1</b> and -<b>2</b> were almost nonemissive in THF, <i>nido</i>-<b>1</b> and -<b>2</b> were highly phosphorescent (Φ_PL = 0.94–0.95). Theoretical studies suggested that, while the emission quenching in <i>closo</i>-<b>1</b> can be ascribed to the substantial involvement of <i>o</i>-carborane in the ³MLCT excited state, the intraligand charge transfer (³ILCT) state from the <i>nido</i>-carborane to pyridyl moieties is responsible for the efficient phosphorescence in <i>nido</i>-<b>1</b>. The addition of fluoride to the buffered THF/H₂O solution (1/1, v/v, pH 7) of <i>closo</i>-<b>1</b> and -<b>2</b> under mild heating led to strong emission intensity, allowing the turn-on phosphorescence detection of fluoride in aqueous medium at the ppb level

Direct Pathway to Molecular Photodissociation on Metal Surfaces Using Visible Light

We demonstrate molecular photodissociation on single-crystalline metal substrates, driven by visible-light irradiation. The visible-light-induced photodissociation on metal substrates has long been thought to never occur, either because visible-light energy is much smaller than the optical energy gap between the frontier electronic states of the molecule or because the molecular excited states have short lifetimes due to the strong hybridization between the adsorbate molecular orbitals (MOs) and metal substrate. The S–S bond in dimethyl disulfide adsorbed on both Cu(111) and Ag(111) surfaces was dissociated through direct electronic excitation from the HOMO-derived MO (the nonbonding lone-pair type orbitals on the S atoms (n_S)) to the LUMO-derived MO (the antibonding orbital localized on the S–S bond (σ*_SS)) by irradiation with visible light. A combination of scanning tunneling microscopy and density functional theory calculations revealed that visible-light-induced photodissociation becomes possible due to the interfacial electronic structures constructed by the hybridization between molecular orbitals and the metal substrate states. The molecule–metal hybridization decreases the gap between the HOMO- and LUMO-derived MOs into the visible-light energy region and forms LUMO-derived MOs that have less overlap with the metal substrate, which results in longer excited-state lifetimes

Bivariate Correlation Matrix of Annual Percentage Changes in Average BMD of L2-L4 with Various Parameters.

<p>A values in square means a correlation coefficient between various parameters. A red line in scatterplot is linear regression line in two parameters. Mean, average of values at baseline and follow-up; ΔPs, differences between baseline and follow-up parameters; BMI, body mass index; PBF, percent body fat; TSH, thyroid stimulating hormone; T3, triiodothyronine; T4, thyroxine; UA, uric acid; FBS, fasting blood sugar; HbA1c, hemoglobin A1c; ALT, alanine aminotransferase; TC, total cholesterol; TG, triglyceride; HDL-C, high density lipoprotein cholesterol; LDL-C, low density lipoprotein cholesterol; Cr, creatinine; eGFR, estimated glomerular filtration rate by Cockcroft-Gault calculator; CRP, C-reactive protein; L1 BMD, lumbar1 bone mineral density; n, number.</p

Bivariate Correlation Matrix of the Average BMD of L2-L4 with Various Parameters at Follow-up.

<p>A values in square means a correlation coefficient between various parameters. A red line in scatterplot is linear regression line in two parameters. BMI, body mass index; PBF, percent body fat; TSH, thyroid stimulating hormone; T3, triiodothyronine; T4, thyroxine; UA, uric acid; FBS, fasting blood sugar; HbA1c, hemoglobin A1c; ALT, alanine aminotransferase; TC, total cholesterol; TG, triglyceride; HDL-C, high density lipoprotein cholesterol; LDL-C, low density lipoprotein cholesterol; Cr, creatinine; eGFR, estimated glomerular filtration rate by Cockcroft-Gault calculator; CRP, C-reactive protein; L1 BMD, lumbar1 bone mineral density; n, number.</p

Estimated Marginal Means of Annual Percentage Loss in Average BMD of L2-L4 for Selected Risk Factors.

<p>Estimated marginal means in SPSS general linear model are adjusted for the covariates. Covariates appearing in the model are evaluated at the following values: age, percent body fat, TSH, free T4, uric acid, TG, eGFR, ΔBMI, and ΔALT. The subjects were split into three equally sized groups (tertiles) according to age (40~42, 43~46, 47~54, years), percent body fat (13.9~24.7, 24.8~29.5, 29.6~40.3, %), serum TSH levels (0.27~1.38, 1.39~2.19, 2.20~4.17, mIU/L), and uric acid (1.5~3.5, 3.6~4.2, 4.3~7.1, mg/dL) in the baseline check-up. a,b same or different letters denote no or significant differences between the groups. Significant differences between the groups are based on Bonferroni method. EMM, Estimated marginal means.</p

Elucidation of Isomerization Pathways of a Single Azobenzene Derivative Using an STM

The predominant pathway for the isomerization between <i>cis</i>- and <i>trans</i>-azobenzeneseither (i) inversion by the bending of an NNC bond or (ii) rotation by the torsion of two phenyl ringscontinues to be a controversial topic. To elucidate each isomerization pathway, a strategically designed and synthesized azobenzene derivative was investigated on a Ag(111) surface. This was achieved by exciting the molecule with tunneling electrons from the tip of a scanning tunneling microscope (STM). Structural analyses of the molecularly resolved STM images reveal that both inversion and rotation pathways are available for isomerization on a metal surface and strongly depend on the initial adsorption structures of the molecule. On the basis of the potential energy diagrams for the isomerization, it is concluded that isomerization pathways on a metal surface are not simply related to the excited states

Bivariate Correlation Matrix of the Average BMD of L2-L4 with Various Parameters at Baseline.

<p>A values in square means a correlation coefficient between various parameters. A red line in scatterplot is linear regression line in two parameters. BMI, body mass index; PBF, percent body fat; TSH, thyroid stimulating hormone; T3, triiodothyronine; T4, thyroxine; UA, uric acid; FBS, fasting blood sugar; HbA1c, hemoglobin A1c; ALT, alanine aminotransferase; TC, total cholesterol; TG, triglyceride; HDL-C, high density lipoprotein cholesterol; LDL-C, low density lipoprotein cholesterol; Cr, creatinine; eGFR, estimated glomerular filtration rate by Cockcroft-Gault calculator; CRP, C-reactive protein; L1 BMD, lumbar1 bone mineral density; n, number.</p

Atomic-Scale Dynamics of Surface-Catalyzed Hydrogenation/Dehydrogenation: NH on Pt(111)

Low-temperature scanning tunneling microscopy (LT-STM) was used to move hydrogen atoms and dissociate NH molecules on a Pt(111) surface covered with an ordered array of nitrogen atoms in a (2 × 2) structure. The N-covered Pt(111) surface was prepared by ammonia oxydehydrogenation, which was achieved by annealing an ammonia–oxygen overlayer to 400 K. Exposing the N-covered surface to H₂(g) forms H atoms and NH molecules. The NH molecules occupy face-centered cubic hollow sites, while the H atoms occupy atop sites. The STM tip was used to dissociate NH and to induce hopping of H atoms. Action spectra consisting of the reaction yield <i>versus</i> applied bias voltage were recorded for both processes, which revealed that they are vibrationally mediated. The threshold voltages for NH dissociation and H hopping were found to be 430 and 272 meV, corresponding to the excitation energy of the N–H stretching and the Pt–H stretching modes, respectively. Substituting H with D results in an isotopic shift of −110 and −84 meV for the threshold voltages for ND dissociation and D hopping, respectively. This further supports the conclusion that these processes are vibrationally mediated