Dynamical mechanism for the intermolecular relaxation of the excited NH stretching vibration of a pyrrole molecule in liquid solution

Marcus-Hush theory of electron transfer is one of the pillars of modern electrochemistry with a large body of supporting experimental evidence presented to date. However, some predictions, such as the electrochemical behavior at microdisk electrodes, remain unverified. Herein, we present a study of electron tunneling across a hexagonal boron nitride barrier between a graphite electrode and redox levels in a liquid solution. This was achieved by the fabrication of microdisk electrodes with a typical diameter of 5 µm. Analysis of voltammetric measurements, using two common redox mediators, yielded several electrochemical parameters, including the electron transfer rate constant, limiting current, and transfer coefficient. They show a significant departure from the Butler-Volmer behavior in a clear manifestation of the Marcus-Hush theory of electron transfer. In addition, our system provides a novel experimental platform, which could be applied to address a number of scientific problems such as identification of reaction mechanisms, surface modification, or long-range electron transfer.

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The Dynamical Mechanism for SMEs Evolution Under the Hologram Approach

SSRN Electronic Journal ◽

10.2139/ssrn.3325013 ◽

2019 ◽

Cited By ~ 2

Author(s):

George X Yuan ◽

Huiqin Wang ◽

Tu Zeng ◽

Tong Wu ◽

Silong Gao ◽

...

Keyword(s):

Dynamical Mechanism

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Infrared spectra and substituent effects in 2-(3-, and 4-substituted phenylmethylene)-1,3-cycloheptanediones

Collection of Czechoslovak Chemical Communications ◽

10.1135/cccc19830586 ◽

1983 ◽

Vol 48 (2) ◽

pp. 586-595 ◽

Cited By ~ 3

Author(s):

Alexander Perjéssy ◽

Pavol Hrnčiar ◽

Ján Šraga

Keyword(s):

Substituent Effects ◽

Phenyl Group ◽

Wave Number ◽

Vibrational Coupling ◽

Wave Numbers ◽

Stretching Vibration ◽

Stretching Vibrations ◽

The Relationship ◽

Derivatives Of ◽

Effect Of Structure

The wave numbers of the fundamental C=O and C=C stretching vibrations, as well as that of the first overtone of C=O stretching vibration of 2-(3-, and 4-substituted phenylmethylene)-1,3-cycloheptanediones and 1,3-cycloheptanedione were measured in tetrachloromethane and chloroform. The spectral data were correlated with σ+ constants of substituents attached to phenyl group and with wave number shifts of the C=O stretching vibration of substituted acetophenones. The slope of the linear dependence ν vs ν+ of the C=C stretching vibration of the ethylenic group was found to be more than two times higher than that of the analogous correlation of the C=O stretching vibration. Positive values of anharmonicity for asymmetric C=O stretching vibration can be considered as an evidence of the vibrational coupling in a cyclic 1,3-dicarbonyl system similarly, as with derivatives of 1,3-indanedione. The relationship between the wave numbers of the symmetric and asymmetric C=O stretching vibrations indicates that the effect of structure upon both vibrations is symmetric. The vibrational coupling in 1,3-cycloheptanediones and the application of Seth-Paul-Van-Duyse equation is discussed in relation to analogous results obtained for other cyclic 1,3-dicarbonyl compounds.

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Formation rate of LB-1-like systems through dynamical interactions

Publications of the Astronomical Society of Japan ◽

10.1093/pasj/psaa021 ◽

2020 ◽

Vol 72 (3) ◽

Cited By ~ 3

Author(s):

Ataru Tanikawa ◽

Tomoya Kinugawa ◽

Jun Kumamoto ◽

Michiko S Fujii

Keyword(s):

Open Cluster ◽

Formation Rate ◽

Open Clusters ◽

Type Star ◽

Dynamical Mechanism ◽

Milky Way Galaxy ◽

Triple Systems ◽

Stellar Collisions ◽

Solar Metallicity ◽

Helium Star

Abstract We estimate formation rates of LB-1-like systems through dynamical interactions in the framework of the theory of stellar evolution before the discovery of the LB-1 system. The LB-1 system contains a ∼70 ${M_{\odot}}$ black hole (BH), a so-called pair instability (PI) gap BH, and a B-type star with solar metallicity, and has nearly zero eccentricity. The most efficient formation mechanism is as follows. In an open cluster, a naked helium star (with ∼20 ${M_{\odot}}$) collides with a heavy main sequence star (with ∼50 ${M_{\odot}}$) which has a B-type companion. The collision results in a binary consisting of the collision product and the B-type star with a high eccentricity. The binary can be circularized through the dynamical tide with radiative damping of the collision product envelope. Finally, the collision product collapses to a PI-gap BH, avoiding pulsational pair instability and pair instability supernovae because its He core is as massive as the pre-colliding naked He star. We find that the number of LB-1-like systems in the Milky Way galaxy is ∼0.01(ρoc/104 ${M_{\odot}}$ pc−3), where ρoc is the initial mass densities of open clusters. If we take into account LB-1-like systems with O-type companion stars, the number increases to ∼0.03(ρoc/104 ${M_{\odot}}$ pc−3). This mechanism can form LB-1-like systems at least ten times more efficiently than the other mechanisms: captures of B-type stars by PI-gap BHs, stellar collisions between other types of stars, and stellar mergers in hierarchical triple systems. We conclude that no dynamical mechanism can explain the presence of the LB-1 system.

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ChemInform Abstract: INFRARED CIRCULAR DICHROISM ASSOCIATED WITH THE HYDROXYL-STRETCHING VIBRATION IN THE METHYL ESTER OF MANDELIC ACID

Chemischer Informationsdienst ◽

10.1002/chin.197848056 ◽

1978 ◽

Vol 9 (48) ◽

Author(s):

C. MARCOTT ◽

C. C. BLACKBURN ◽

T. R. FAULKNER ◽

A. MOSCOWITZ ◽

J. OVEREND

Keyword(s):

Circular Dichroism ◽

Methyl Ester ◽

Mandelic Acid ◽

Stretching Vibration ◽

Circular Dichroïsm

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Irregular Electrodeposition of Cu-Sn Alloy Coatings in [EMIM]Cl Outside the Glove Box with Large Layer Thickness

Coatings ◽

10.3390/coatings11030310 ◽

2021 ◽

Vol 11 (3) ◽

pp. 310

Author(s):

Lars Lehmann ◽

Dominik Höhlich ◽

Thomas Mehner ◽

Thomas Lampke

Keyword(s):

Layer Thickness ◽

Alloy System ◽

Liquid Solution ◽

Complexing Agents ◽

X Ray Diffraction ◽

X Ray ◽

Argon Stream ◽

Ionic Liquid Solution ◽

The Relationship ◽

Layer Composition

Thick Cu−Sn alloy layers were produced in an [EMIM]Cl ionic-liquid solution from CuCl2 and SnCl2 in different ratios. All work, including the electrodeposition, took place outside the glovebox with a continuous argon stream over the electrolyte at 95 °C. The layer composition and layer thickness can be adjusted by the variation of the metal-salts content in the electrolyte. A layer with a thickness of up to 15 µm and a copper content of up to ωCu = 0.86 was obtained. The phase composition was characterized by scanning electron microscopy (SEM), X-ray diffraction (XRD), and X-ray fluorescence (XRF). Furthermore, it was found that the relationship between the alloy composition and the concentration of the ions in the electrolyte is described as an irregular alloy system as according to Brenner. Brenner described such systems only for aqueous electrolytes containing complexing agents such as cyanide. In this work, it was confirmed that irregular alloy depositions also occur in [EMIM]Cl.

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Darstellung, 11B-, 13C-, 29Si-NMR- und Schwingungsspektren von Trimethylsilylmethyl-hexahydro-closo-hexaborat, [B6H6(CH2Si(CH3)3)]- sowie Kristallstruktur von [P(C6H5)4][B6H6(CH2Si(CH3)3)] / Preparation, 11B, 13C, 29Si NMR and Vibrational Spectra of Trimethylsilylmethyl-hexahydro-clo-hexaborate, [B6H6(CH2Si(CH 3)3)]-and the Crystal Structure of [P(C6H5)4] [B6H6(CH2Si(CH3)3)]

Zeitschrift für Naturforschung B ◽

10.1515/znb-1995-0706 ◽

1995 ◽

Vol 50 (7) ◽

pp. 1025-1029 ◽

Cited By ~ 1

Author(s):

J. Baurmeister ◽

A. Franken ◽

W. Preetz

Keyword(s):

Crystal Structure ◽

Monoclinic Space Group ◽

29Si Nmr ◽

X Ray Diffraction ◽

Nmr Spectrum ◽

X Ray ◽

Quadrupole Coupling ◽

Stretching Vibration ◽

Ir And Raman ◽

C Nmr

By reaction of [N(C4H9 )4]2 [B6H6] with iodomethyl-trimethylsilane in acetonitrile a solution with trimethylsilylm ethyl-closo-hexaborate(1-)anions, [B6H6 (CH2Si(CH3)3)]-, is formed. The crystal structure of [P(C6H5 )4][B6H6(CH2Si(CH3)3)] has been determined by single crystal X-ray diffraction analysis; monoclinic, space group P21/n with a = 16.140(2), b = 11.646(8), c = 16.731(3) Å, β 109.664(11)°. The 11B NMR spectrum reveals features of a mono hetero substituted octahedral B6 cage. The 13C NMR spectrum exhibits a quartet at +0.18 ppm with 1J(C,H) = 118 Hz for the three methyl groups and a weak multiplet at -0.65 ppm for the methylene bridge due to quadrupole coupling with the boron atoms. In the 29Si NMR spectrum a decet at +2.25 ppm with 2J(C,H ) = 6.9 Hz is observed. The B -C stretching vibration is observed at 1155 cm-1 in the IR and Raman spectrum.

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