J. Appl. Cryst.の発刊に際して

: The unpolarized absorption and circular dichroism spectra of the fundamental vibrational transitions of the chiral molecule, 4-methyl-2-oxetanone, are calculated ab initio. Harmonic force fields are obtained using Density Functional Theory (DFT), MP2, and SCF methodologies and a 5S4P2D/3S2P (TZ2P) basis set. DFT calculations use the Local Spin Density Approximation (LSDA), BLYP, and Becke3LYP (B3LYP) density functionals. Mid-IR spectra predicted using LSDA, BLYP, and B3LYP force fields are of significantly different quality, the B3LYP force field yielding spectra in clearly superior, and overall excellent, agreement with experiment. The MP2 force field yields spectra in slightly worse agreement with experiment than the B3LYP force field. The SCF force field yields spectra in poor agreement with experiment.The basis set dependence of B3LYP force fields is also explored: the 6-31G* and TZ2P basis sets give very similar results while the 3-21G basis set yields spectra in substantially worse agreements with experiment. jg

Ab initio calculation of vibrational absorption and circular dichroism spectra using density functional force fields

Organic carbonyl compounds are potentially low-cost, sustainable, and high energy density electrode materials, but are plagued by unsatisfactory active-site utilization, low discharge potentials and low rate discharge–charge performance in battery applications. We herein disclose a function-oriented design of carbonyl compounds with multi-electron reactions as positive electrode materials for rechargeable lithium batteries, showing that molecular orbital profiles and energetics can be applied for the prediction of carbonyl utilization and modulation of redox potentials. By embedding pre-aromatic 1,2-dicarbonyl moieties in the extended conjugated systems, the desirable molecules integrate all known stabilizing factors and enable full four-Li uptake. Remarkably, two new carbonyl electrodes, pyrene-4,5,9,10-tetraone and 1,10-phenanthroline-5,6-dione, deliver a reversible capacity of 360 mA h g−1 and an average working potential of 2.74 V, respectively, providing insights in designing high-energy organic positive electrodes of lithium batteries for efficient energy storage and conversion.

Function-oriented design of conjugated carbonyl compound electrodes for high energy lithium batteries

Dr. H.-g. Wang, S. Yuan, D.-l. Ma, X.-l. Huang, F.-l. Meng, Prof. X.-b. Zhang State Key Laboratory of Rare Earth Resource Utilization Changchun Institute of Applied Chemistry Chinese Academy of Sciences Changchun , 130022 , P. R. China E-mail: xbzhang@ciac.ac.cn S. Yuan, D.-l. Ma, F.-l. Meng Key Laboratory of Automobile Materials Ministry of Education, and School of Materials Science and Engineering Jilin University Changchun , 130012 , P. R. China

Tailored Aromatic Carbonyl Derivative Polyimides for High‐Power and Long‐Cycle Sodium‐Organic Batteries

Cyclic voltammetry is an attractive method for teaching a number of concepts in electrochemistry. Students usually come to the study of this technique with some familiarity with potentiometric measurements using pairs of chemical electrodes. Such measurements might be described as “passive” electrochemical analyses because the voltage of the system simply responds to changes in the concentration of one or more analyte, e.g. H in the case of a pH probe. Electrolysis, cyclic voltammetry, amperometry and several other techniques might be described as “active” electrochemical methods because the experimenter drives an electrochemical reaction by incorporating the chemistry into a circuit and then controlling the reaction by circuit parameters such as voltage.

Cyclic Voltammetry 의 원리와 응용

Reduction potentials of para‐substituted nitrobenzenes—an infrared, nuclear magnetic resonance, and density functional theory study

Electrochemical and density functional theory modeled reduction of enolized 1,3-diketones

Electronic properties of Fe charge transfer complexes – A combined experimental and theoretical approach

Chemical and electrochemical oxidation and reduction of dithizone

Air oxidation of ortho-fluorodithizone resulted in the first X-ray resolved structure of a disulfide of dithizone, validating the last outstanding X-ray structure in the oxidation of dithizone, H(2)Dz, which proceeds via the disulfide, (HDz)(2), to the deprotonated dehydrodithizone tetrazolium salt, Dz. Density functional theory calculations established the energetically favored tautomers along the entire pathway; in gas phase and in polar as well as nonpolar solvent environments. DFT calculations using the classic pure OLYP and PW91, or the newer B3LYP hybrid functional, as well as MP2 calculations, yielded the lowest energy structures in agreement with corresponding experimental X-ray crystallographic results. Atomic charge distribution patterns confirmed the cyclization reaction pathway and crystal packing of Dz. Time dependent DFT for the first time gave satisfactory explanation for the solvatochromic properties of dithizone, pointing to different tautomers that give rise to the observed orange color in methanol and green in dichloromethane. Concentratochromism of H(2)Dz was observed in methanol. Computed orbitals and oscillators are in close agreement with UV-visible spectroscopic experimental results.

Karel G. von Eschwege

Papers

Reduction potentials of para‐substituted nitrobenzenes—an infrared, nuclear magnetic resonance, and density functional theory study

Electrochemical and density functional theory modeled reduction of enolized 1,3-diketones

Electronic properties of Fe charge transfer complexes – A combined experimental and theoretical approach

Chemical and electrochemical oxidation and reduction of dithizone

Dithizone and its oxidation products: a DFT, spectroscopic, and X-ray structural study.