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Joseph A. Gauthier Dr. Colin F. Dickens Dr. Stefan Ringe Prof. Karen Chan 《Chemphyschem》2019,20(22):3074-3080
Modelling the electrolyte at the electrochemical interface remains a major challenge in ab initio simulations of charge transfer processes at surfaces. Recently, the development of hybrid polarizable continuum models/ab initio models have allowed for the treatment of solvation and electrolyte charge in a computationally efficient way. However, challenges remain in its application. Recent literature has reported that large cell heights are required to reach convergence, which presents a serious computational cost. Furthermore, calculations of reaction energetics require costly iterations to tune the surface charge to the desired potential. In this work, we present a simple capacitor model of the interface that illuminates how to circumvent both of these challenges. We derive a correction to the energy for finite cell heights to obtain the large cell energies at no additional computational expense. We furthermore demonstrate that the reaction energetics determined at constant charge are easily mapped to those at constant potential, which eliminates the need to apply iterative schemes to tune the system to a constant potential. These developments together represent more than an order of magnitude reduction of the computational overhead required for the application of polarizable continuum models to surface electrochemistry. 相似文献
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Juliane R. Sempionatto Aida Martin Laura García‐Carmona Abbas Barfidokht Jonas F. Kurniawan Jose R. Moreto Guangda Tang Andrew Shin Xiaofeng Liu Alberto Escarpa Joseph Wang 《Electroanalysis》2019,31(2):239-245
A flexible skin‐mounted microfluidic potentiometric device for simultaneous electrochemical monitoring of sodium and potassium in sweat is presented. The wearable device allows efficient natural sweat pumping to the potentiometric detection chamber, containing solid‐contact ion‐selective Na+ and K+ electrodes, during exercise activity. The fabricated microchip electrolyte‐sensing device displays good analytical performance and addresses sweat mixing and carry‐over issues of early epidermal potentiometric sensors. Such soft skin‐worn microchip platform integrates potentiometric measurement, microfluidic technologies with flexible electronics for real‐time wireless data transmission to mobile devices. The new fully integrated microfluidic electrolyte‐detection device paves the way for practical fitness and health monitoring applications. 相似文献
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Structural Chemistry - Boronic acids, R–B(OH)2, play an important role in synthetic, biological, medicinal, and materials chemistry. Borinic acids, R–BH(OH), find relevance in similar... 相似文献
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Katherine M. Marczenko Joseph A. Zurakowski Karlee L. Bamford Joshua W. M. MacMillan Saurabh S. Chitnis 《Angewandte Chemie (Weinheim an der Bergstrasse, Germany)》2019,131(50):18264-18269
A rigid naphthalenediamine framework has been used to prepare antimony hydrides that feature LUMO shapes and energies similar to those found in secondary boranes. By exploiting this feature, we introduce the first examples of uncatalyzed hydrostibination reactions of robust C≡C, C=C, C=O, and N=N bonds as new elementary hydrometalation reactions analogous to hydroboration. These results endorse the notion of a diagonal relationship between the lightest p‐block element and the heaviest Group 15 elements and may lead to the conception of novel reaction chemistry. 相似文献
7.
Joseph T. Perryman Forrest P. Hyler Jessica C. Ortiz-Rodríguez Apurva Mehta Ambarish R. Kulkarni 《Journal of Coordination Chemistry》2019,72(8):1322-1335
AbstractThe electronic structures of S and Mo as well as the local coordination of Mo are investigated as a function of metal promotion Chevrel-phase (CP) sulfides. We observe the effect of metal promoter-induced electron donation into the stoichiometric range MxMo6S8 (M?=?Fe, Ni, Cu; x?=?0–2) through analysis of X-ray absorption near-edge structure regions. We further observe the effect of this promotion on the bonding environment of Mo6 metal centers through extended X-ray absorption fine structure analysis. We monitor expansion and contraction of Mo6 octahedra with and without metal promotion, as has been predicted by Hückel molecular orbital theory. We further observe a marked tunability in the electronic structure of sulfur upon charge transfer between promoting species and Mo6S8 units. Average Mo6 octahedron Mo–Mo bond contraction from 2.76 Å to as short as 2.69 Å was observed upon incorporation of metal promoters, while intercluster separation displays a pronounced increase for promoter-host lattices compared to un-promoted Mo6S8. To corroborate spectroscopically observed phenomena, we performed computational analyses of spin-polarized densities of state for the CP materials investigated herein, where a detectable increase in sulfur-based frontier orbital population is observed in accordance with experimentally validated orbital filling. 相似文献
8.
Joseph I. Mapley Daniel A. W. Ross C. John McAdam Keith C. Gordon 《Journal of Coordination Chemistry》2019,72(8):1378-1394
AbstractFour new heteroleptic copper(I) complexes bearing either 2-pyridyl-1,2,3-triazole (pytri) or the related triphenylamine (TPA) substituted (TPA-tripy) ligands and the ancillary ligands 6,6′-dimesityl-2,2′-bipyridine (diMesbpy) or bis[(2-diphenylphosphino)phenyl] ether (POP) were synthesized in good yields (75-95%). All the complexes were extensively characterized using nuclear magnetic resonance (NMR) spectroscopies and electrospray ionization mass spectrometry (ESIMS) and in the case of the two pytri compounds the solid state structures were determined via X-ray crystallography. The pytri complexes showed MLCT absorption bands which shift from 433?nm for the diMesbpy complex to 347?nm for POP. TPA-pytri complexes introduce an ILCT band resulting in improved visible absorption (376?nm, 26,400 M?1 cm?1 for [Cu(TPA-pytri)(diMesbpy)](PF6)). Emission from this ILCT state (470?nm, Φ?=?0.08) was red-shifted compared to the free ligand with negligible effects from ancillary ligands. Band assignments were confirmed with resonance Raman spectroscopy and TD-DFT calculations. 相似文献
9.
Joseph Aswathy Fal Jacek Żyła Gaweł Mathew Suresh 《Journal of Thermal Analysis and Calorimetry》2019,135(2):1373-1380
Journal of Thermal Analysis and Calorimetry - Understanding the behavior of ionic liquids (ILs) in ionic liquid-based nanofluids has great significance for its proper application. The phase changes... 相似文献
10.
Joseph D. Martin 《Annalen der Physik》2019,531(10)
Mildred Dresselhaus is known for her influential research on the physics of carbon. Her wide‐ranging influence as a physics teacher, although well‐known to her students, has been less thoroughly examined. Exploring how Dresselhaus grew into her role teaching solid state physics at MIT reveals much about how that subfield evolved. 相似文献