نتایج جستجو برای: alkali metal cations

تعداد نتایج: 230847  

Journal: :Proceedings of the National Academy of Sciences of the United States of America 2002
Maria Angeles Herranz Barbara Colonna Luis Echegoyen

Our recent work with cyclic and acyclic polyether self-assembled monolayers (SAMs) on gold is presented. A series of dithia-crown-tetrathiafulvalene derivatives with one or two disulfide groups has been prepared, and their SAMs on gold have been characterized by electrochemistry and by reflection-absorption infrared spectroscopy. These SAMs are extremely stable on repeated electrochemical poten...

2009
Hanne Nuss Martin Jansen

The two new ozonide compounds K([12]crown-4)2O3 · 1.5 NH3 (1) and Rb([12]crown-4)2O3 · 1.5 NH3 (2) were synthesized from the binary alkali metal ozonides and [12]crown-4 in liquid ammonia. The airand temperature-sensitive red, needle-shaped compounds crystallize isostructurally in the non-centrosymmetric space group Fdd2 (no. 43) with 16 formula units per unit cell. The lattice parameters are a...

2012
Shinzi Kato Motohiro Oguri Masaru Ishida

Alkali metal salts of thiocarboxylic acid, especially anhydrous salts, are of the most important starting materials. However, only a limited amount of information on their preparation and spectral data has been available because of their strong hygroscopicity [1]. Recently, the convenient preparation methods of a series of anhydrous alkali metal dithiocarboxylates were developed [2]. This resul...

Journal: :ChemSystemsChem 2022

The use of “fuel” compounds to drive chemical systems out equilibrium is currently interest because the potential for temporally controlled, responsive behavior. We have recently shown that transiently formed crown ethers exhibit counterintuitive templation effects when generated in presence alkali metal cations: “matched” cations, such as K+ with an 18-crown-6 analogue, suppress formation macr...

Journal: :Dalton transactions 2010
Janis Derendorf Mathias Kessler Carsten Knapp Monika Rühle Christoph Schulz

The alkali metal salts (M = Li, Na, K, Rb, Cs) of the perchlorinated closo-dodecaborate [B(12)Cl(12)](2-) were prepared by reaction of [NEt(3)H](2)[B(12)Cl(12)] with the corresponding alkali metal hydroxide. Crystallization of M(2)[B(12)Cl(12)] from liquid sulfur dioxide gave the sulfur dioxide complexes [Li(2)(SO(2))(8)][B(12)Cl(12)], Na(2)[B(12)Cl(12)].4SO(2), K(2)[B(12)Cl(12)].8SO(2), Rb(2)[...

2004
Mark Salomon

Formation constants for complexion between alkali metal cations and the crown ether 18C6 in the solvent 2-cyanopyridine at 3OoC were determined from conductance measurements. The method allows for precise determination of these formation constants up to values of K around 10" mol-' dm3. The method also f. permits accurate evaluation of association equilibrium constants between the complex speci...

1998
C. J. Erickson M. V. Romalis A. R. Young W. Happer Joseph Henry

We present a comprehensive theory of nuclear spin polarization of He and Xe gases by spin-exchange collisions with optically pumped alkali-metal vapors. The most important physical processes considered are ~1! spin-conserving spin-exchange collisions between like or unlike alkali-metal atoms; ~2! spin-destroying collisions of the alkali-metal atoms with each other and with buffer-gas atoms; ~3!...

A proton NMR method for the determination of the solvation numbers of alkaline earth cations with dimethylsulfoxide (DMSO) in nitromethane as diluent is described. The method is based on the monitoring of the resonance frequency of DMSO protons as a function of DMSO to metal ion mole ratio while keeping the metal ion concentration constant. The average solvation number of cations at any...

2016
Magdalena Gebala Steve Bonilla Namita Bisaria Daniel Herschlag

Electrostatics are central to all aspects of nucleic acid behavior, including their folding, condensation, and binding to other molecules, and the energetics of these processes are profoundly influenced by the ion atmosphere that surrounds nucleic acids. Given the highly complex and dynamic nature of the ion atmosphere, understanding its properties and effects will require synergy between compu...

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