Proton magnetic resonance chemical shifts and the hydrogen bond in concentrated aqueous electrolyte solutions

1973 ◽  
Vol 77 (15) ◽  
pp. 1869-1876 ◽  
Author(s):  
E. J. Sare ◽  
C. T. Moynihan ◽  
C. A. Angell
Keyword(s):  
Hydrogen Bond ◽  
Magnetic Resonance ◽  
Proton Magnetic Resonance ◽  
Aqueous Electrolyte ◽  
Chemical Shifts ◽  
Electrolyte Solutions ◽  
Aqueous Electrolyte Solutions

The Investigation of Cation–Anion Interactions by 39K Nuclear Magnetic Resonance

1972 ◽  
Vol 50 (23) ◽  
pp. 3926-3930 ◽  
Author(s):  
E. G. Bloor ◽  
R. G. Kidd
Keyword(s):  
Nuclear Magnetic Resonance ◽  
Magnetic Resonance ◽  
Aqueous Electrolyte ◽  
Chemical Shifts ◽  
Electrolyte Solutions ◽  
Outer Electron ◽  
Aqueous Electrolyte Solutions ◽  
Nuclear Magnetic

The 39K chemical shifts in a number of aqueous electrolyte solutions have been determined. These arise from the overlapping of the outer electron orbitals of the anion and cation during random ionic collisions. The magnitudes of the chemical shifts are shown to be directly proportional to the effectiveness of this overlap interaction.

A Proton Magnetic Resonance Study of the Influence of Base Ionization on the Conformation of Pseudouridine

1972 ◽  
Vol 50 (7) ◽  
pp. 766-774 ◽  
Author(s):  
Roxanne Deslauriers ◽  
Ian C. P. Smith
Keyword(s):  
Hydrogen Bond ◽  
Magnetic Resonance ◽  
Proton Magnetic Resonance ◽  
Chemical Shifts ◽  
Deuterium Oxide ◽  
Coupling Constants ◽  
Hydroxyl Group ◽  
Basic Solution ◽  
Hydroxymethyl Group ◽  
Ultraviolet Spectra

The proton magnetic resonance spectra of alkaline deuterium oxide solutions of α-pseudouridine (α-ψ), β-pseudouridine (β-ψ), and 1-(β-D-ribofuranosyl)-cyanuric acid (β-CAR) are analyzed to explore the possibility that conformational changes are responsible for the unusual ultraviolet spectra of β-ψ at high pH. The largest change in ribose ring conformation due to increased alkalinity is observed in β-ψ; the ribose ring, although interconverting between various puckered forms, shows a slight preference for the 2′-endo and 3′-exo conformations. There is also a preference by α-ψ and β-ψ for the gauche-gauche rotamers about the exocyclic C4′–C5′ bond; this preference is not shown by β-CAR. No change occurs in the chemical shifts of the protons of α-ψ and β-ψ on going from neutral or acidic to basic solution. Increasing temperature to 60 °C causes no significant change in either coupling constants or chemical shifts. Comparison of chemical shifts observed in β-ψ with those found in β-CAR leads us to believe that the base remains in the anti conformation with respect to the ribose ring and is therefore incapable of forming a hydrogen bond with the exocyclic hydroxyl group as had been postulated previously to explain anomalous ultraviolet spectral data. A weak hydrogen bond between the 5′-hydroxymethyl group and the 5–6 double bond remains as a plausible explanation for the unusual ultraviolet spectra.

Promoting Nitrogen Electroreduction to Ammonia with Bismuth Nanocrystals and Potassium Cations in Water

2020 ◽  
Author(s):  
Jaecheol Choi ◽  
Hoang-Long Du ◽  
Manjunath Chatti ◽  
Bryan H. R. Suryanto ◽  
Alexandr Simonov ◽  
...  
Keyword(s):  
Electrocatalytic Activity ◽  
Aqueous Electrolyte ◽  
Electrolyte Solutions ◽  
Reduction Reaction ◽  
Nitrogen Reduction ◽  
Aqueous Electrolyte Solutions

We demonstrate that bismuth exhibits no measurable electrocatalytic activity for the nitrogen reduction reaction to ammonia in aqueous electrolyte solutions, contrary to several recent reports on the highly impressive rates of Bi-catalysed electrosynthesis of NH<sub>3</sub> from N<sub>2</sub>.

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