Mechanism of proton conductivity in polyvinyl alcohol-phenolsulfonic acid membranes from 1H and 13C NMR dataVolkovV.I.RebrovA.I.SanginovE.A.AnokhiningentaconnectRussian Journal of Electrochemistry C/c of ElektrokhimiiaV. I. Volkov, A. I. Rebrov, E. A. Sanginov, E. M. Anokhin, S. L....
The proton of the alkyl oxonium ion is deprotonated by a Lewis base, which is water in the dehydration of alcohols. The electron pair in the C—H bond “moves” to form a carbon–carbon double bond, and the electron pair of the C—O bond is retained by the oxygen atom. The reaction...
NMRHYDROXYL-PROTON CHEMICAL SHIFTSAQUEOUS SOLUTIONST -BUTYL ALCOHOLT -BUTYL AMINEMIXTURESHydroxyl-proton chemical shifts for water and it/i-butyl alcohol in water + it/i-butyl alcohol mixtures with ge; 8 mol% it/i-butyl alcohol, and the average hydroxyl and amino proton chemical shift for ...
In 1H MAS NMR, the change in chemical shift may be due to weak H-bonding interaction in Sn‒O‒H moieties. Higher the low-field movement of chemical shift, greater is the strength of acidic sites, caused by bond polarization in Sn‒O‒H groups. Importantly, the acidic strength in...
Hydrogen bonding can be monitored through the characteristic downfield shift of the resonance of proton participating. 20 The miscibility of the multicomponent polymers can be estimated through the examination of intermolecular NOE.21 Here we wish to present the results of high-resolution NMR study on...
The Cr2O72-ion (Cr VI) forms HCrO4–in acidic aqueous solution, which can eliminate a molecule of water to give the reagent CrO3. This then oxidises alcohols to a aldehydes and ketones via the chromate ester intermediate. The reduced chromium Cr (IV) can undergo series of reactions bri...
Proton MR spectra were acquired on a clinical 3 T GE human scanner equipped with a high-strength insert gradient coil (Adalsteinsson et al, 2004). Coronal fast spin-echo images (echo time (TE)1/TE2/repetition time (TR)=12.0/62.6/3000 ms, field of view=8 × 4 cm2, 256 × ...
(25 ppm) and offers high proton conductivity. Furthermore, humidity tests showed that by increasing the humidity, the resistance of the sensor decreases, which resulted in an increase in the response. The structure of the sensor was based on an alcohol fuel cell, which can be used in the ...
(Received September 21, 2000; Accepted November 13, 2000) ABSTRACT: Different hydrogen-bonded states ofOH groups in poly(vinyl alcohol) (PVA) films with different tactici- ties have been characterized by 1H combined rotation and multiple pulse spectroscopy (CRAMPS), solid-state 13C NMR and two...
13C NMR spectra were recorded using the DEPTQ sequence and internal deuterium lock. Chemical shifts are reported in ppm from tetramethyl silane (TMS) with the solvent resonance as the internal standard. Chemical shift values for 31P spectra are reported downfield of phosphoric acid. Proton ...