15NH/D-SOLEXSY experiment for accurate measurement of amide solvent exchange rates: application to denatured drkN SH3

2010 ◽  
Vol 46 (3) ◽  
pp. 227-244 ◽  
Author(s):  
Veniamin Chevelkov ◽  
Yi Xue ◽  
D. Krishna Rao ◽  
Julie D. Forman-Kay ◽  
Nikolai R. Skrynnikov
Keyword(s):  
Exchange Rates ◽  
Solvent Exchange ◽  
Amide Solvent ◽  
Amide Solvent Exchange

scholarly journals Modeling size controlled nanoparticle precipitation with the co-solvency method by spinodal decomposition

Soft Matter ◽  
2016 ◽  
Vol 12 (34) ◽  
pp. 7231-7240 ◽  
Author(s):  
Simon Keßler ◽  
Friederike Schmid ◽  
Klaus Drese
Keyword(s):  
Exchange Rates ◽  
Spinodal Decomposition ◽  
Scaling Relations ◽  
Solvent Exchange ◽  
Nanoparticle Sizes ◽  
Size Controlled

Experimentally observed scaling relations between nanoparticle sizes and solvent exchange rates can be explained by spinodal decomposition.

A Carbon-13 Nuclear Magnetic Resonance Study of Cation Solvation in Alcohols

1974 ◽  
Vol 52 (5) ◽  
pp. 744-748 ◽  
Author(s):  
Gerald W. Stockton ◽  
John S. Martin
Keyword(s):  
Nuclear Magnetic Resonance ◽  
Magnetic Resonance ◽  
Exchange Rates ◽  
Low Temperatures ◽  
Solvation Shell ◽  
Nuclear Magnetic Resonance Study ◽  
Solvent Exchange ◽  
Magnetic Resonance Study ◽  
Sign Reversal ◽  
Solvation Complex

Natural abundance 13C spectra of solvent coordinated to the cation have been observed in solutions of Mg(II) and Al(III) salts in alcohols. Carbon shielding changes induced by cations resemble those induced by electronegative substituents; a sign reversal between the β and γ positions is found in both instances. Solvent exchange rates correspond to those found by 1H n.m.r.; this confirms that whole molecule exchange is dominant. Selective relaxation of the solvation shell signals at low temperatures reflects differences in conformational mobility within the solvation complex.

Study of the exchange rates of ethanol and water on ferriprotoporphyrin IX by n.m.r. line broadening

1969 ◽  
Vol 47 (17) ◽  
pp. 3217-3224 ◽  
Author(s):  
N. S. Angerman ◽  
B. B. Hasinoff ◽  
H. B. Dunford ◽  
R. B. Jordan
Keyword(s):  
Exchange Rates ◽  
Temperature Jump ◽  
Aqueous Ethanol ◽  
Ion Pair ◽  
Solvent Composition ◽  
Water Proton ◽  
Solvent Exchange ◽  
Line Broadening ◽  
Kcal Mole ◽  
Ethanol Molecule

The nuclear magnetic resonance (n.m.r.) line broadening technique has been used to determine the rate of solvent exchange from the first coordination sphere of ferriprotoporphyrin IX (hemin) in aqueous ethanol. The line broadenings of the methyl and methylene protons of ethanol and the water protons have been studied as a function of solvent composition at 35° and of temperature in 48.8 mole % ethanol.The average values of the kinetic parameters for ethanol molecule exchange, taken from the CH3 and CH2 proton broadening are ΔH≠ = 6.2 ± 1.0 kcal mole−1 and ΔS≠ = −9.1 ± 4.4 cal mole−1 deg−1. Both proton transfer and water molecule exchange contribute to the water proton line broadening with a net value of ΔH≠ = 6.3 ± 0.5 kcal mole−1 and ΔS≠ = −3.8 ± 2.0 cal mole−1 deg−1.From the n.m.r. study at varying solvent composition, it is concluded that monomeric and dimeric hemin undergo solvent exchange at the same rate. The equilibrium constant for formation of the monoethanol solvated hemin from hydroxyhemin is determined as 8.7 at 35° from this study.A comparison of the rate of ethanol exchange (1.8 × 106 s−1 at 25°) and the rate of imidazole binding to hemin (from a separate temperature jump study) indicates that the imidazole substitution occurs through an SN1 ion pair mechanism.

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