Journal ArticleDOI
Reaction Rates by Nuclear Magnetic Resonance
Reads0
Chats0
TLDR
In this paper, the modified Bloch equations for nuclear magnetic resonance are modified to describe the magnetic resonance of a single nuclear species X which is transferred back and forth between two (or more) magnetic environments (A,B) by kinetic molecular processes.Abstract:
The Bloch equations for nuclear magnetic resonance are modified to describe the magnetic resonance of a single nuclear species X which is transferred back and forth between two (or more) magnetic environments (A,B) by kinetic molecular processes. The modified Bloch equations involve the usual assumptions of the Bloch theory and, in addition, require (a) that the X nuclear relaxation times be independent of the molecular exchange rates, and (b) that the X nuclear magnetization in A relax independently of the X magnetization in B, and vice versa. The modified Bloch equations are easily solved in the slow passage case, with arbitrary rf saturation. Earlier relations between reaction rates, and resonance line shapes, which were developed by Gutowsky, McCall, and Slichter, and extended by a number of other investigators, are easily derived using the modified Bloch equations. In the present work the modified equations are used to show how rapid exchange rates can sometimes be measured in solutions where the X r...read more
Citations
More filters
Journal ArticleDOI
NMR‐Relaxation Mechanisms of O17 in Aqueous Solutions of Paramagnetic Cations and the Lifetime of Water Molecules in the First Coordination Sphere
T. J. Swift,Robert E. Connick +1 more
TL;DR: In this paper, an investigation was made of the temperature and frequency dependence of T2 for O17 in aqueous solutions containing Mn2+, Fe2+, Co2+, Ni2+, and Cu2+.
Journal ArticleDOI
Proton Relaxation Times in Paramagnetic Solutions. Effects of Electron Spin Relaxation
N. Bloembergen,L. O. Morgan +1 more
TL;DR: In this article, it was shown that the distortion of the hydrated complex by collisions with other water molecules is responsible for the decrease in T2 in Mn++ (and other) solutions in very high magnetic fields.
Journal ArticleDOI
Study of Moderately Rapid Chemical Exchange Reactions by Means of Nuclear Magnetic Double Resonance
Sture Forsén,Ragnar A. Hoffman +1 more
TL;DR: In this paper, a nuclear magnetic double resonance method for the determination of chemical exchange rates has been developed, which is applicable to systems in which a nuclear spin is reversibly transferred between two nonequivalent sites, A and B, and is obtained through the study of the decay to a new equilibrium value of Signal A upon the sudden saturation of Signal B.
Journal ArticleDOI
Chemical exchange saturation transfer (CEST): what is in a name and what isn't?
TL;DR: The focus of this review is on basic magnetic resonance principles underlying CEST and similarities to and differences with conventional magnetization transfer contrast.
References
More filters
Journal ArticleDOI
Nuclear Magnetic Resonance Multiplets in Liquids
TL;DR: In this paper, the number and relative intensities of the components of a multiplet were determined by the number of and statistical weights of the various nuclear spin orientations of the nuclei causing the splitting.
Journal ArticleDOI
Dissociation, Chemical Exchange, and the Proton Magnetic Resonance in Some Aqueous Electrolytes
H. S. Gutowsky,A. Saika +1 more
TL;DR: In this paper, a theoretical analysis of the relation between the magnetic absorption line shape and the chemical exchange frequency suggests that rather short chemical lifetimes can be measured; at least one can infer from the appearance of a single or complex resonance that the average lifetime is greater or less than a determinable value in a range about 10−2 to 10−4 sec.
Journal ArticleDOI
Rates and Mechanisms of Protolysis of Methylammonium Ion in Aqueous Solution Studied by Proton Magnetic Resonance
TL;DR: In this paper, the application of the nuclear magnetic resonance technique to the study of fast protolysis reactions of methylammonium ion in water is described, and it is shown that reaction rates can be measured quantitatively for half-times in the range, 0.002 to 0.2 sec.
Journal ArticleDOI
Rates of Paramagnetic Pulse Reactions by Nuclear Magnetic Resonance
TL;DR: In this paper, the Bloch equations are used to establish a quantitative relation between nuclear resonance line shape, nuclear, and electron relaxation times, and the reaction rate, and discussed in terms of the Cu63 NMR work of McConnell and Weaver on electron exchange between Cu++ and Cu+ ions in hydrochloric acid solutions.