Related Experiment Video
Updated: Jul 28, 2026

In Situ Monitoring of Diffusion of Guest Molecules in Porous Media Using Electron Paramagnetic Resonance Imaging
Published on: September 2, 2016
87Rb spin diffusion in ferroelectric RbH2PO4 studied by two dimensional exchange NMR
1Institute of Quantum Electronics, ETH-Honggerberg, Zurich, CH-8093, Switzerland.
Abstract:
We separate the contributions of spectral spin diffusion and chemical exchange in the 2D exchange NMR spectra of 87Rb in the pseudo-spin glass Rb1-x(ND4)xD2PO4 by studying the 87Rb spin diffusion in the isostructural compound RbH2PO4 at 85K, where the system is frozen in the ferroelectric phase state. The fact that the spin-diffusion time (TSD) of a particular point in the 2D spectrum depends essentially on its distance from the diagonal, allowed, even for the case of an unresolved 2D spectrum, to determine TSD as a function of the frequency separation Delta over two orders of magnitude. In accordance with existing theories, T-1SD(Delta) was found to be of Gaussian shape. However, we found huge discrepancies between the calculated and the experimentally determined second moments. This failure of the theory is not understood at present. Copyright 1999 Academic Press.
Related Concept Videos
¹H NMR: Interpreting Distorted and Overlapping Signals
As Δν decreases and the signals move closer, the doublets appear increasingly distorted. The intensities of the inner lines increase at the cost of those of the outer lines as the signals are slanted or...
Two-Dimensional (2D) NMR: Overview
The first step is the preparation period, during which nucleus A is excited with a radiofrequency pulse.
Atomic Nuclei: Nuclear Spin State Population Distribution
NMR Spectroscopy: Spin–Spin Coupling
Spin–Spin Coupling Constant: Overview
Qualitatively, any spin plus-half nucleus polarizes the spins of its electrons to the minus-half state. Consequently, the paired electron in the hydrogen–carbon bond must have a...
2D NMR: Overview of Homonuclear Correlation Techniques
COSY90 is the standard two-dimensional (2D) COSY experiment that...

