Related Experiment Video
Updated: Aug 5, 2026

Site Directed Spin Labeling and EPR Spectroscopic Studies of Pentameric Ligand-Gated Ion Channels
Published on: July 4, 2016
129Xe-Xe molecular spin relaxation
B Chann1, I A Nelson, L W Anderson
1Department of Physics, University of Wisconsin-Madison, Madison, Wisconsin 53706, USA.
Abstract:
We identify the formation of bound 129Xe-Xe molecules as the primary fundamental spin-relaxation process at densities below 14 amagat. Low pressure Xe relaxation rate measurements as a function of gas composition show that Xe-Xe molecular relaxation contributes 1/T1 = 1/4.1 h to the total observed relaxation rate. The measured rate is consistent with theoretical estimates deduced from previously measured NMR chemical shifts. At atmospheric pressure the molecular relaxation is more than an order of magnitude stronger than binary relaxation. Confusion of molecular and wall relaxation mechanisms has historically caused wall relaxation rates to be overestimated.
More Related Videos
Related Concept Videos
¹H NMR of Conformationally Flexible Molecules: Temporal Resolution
Atomic Nuclei: Nuclear Spin State Population Distribution
Atomic Nuclei: Nuclear Relaxation Processes
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...
Atomic Nuclei: Types of Nuclear Relaxation
In spin–lattice or longitudinal relaxation, the excited spins exchange energy with the surrounding lattice as they return to the lower energy level. Among several mechanisms that contribute to spin–lattice relaxation, magnetic dipolar interactions are significant. Here, the excited nucleus transfers energy to a nearby...
![Measuring the Spin-Lattice Relaxation Magnetic Field Dependence of Hyperpolarized [1-13C]pyruvate](/_next/image?url=https%3A%2F%2Fcloudfront.jove.com%2FCDNSource%2Fteasers%2F59399.jpg&w=3840&q=50)
