Mediaspace scheduled maintenance: Aug 25, 2026 07:00 - 12:00 AM. During this time, videos will be temporarily unavailable. Check status updates.

Lecture

Spin Relaxation: Examples and Mechanisms

Description

This lecture covers the basic steps in magnetic resonance, focusing on spin relaxation mechanisms and their applications. Examples include protein structure determination, structural information from NOES, and spin-lattice relaxation times of different carbon types. The instructor discusses anisotropic rotation, alkyl chains, and solid benzene, highlighting the importance of dipolar coupling in spin relaxation and the nuclear Overhauser effect.

Official source

Ontological neighbourhood

Chemistry

Physical chemistry: Spectroscopy

Related concepts (20)

Nuclear magnetic resonance

Nuclear magnetic resonance (NMR) is a physical phenomenon in which nuclei in a strong constant magnetic field are perturbed by a weak oscillating magnetic field (in the near field) and respond by producing an electromagnetic signal with a frequency characteristic of the magnetic field at the nucleus. This process occurs near resonance, when the oscillation frequency matches the intrinsic frequency of the nuclei, which depends on the strength of the static magnetic field, the chemical environment, and the magnetic properties of the isotope involved; in practical applications with static magnetic fields up to ca.

Nuclear magnetic resonance spectroscopy

Nuclear magnetic resonance spectroscopy, most commonly known as NMR spectroscopy or magnetic resonance spectroscopy (MRS), is a spectroscopic technique to observe local magnetic fields around atomic nuclei. This spectroscopy is based on the measurement of absorption of electromagnetic radiations in the radio frequency region from roughly 4 to 900 MHz. Absorption of radio waves in the presence of magnetic field is accompanied by a special type of nuclear transition, and for this reason, such type of spectroscopy is known as Nuclear Magnetic Resonance Spectroscopy.

Nuclear Overhauser effect

The nuclear Overhauser effect (NOE) is the transfer of nuclear spin polarization from one population of spin-active nuclei (e.g. 1H, 13C, 15N etc.) to another via cross-relaxation. A phenomenological definition of the NOE in nuclear magnetic resonance spectroscopy (NMR) is the change in the integrated intensity (positive or negative) of one NMR resonance that occurs when another is saturated by irradiation with an RF field. The change in resonance intensity of a nucleus is a consequence of the nucleus being close in space to those directly affected by the RF perturbation.

Spin–spin relaxation

In physics, the spin–spin relaxation is the mechanism by which Mxy, the transverse component of the magnetization vector, exponentially decays towards its equilibrium value in nuclear magnetic resonance (NMR) and magnetic resonance imaging (MRI). It is characterized by the spin–spin relaxation time, known as T2, a time constant characterizing the signal decay. It is named in contrast to T1, the spin–lattice relaxation time.

Two-dimensional nuclear magnetic resonance spectroscopy

Two-dimensional nuclear magnetic resonance spectroscopy (2D NMR) is a set of nuclear magnetic resonance spectroscopy (NMR) methods which give data plotted in a space defined by two frequency axes rather than one. Types of 2D NMR include correlation spectroscopy (COSY), J-spectroscopy, exchange spectroscopy (EXSY), and nuclear Overhauser effect spectroscopy (NOESY). Two-dimensional NMR spectra provide more information about a molecule than one-dimensional NMR spectra and are especially useful in determining the structure of a molecule, particularly for molecules that are too complicated to work with using one-dimensional NMR.

Related lectures (40)

Relaxation & Structure

Explores relaxation and structure determination in NMR spectroscopy, covering nuclear spin relaxation, anisotropic interactions, NOESY experiments, and protein structure determination protocol.

Nuclear Magnetic Resonance: Principles and Applications

Explores the principles and applications of Nuclear Magnetic Resonance, covering chemical structure elucidation, peak interpretation, and medical imaging.

Spin echoes & coherence transfer

Explores spin echoes, coherence transfer, product operator formalism, and the INEPT experiment in NMR spectroscopy.

NMR Experiments: Basics and Applications

Explores the basic steps in magnetic resonance, including INEPT pulse sequences and two-dimensional NMR experiments like COSY and NOESY.

Spin Relaxation in Magnetic Resonance