関連する実験動画

Updated: Jul 19, 2026

Magnetic Tweezers for the Measurement of Twist and Torque
11:41

Magnetic Tweezers for the Measurement of Twist and Torque

Published on: May 19, 2014

マグネティックに等価なスピンシステムにおける個々の移行の観測

Konstantin Pervushin1, Beat Vögeli

  • 1Laboratory of Physical Chemistry, Swiss Federal Institute of Technology, ETH Hönggerberg, CH-8093 Zürich, Switzerland. kopeko@phys.chem.ethz.ch

Journal of the American Chemical Society
|August 9, 2003
PubMed
まとめ

新しい核磁共振 (NMR) 実験により,分子内のメチルスピン系を直接観察することができます. これらの方法により,残留二極結合 (RDC) と相互相関放松の正確な測定が可能になり,構造分析が強化されます.

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¹H NMR: Interpreting Distorted and Overlapping Signals

Spin systems where the difference in chemical shifts of the coupled nuclei is greater than ten times J are called first-order spin systems. These nuclei are weakly coupled, and their chemical shifts and coupling constant can generally be estimated from the well-separated signals in the spectrum.
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Atomic Nuclei: Nuclear Spin State Overview

NMR-active nuclei have energy levels called 'spin states' that are associated with the orientations of their nuclear magnetic moments. In the absence of a magnetic field, the nuclear magnetic moments are randomly oriented, and the spin states are degenerate. When an external magnetic field is applied, the spin states have only 2 + 1 orientations available to them. A proton with = ½ has two available orientations. Similarly, for a quadrupolar nucleus with a nuclear spin value of one, the...
Atomic Nuclei: Magnetic Resonance01:05

Atomic Nuclei: Magnetic Resonance

The number of nuclear spins aligned in the lower energy state is slightly greater than those in the higher energy state. In the presence of an external magnetic field, as the spins precess at the Larmor frequency, the excess population results in a net magnetization oriented along the z axis. When a pulse or a short burst of radio waves at the Larmor frequency is applied along the x axis, the coupling of frequencies causes resonance and flips the nuclear spins of the excess population from the...
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Atomic Nuclei: Nuclear Relaxation Processes

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Spin–Spin Coupling Constant: Overview

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Double Resonance Techniques: Overview

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