Jove
Visualize
お問い合わせ
JoVE
x logofacebook logolinkedin logoyoutube logo
JoVEについて
概要リーダーシップブログJoVEヘルプセンター
著者向け
出版プロセス編集委員会範囲と方針査読よくある質問投稿
図書館員向け
推薦の声購読アクセスリソース図書館諮問委員会よくある質問
研究
JoVE JournalMethods CollectionsJoVE Encyclopedia of Experimentsアーカイブ
教育
JoVE CoreJoVE BusinessJoVE Science EducationJoVE Lab Manual教員リソースセンター教員サイト
利用規約
プライバシーポリシー
ポリシー

関連する概念動画

Spin–Spin Coupling Constant: Overview01:08

Spin–Spin Coupling Constant: Overview

1.0K
In bromoethane, the three methyl protons are coupled to the two methylene protons that are three bonds away. In accordance with the n+1 rule, the signal from the methyl protons is split into three peaks with 1:2:1 relative intensities. The methylene protons appear as a quartet, with the relative intensities of 1:3:3:1.
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...
1.0K
Spin–Spin Coupling: Two-Bond Coupling (Geminal Coupling)01:20

Spin–Spin Coupling: Two-Bond Coupling (Geminal Coupling)

1.1K
Two NMR-active nuclei bonded to a central atom can be involved in geminal or two-bond coupling. Geminal coupling is commonly seen between diastereotopic protons in chiral molecules and unsymmetrical alkenes, among others.
The central atom need not be NMR-active because its electrons are affected by the electron polarization of the spin-active atoms. However, spin information is transmitted less effectively than in one-bond coupling, and 2J values are usually weaker than 1J values. The energy of...
1.1K
Spin–Spin Coupling: One-Bond Coupling01:17

Spin–Spin Coupling: One-Bond Coupling

1.1K
Coupling interactions are strongest between NMR-active nuclei bonded to each other, where spin information can be transmitted directly through the pair of bonding electrons. While nuclei polarize their electrons to the opposite spins, the bonding electron pair has opposite spins. Configurations with antiparallel nuclear spins are expected to be lower in energy. When coupling makes antiparallel states more favorable, J is considered to have a positive value. The one-bond coupling constant, 1J,...
1.1K
Spin–Spin Coupling: Three-Bond Coupling (Vicinal Coupling)01:22

Spin–Spin Coupling: Three-Bond Coupling (Vicinal Coupling)

1.1K
Vicinal or three-bond coupling is commonly observed between protons attached to adjacent carbons. Here, nuclear spin information is primarily transferred via electron spin interactions between adjacent C‑H bond orbitals. This generally favors the antiparallel arrangement of spins, so 3J values are usually positive.
The extent of coupling depends on the C‑C bond length, the two H‑C‑C angles, any electron-withdrawing substituents, and the dihedral angle between the...
1.1K
Singularity Functions for Shear01:26

Singularity Functions for Shear

193
In structural analysis, singularity functions are crucial in simplifying the representation of shear forces in beams under discontinuous loading. These functions describe discontinuous  variations in shear force across a beam with varying loads by using a single mathematical expression, regardless of the complexity of the loading conditions. The singularity functions are derived from creating a free-body diagram of the beam and then making conceptual cuts at specific points to examine the...
193
Radicals: Electronic Structure and Geometry01:07

Radicals: Electronic Structure and Geometry

4.2K
This lesson delves into the geometry of a radical, which is influenced by the electronic structure of the molecule. The principle is similar to that of a lone pair, where the unpaired electron influences the geometry at the radical center.
Accordingly, the structure of a trivalent radical lies between the geometries of carbocations and carbanions. An sp2-hybridized carbocation is trigonal planar, while an sp3-hybridized carbanion is trigonal pyramidal. Here, the difference in geometry is...
4.2K

こちらも読む

関連記事

共著者、ジャーナル、引用グラフによってこの研究に関連する記事。

並び替え
Same author

Fusing LandTrendr BCI and machine learning for spoil dump mapping.

Scientific reports·2025
Same author

Surface hopping with nuclear quantum effects through path-integral coarse graining.

The Journal of chemical physics·2025
Same author

Omics Insights Into the Effects of Highbush Blueberry and Cranberry Crop Agroecosystems on Honey Bee Health and Physiology.

Proteomics·2025
Same author

Beyond genomics: a multiomics future for parasitology.

Trends in parasitology·2025
Same author

Reactive molecular beam epitaxial growth of RuO<sub>2</sub>superconducting thin films.

Journal of physics. Condensed matter : an Institute of Physics journal·2025
Same author

Large Band Splitting in g-Wave Altermagnet CrSb.

Physical review letters·2024
Same journal

Nuclear Gradients from Auxiliary-Field Quantum Monte Carlo and Their Applications in ML-Driven Geometry Optimization and Transition State Search.

Journal of chemical theory and computation·2026
Same journal

Correction to "Cluster-in-Molecule Local Correlation Method with an Accurate Distant Pair Correction for Large Systems".

Journal of chemical theory and computation·2026
Same journal

Machine-Learned Force Fields for Lattice Dynamics at Coupled-Cluster Level Accuracy.

Journal of chemical theory and computation·2026
Same journal

Systematic Molecularity-Dependent Entropy Errors in Continuum/RRHO Solution Thermochemistry: Origin and Correction.

Journal of chemical theory and computation·2026
Same journal

After 100 Years of Quantum Mechanics: Toward a Constructive Observation-Centered Perspective.

Journal of chemical theory and computation·2026
Same journal

Sample-Based Quantum Diagonalization Methods for Modeling the Photochemistry of Diazirine and Diazo Compounds.

Journal of chemical theory and computation·2026
関連記事をすべて見る

関連する実験動画

Updated: Sep 10, 2025

Spin Saturation Transfer Difference NMR SSTD NMR: A New Tool to Obtain Kinetic Parameters of Chemical Exchange Processes
11:44

Spin Saturation Transfer Difference NMR SSTD NMR: A New Tool to Obtain Kinetic Parameters of Chemical Exchange Processes

Published on: November 12, 2016

18.1K

シングレット・ディラディカルのスピン密度関数調節

Yi Shi1, Yuming Shi2, Adam Wasserman3,4

  • 1State Key Laboratory for Artificial Microstructure and Mesoscopic Physics, Frontier Science Center for Nano-optoelectronics and School of Physics, Peking University, Beijing 100871, People's Republic of China.

Journal of chemical theory and computation
|August 22, 2025
PubMed
まとめ
この要約は機械生成です。

新しいスピン密度関数正規化 (SR) のアプローチは,シングレット二極関数に対する破れた対称性密度関数理論 (DFT) の計算の誤りを修正する. この方法は,サイクロブタディエンの自動化のような複雑な反応のエネルギーバリアを正確に予測します.

さらに関連する動画

Practical Aspects of Sample Preparation and Setup of 1H R1&#961; Relaxation Dispersion Experiments of RNA
08:17

Practical Aspects of Sample Preparation and Setup of 1H R1ρ Relaxation Dispersion Experiments of RNA

Published on: July 9, 2021

4.8K
Site Directed Spin Labeling and EPR Spectroscopic Studies of Pentameric Ligand-Gated Ion Channels
11:19

Site Directed Spin Labeling and EPR Spectroscopic Studies of Pentameric Ligand-Gated Ion Channels

Published on: July 4, 2016

10.7K

関連する実験動画

Last Updated: Sep 10, 2025

Spin Saturation Transfer Difference NMR SSTD NMR: A New Tool to Obtain Kinetic Parameters of Chemical Exchange Processes
11:44

Spin Saturation Transfer Difference NMR SSTD NMR: A New Tool to Obtain Kinetic Parameters of Chemical Exchange Processes

Published on: November 12, 2016

18.1K
Practical Aspects of Sample Preparation and Setup of 1H R1&#961; Relaxation Dispersion Experiments of RNA
08:17

Practical Aspects of Sample Preparation and Setup of 1H R1ρ Relaxation Dispersion Experiments of RNA

Published on: July 9, 2021

4.8K
Site Directed Spin Labeling and EPR Spectroscopic Studies of Pentameric Ligand-Gated Ion Channels
11:19

Site Directed Spin Labeling and EPR Spectroscopic Studies of Pentameric Ligand-Gated Ion Channels

Published on: July 4, 2016

10.7K

科学分野:

  • 量子化学について
  • コンピュータ化学
  • 理論化学

背景:

  • 折れた対称性の密度関数理論 (DFT) は,シングレット二極関数における静的相関のために広く使用されている.
  • この方法は,人工的なスピン対称性破裂のために複雑な電子構造に失敗する可能性があります.
  • シングレット・ディラディカルは, (準) 変異した境界軌道から生じる.

研究 の 目的:

  • シンメトリが破れた DFT の人工的シンメトリ破損によるエラーを修正する方法を開発する.
  • 複雑な電子構造を持つシステムのエネルギー計算の精度を向上させる.

主な方法:

  • スピン密度関数正規化 (SR) の導入
  • パーティション密度関数理論 (PDFT) の枠組みにおけるSRの統合.
  • シングレットダイラジカル移行状態のシステムであるサイクロブタディエンの自動化に適用する.

主要な成果:

  • SR-PDFTアプローチは,人工的な対称性破損によって引き起こされるエラーを効果的に修正します.
  • 従来の破られた対称性のDFT計算は,サイクロブタディエンの自動化移行状態エネルギーを過小評価する.
  • SR-PDFTは,サイクロブタディエンの自動化反応のための化学的に正確なバリアの高さを生成します.

結論:

  • SR-PDFT方法は,シングレットディラジカルにおける静的相関を処理するための堅固な方法を提供します.
  • このアプローチは,複雑なシステムにおける従来の不対称DFTの限界を克服します.
  • 反応バリアの高さの正確な予測が達成され,その方法の有効性が実証される.