BDPA-Nitroxide Biradicalsは,効率的なダイナミックな核極化強化の固体NMRで最大21.1Tの磁場に対応しています
Dorothea Wisser1, Ganesan Karthikeyan2, Alicia Lund1
1Institut de Sciences Analytiques, Centre de RMN à Très Hauts Champs , Université de Lyon (CNRS/ENS Lyon/UCB Lyon 1) , 69100 Villeurbanne , France.
Journal of the American Chemical Society
|September 26, 2018
まとめ
新しいハイブリッドバイラジカルは,ダイナミックな核極化 (DNP) 固体核磁気共鳴 (NMR) の感度を大幅に高めます. これらの新型極化剤は,様々な磁場と回転周波数で性能を改善し,詳細な材料分析を可能にします.
科学分野:
- 固体核磁共振 (NMR) スペクトロスコーピー
- ダイナミックな核極化 (DNP)
- 材料科学
背景:
- ダイナミックな核極化 (DNP) 固体NMRは,材料の調査に不可欠です.
- 既存の極化剤は,しばしば最適でないフィールドとマジック・アングル・スピニング (MAS) の周波数依存を示している.
- DNP-NMRの感度向上は,難しいサンプルを分析する上で非常に重要です.
研究 の 目的:
- 新しいハイブリッドバイラジカルを開発し,DNPの固体 NMR 感度を向上させる.
- DNPの極化剤の構造-特性関係を確立する.
- 無機物質の分析におけるこれらの剤の適用を実証する.
主な方法:
- BDPAとニトロキシードラジカルを組み合わせた新型のハイブリッドビラジカルの合成
- 性能を最適化するために電子間距離と酸化窒素置換剤を調整する.
- 高磁場 (18.8Tと21.1T) とMAS周波数 (40kHz) でのDNP強化因子の評価
主要な成果:
- 一連の溶解性のハイブリッドバイラジカルが合成され,特徴づけられた.
- 18. 8Tと40 kHzのMASで最大185のDNP増強を達成した.
- 60以上の増幅因子は,3.2ミリメートルのロータを用いて18.8Tと21.1Tで観察された.
結論:
- 開発されたハイブリッドビラジカルは,既存の薬と比較して優れたDNP性能を提供します.
- これらの新しい分極剤は,より高い感度で高フィールドDNP-NMR研究を可能にします.
- 形のないアルミシリケートとシリカナノ粒子の分析における成功例は,それらの実用的な有用性を示しています.
関連する概念動画
Nuclear Magnetic Resonance (NMR): Overview
6.9K
Nuclear magnetic resonance (NMR) is a phenomenon exhibited by certain nuclei that can absorb characteristic radio frequency radiation under certain conditions. NMR has been extensively applied in molecular spectroscopy and medical diagnostic imaging. In both these applications, the molecule or subject under study is placed in a magnetic field and irradiated with radio frequency energy.
NMR spectroscopy generates a spectrum where the characteristic absorption frequencies of the sample are...
NMR spectroscopy generates a spectrum where the characteristic absorption frequencies of the sample are...
6.9K
¹³C NMR: Distortionless Enhancement by Polarization Transfer (DEPT)
1.7K
When proton-coupled carbon-13 spectra are simplified by a broadband proton decoupling technique, structural information about the coupled protons is lost. Distortionless enhancement by polarization transfer (DEPT) is a technique that provides information on the number of hydrogens attached to each carbon in a molecule. While the DEPT experiment utilizes complex pulse sequences, the pulse delay and flip angle are specifically manipulated. The resulting signals have different phases depending on...
1.7K
Magnetic Fields
7.4K
A moving charge or a current creates a magnetic field in the surrounding space, in addition to its electric field. The magnetic field exerts a force on any other moving charge or current that is present in the field. Like an electric field, the magnetic field is also a vector field. At any position, the direction of the magnetic field is defined as the direction in which the north pole of a compass needle points.
A magnetic field is defined by the force that a charged particle experiences...
A magnetic field is defined by the force that a charged particle experiences...
7.4K
Nuclear Overhauser Enhancement (NOE)
1.5K
Irradiation of a spin-active nucleus causes an increase or decrease in the signal intensity of neighboring nuclei that are not necessarily chemically bonded or involved in J-coupling. This phenomenon, called the nuclear Overhauser enhancement (NOE), results from through-space interactions between the nuclear spins. The NOE effect decreases with increasing internuclear distance and is generally not observed beyond 4 angstroms. In NOE, dipole-dipole interactions between neighboring spin-active...
1.5K
Nuclear Fusion
33.9K
The process of converting very light nuclei into heavier nuclei is also accompanied by the conversion of mass into large amounts of energy, a process called fusion. The principal source of energy in the sun is a net fusion reaction in which four hydrogen nuclei fuse and ultimately produce one helium nucleus and two positrons.
A helium nucleus has a mass that is 0.7% less than that of four hydrogen nuclei; this lost mass is converted into energy during the fusion. This reaction produces about...
A helium nucleus has a mass that is 0.7% less than that of four hydrogen nuclei; this lost mass is converted into energy during the fusion. This reaction produces about...
33.9K
Magnetic Field of a Solenoid
5.9K
A solenoid is a conducting wire coated with an insulating material, wound tightly in the form of a helical coil. The magnetic field due to a solenoid is the vector sum of the magnetic fields due to its individual turns. Therefore, for an ideal solenoid, the magnetic field within the solenoid is directly proportional to the number of turns per unit length and the current. Conversely, the magnetic field outside the solenoid is zero.
Consider a solenoid with 100 turns wrapped around a cylinder of...
Consider a solenoid with 100 turns wrapped around a cylinder of...
5.9K


