Research of high-resolutions NMR measurements for solid 14N spins by Dynamic Sample spinning NMR

通过动态样品旋转 NMR 对固体 14N 自旋进行高分辨率 NMR 测量的研究

• 批准号: 15550007
• 负责人: KUWAHARA Daisuke
• 金额: $ 2.24万
• 依托单位: The UniversityofElectro-Communications
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for Scientific Research (C)
• 财政年份: 2003
• 资助国家: 日本
• 起止时间: 2003 至 2005
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/en/grant/KAKENHI-PROJECT-15550007/
• 关键词: 14N spin; overtone NMR

We tried to increase the spinning frequency of a rotor in a Dynamic Angle Spinning (DAS) NMR probe in 2003. To that end, we made some NMR rotors with different caps, and drove the DAS system using the rotors. The maximum rotor spinning frequency was, however, about 6kHz; we could not make the DAS system that can switch the spinning axis at the spinning frequency of more than 10kHz. We consequently adopted a different strategy in order to attain the objective of this study.First, we theoretically studied the indirect detection of overtone NMR for ^<23>Na nuclei in polycrystalline solids. As a result, we obtained the following findings:when the ^<23>Na overtone irradiation is performed using different irradiation frequencies, if we plot the central transition intensities against the irradiation frequencies, we can obtain a high-resolution NMR spectrum for ^<23>Na nuclei in solids.14N nuclei in polycrystalline solids also have two normal transitions and one overtone transition. Thus the above indirect detection method is applicable to the 14N spins in solids; the indirect detection method should produce high-resolution NMR spectra for 14N spins.Now, we are making a double resonance MAS probe which has two channels corresponding to a 14N resonance frequency and a 14N overtone frequency.

2003年，我们试图在动态角度旋转(DAS)核磁共振探头中提高转子的旋转频率。为此，我们制作了一些不同盖子的核磁共振转子，并使用这些转子驱动了DAS系统。然而，转杯纺丝的最大频率在6 kHz左右，不能使DAS系统在10 kHz以上的纺丝频率下切换纺丝轴。因此，我们采取了一种不同的策略来达到本研究的目的。首先，我们从理论上研究了多晶固体中^&lt；23&gt；Na核的泛音核磁共振间接检测。结果表明：当用不同的辐照频率进行泛音辐照时，如果将中心跃迁强度与辐照频率作图，可以得到固体中~(23)&gt；Na核的高分辨核磁共振谱。因此，上述间接检测方法适用于固体中的14N自旋；间接检测方法应产生高分辨率的14N自旋的核磁共振谱。现在，我们正在制作一种双共振MAS探头，它有两个通道，分别对应一个14N共振频率和一个14N泛音频率。

项目成果

Simulations of the 13C-14N REDOR NMR experiments performed with a frequency-sweep 14N overtone pulse

使用扫频 14N 泛音脉冲进行 13C-14N REDOR NMR 实验的模拟

• 发表时间: 2003
• 期刊: Chemical Physics Letters 377
• 作者: Daisuke Kuwahara;Yuya Yamazaki;Hajime Okamoto;Daisuke Kuwahara
• 通讯作者: Daisuke Kuwahara

Feasibility of the overtone NMR for half-integer quadrupolar nuclei

半整数四极核泛音核磁共振的可行性

• 发表时间: 2005
• 期刊: Chemical Physics Letters 414
• 作者: Daisuke Kuwahara;Yuya Yamazaki;Hajime Okamoto
• 通讯作者: Hajime Okamoto

Daisuke Kuwahara: "Simulations of the 13C-14N REDOR NMR experiments performed with a frequency-sweep 14N overtone pulse"Chemical Physics Letters. 377. 20-26 (2003)

Daisuke Kuwahara：“使用扫频 14N 泛音脉冲进行 13C-14N REDOR NMR 实验的模拟”《化学物理快报》。