2021年11月11日 · Successful monitoring of the ortho-selective nitration of aniline has been demonstrated using the 14 N NMR protocol developed in this paper, which will help realize the visualization of nitration processes in the industry.

2023年3月23日 · 氮元素的基本信[1]：14N 的天然丰度为 99.63%， 自旋为1，四极矩为2.044fm2（相对比较大），共振频率36.1 MHz/500MHz。 15N 的天然丰度为 0.364%，自旋为1/2，共振频率为50MHz/500MHz。

2016年1月1日 · This chapter is devoted to the recent advances in 14 N solid-state NMR related to both theoretical and practical aspects. First, the last NMR methods developed to facilitate the direct or indirect detection of 14 N signals are presented in a succinct and comprehensive way.

14 N NMR. The 1D 14 Nitrogen NMR experiment is much less sensitive than Proton (1 H) but has a much larger chemical shift range. Its signals are broadened by quadrupolar interactions. The larger the molecule and the more asymmetric the nitrogen's environment, the broader the signal.

2011年11月1日 · An overtone NMR signal was first observed from 14 N by Creel et al., who studied a sample of hexamethylenetetramine (HMT) using CW NMR [118]. They showed that the overtone signal frequency was equal to the sum of the individual fundamental frequencies as would be expected.

2024年2月1日 · In this study, we conducted experimental investigations to assess the spin dynamics of 14 N OT using the rotational-echo saturation-pulse double-resonance (RESPDOR) sequence, which monitors population transfer induced by a 14 N OT pulse. The 14 N OT spin dynamics is well represented by a model of a two-energy-level system.

In this work, we present 14 N– 1 H HMQC magic-angle spinning (MAS) NMR experiments in the solid state as a promising tool to study amorphous formulations.

14 N NMR Spectroscopy of NH 4+ is a convenient and sensitive probe of structure and mobility in Nafion, Dow and Neosepta cation-exchange membranes. NH 4+ ions bound to these commercially produced membranes give rise to small 14 N …

2016年9月19日 · 14 N ultra-wideline solid-state NMR (SSNMR) spectra were obtained for 16 naturally occurring amino acids and four related derivatives by using the WURST–CPMG (wideband, uniform rate, and smooth truncation Carr–Purcell–Meiboom–Gill) pulse sequence and frequency-stepped techniques.

2017年5月17日 · We propose two broadband pulse schemes for 14 N solid-state magic-angle-spinning (MAS) nuclear magnetic resonance (NMR) that achieves (i) complete population inversion and (ii) efficient excitation of the double-quantum spectrum using low-power single-sideband-selective pulses.