Detection and use of small J couplings in solid state NMR experiments

详细信息    查看全文

• 作者：Dominique Massiot ; Franck Fayon ; Michael Deschamps ; Sylvian Cadars ; Pierre Florian ; Valé ; rie Montouillout ; Nadia Pellerin ; Julien Hiet ; Aydar Rakhmatullin ; Catherine Bessada
• 关键词：NMR ; High resolution solid-state NMR ; J coupling ; Dipolar interaction
• 刊名：Comptes Rendus Chimie
• 出版年：2010
• 出版时间：January-February 2010
• 年：2010
• 卷：13
• 期：1-2
• 页码：117-129
• 全文大小：968 K

文摘

Over the years, solid-state nuclear magnetic resonance (NMR) spectroscopy has become an important tool for materials science, with its local point of view that is highly complementary to the structural information provided by diffraction techniques, electron microscopy, and molecular modeling, for example. As compared to other interactions that determine the spectral expression of the local structure of the observed nuclei in solid-state NMR experiments, the J coupling, characteristic of the chemical bonds, has received far less attention because of its being generally so small that it is masked in the line-widths. Nevertheless, the scalar or isotropic part of J couplings, which is not averaged by magic angle spinning (MAS), can be evidenced in many systems, and exploited to unequivocally characterize the extended coordination sphere. In a first step we describe the different experiments that permit the observation and the measurement of J couplings, even when dealing with quadrupolar nuclei. We then present new and recently-published results that illustrate the state of the art of NMR methodologies based on or intended for measuring J couplings in solids and the novel perspectives that they open towards better understanding of ordered and disordered materials at the subnanometric scale, a length scale that is otherwise difficult to access.