Study of Intermolecular Interactions in the Corrole Matrix by Solid-State NMR under 100 kHz MAS and Theoretical Calculations
Study of Intermolecular Interactions in the Corrole Matrix by Solid-State NMR under 100 kHz MAS and Theoretical Calculations
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DOI：
10.1002/anie.201305475
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发表时间：
2013-12-23
影响因子：
16.6
通讯作者：
Pruski, Marek
中科院分区：
文献类型：
--
作者：
Kobayashi, Takeshi;Mao, Kanmi;Pruski, Marek
基于快速魔角旋转（MAS）[1]的固态（SS）NMR光谱方法的最新进展为少量（< 5 mg）天然丰度样品的结构研究提供了新的机会。利用穿透空间和穿透键极化转移，低g核的间接检测，以及适当的同质和异质解耦，可以以优异的灵敏度和分辨率测量此类样品的一维和二维（1D和2D）光谱。[2]然而，短程分子间秩序的确定往往仍然难以捉摸。这种分析可以通过研究利用大多数低g核（例如13 C或15 N）的大化学位移范围的异数相关性来很好地服务。事实上，异质结相关（HETCOR）NMR光谱和核间距离的测量，通常与理论计算相结合，提供了化学和生物学中复杂氢键系统，混合材料和主客体对的结构细节。[3]尽管如此，向低g核的分子间极化转移通常会受到低灵敏度的阻碍。一个很有前途的解决方案是通过homeplane 1H-1H 2D相关方法，如双量子（DQ）MAS [4]或自旋扩散（NOESY类）实验[5]，只要在两个维度上都达到足够的分辨率。一种可能的方法是使用1H CRAMPS解耦与快速MAS相结合，以提高这些实验中的分辨率。[6]超快MAS的研究进展（在100 kHz和更高[7]）提供了在没有RF去耦的情况下获得适当的1H分辨率的途径。在此，我们报告了在100 kHz的MAS下1H 2D SSNMR测量的第一个应用，其与间接检测的1H {13 C}和1H {15 N} HETCOR实验和理论计算结合使用以仔细检查主-客体内的相互作用（HG）体系（方案1）。
Recent progress in solid-state (SS) NMR spectroscopic methods based on fast magic angle spinning (MAS)[1] has enabled new opportunities for the structural study of small quantities (< 5 mg) of natural abundance samples. Utilizing throughspace and through-bond polarization transfer, indirect detection of low-g nuclei, and suitable homo-and heteronuclear decoupling, one-and two-dimensional (1D and 2D) spectra of such samples can be measured with excellent sensitivity and resolution.[2] However, determination of the short-range intermolecular order often remains elusive. Such analyses can be well-served by studying heteronuclear correlations that take advantage of the large chemical shift range of most low-g nuclei (for example, 13C or 15N). Indeed, heteronuclear correlation (HETCOR) NMR spectroscopy and measurements of internuclear distances, often in concert with theoretical calculations, have provided structural details of complex hydrogen-bonded systems in chemistry and biology, blended materials, and host–guest pairs.[3] Still, intermolecular polarization transfers to low-g nuclei are often hampered by low sensitivity. A promising solution to this challenge is offered by homonuclear 1H–1H 2D correlation methods, such as double-quantum (DQ) MAS [4] or spin-diffusion (NOESY-like) experiments,[5] provided that sufficient resolution is achieved in both dimensions. One of the possible approaches is the use of 1H CRAMPS decoupling in concert with fast MAS to boost resolution in these experiments.[6] The recent development of ultrafast MAS (at 100kHz and more [7]) provides access to appropriate 1H resolution without RF decoupling.Herein, we report the first application of 1H 2D SSNMR measurements under MAS at 100 kHz, which are used in combination with indirectly detected 1H {13C} and 1H {15N} HETCOR experiments and theoretical calculations to scrutinize the interactions within a host–guest (HG) system consisting of 5, 10, 15-tris (pentafluorophenyl) corrole 1, and toluene (Scheme 1).