NMR diffusion spectroscopy for the characterization of multicomponent hydrogen-bonded assemblies in solution
NMR diffusion spectroscopy for the characterization of multicomponent hydrogen-bonded assemblies in solution
复制标题
用于表征溶液中多组分氢键组装体的核磁共振扩散光谱
DOI：
10.1039/b003968n
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发表时间：
2000
期刊：
影响因子：
--
通讯作者：
Y. Cohen
中科院分区：
文献类型：
--
作者：
P. Timmerman;J. Weidmann;K. Jolliffe;L. J. Prins;D. Reinhoudt;S. Shinkai;L. Frish;Y. Cohen
对 10 种不同的多组分氢键组件进行 NMR 扩散测量，即三个单玫瑰花结 SR1–SR3 ( 13· 2a3, 13· 2b3, 13· 2c3) 双玫瑰花结 DR1–DR5 ( 3a3· 2a6, 3b3· 2b6, 3c3· 2a6, 3d3· 2a6, 3e3· 2a6) 和 DR6 ( 4a3· 16)和四玫瑰花TR(53·2a12)被描述。上述一些玫瑰花结先前已使用已建立的表征技术（1H NMR 光谱、X 射线衍射和 Ag+ 标记后的 MALDI-TOF MS）被鉴定为明确定义的组件（即 SR1、DR1–DR3 和 TR）。研究了这些组件的扩散系数，并将其用作识别三个新组件（DR4-DR6）的参考，使用其他表征工具无法明确地确定其表征。当使用 DR1 作为参考时，实验扩散系数与计算扩散系数之间存在良好的相关性。从扩散数据计算出的有效水解半径与从气相最小化结构中提取的有效水解半径之间获得了相对较好的相关性，SR1和DR2除外。扩散测量表明，组装体 DR4 是热力学稳定的物质，而组装体 DR5 和 DR6 稳定性较差，并且仅存在较小程度。
NMR diffusion measurements on 10 different multicomponent hydrogen-bonded assemblies, viz. the three single rosettes SR1–SR3 ( 13· 2a3, 13· 2b3, 13· 2c3) the double rosettes DR1–DR5 ( 3a3· 2a6, 3b3· 2b6, 3c3· 2a6, 3d3· 2a6, 3e3· 2a6), and DR6 ( 4a3· 16), and the tetrarosette TR ( 53· 2a12) are described. Some of the above rosettes have been previously identified as well-defined assemblies (viz. SR1, DR1–DR3, and TR) using established characterization techniques (1H NMR spectroscopy, X-ray diffraction, and MALDI-TOF MS after Ag+-labeling). The diffusion coefficients of these assemblies were studied and used as a reference for the identification of three new assemblies ( DR4–DR6), the characterization of which could not be established unequivocally using other characterization tools. A good correlation was found between the experimental and calculated diffusion coefficients when DR1 was used as a reference. A relatively good correlation was obtained between the effective hydrolytic radii calculated from the diffusion data and those extracted from gas phase-minimized structures with SR1 and DR2 being exceptions. The diffusion measurements show that assembly DR4 is a thermodynamically stable species, while assemblies DR5 and DR6 are less stable and only present to a minor extent.