...
  • 主题
高级搜索  >
历史搜索 清空历史
首页> 外文期刊>Coordination chemistry reviews >Tungsten-183 nuclear magnetic resonance spectroscopy in the study of polyoxometalates
【24h】

Tungsten-183 nuclear magnetic resonance spectroscopy in the study of polyoxometalates

机译：钨-183核磁共振波谱研究多金属氧酸盐

获取原文
获取原文并翻译 | 示例
           
页面导航
  • 摘要
  • 著录项
  • 相似文献
  • 相关主题

摘要

This review focuses on the tungsten-183 NMR spectroscopy of polyoxotungstates. The ~(183)W nuclide is the only NMR-active natural tungsten isotope with a spin of 1/2 and natural abundance of 14.3%. It gives rise to very narrow resonance lines. The NMR spectral envelope depends on the structure and symmetry of the anion. The ~(183)W chemical shifts are sensitive to their surrounding environment, including central atom, electric charge and size of adjacent elements, counterions in solution and solvent. The replacement of ligand atoms in an anion by the quadrupolar vanadium nucleus or by paramagnetic ions either in a ligand site or in the central site cause the resonance signals of the tungsten atoms adjacent to the substituted atoms to shift dramatically and broaden or even disappear. The spectral envelope, relative intensity of the lines and homonuclear and heteronuclear coupling constants provide the basis to identify anionic structure. Tungsten-183 NMR spectroscopy including 2-D COSY and 2-D INADEQUATE spectroscopy are used to distinguish new synthetic species, to examine product purity, to differentiate isomers and to establish new structures in solution as well as to monitor the progress of reaction. Tungsten-183 NMR spectroscopy has already become a powerful routine tool of structural characterization for polyoxotungstates in solution.
机译：这篇综述集中在聚氧钨酸盐的钨-183 NMR光谱学上。 〜（183）W核素是唯一的NMR活性天然钨同位素，其自旋为1/2，自然丰度为14.3％。它引起非常窄的共振线。 NMR谱图包络取决于阴离子的结构和对称性。 〜（183）W化学位移对其周围环境敏感，包括中心原子，电荷和相邻元素的大小，溶液和溶剂中的抗衡离子。阴离子中的配体原子被四极钒原子核或配体位点或中心位点的顺磁性离子置换，会导致与被取代原子相邻的钨原子的共振信号发生剧烈移动，并变宽甚至消失。光谱包络，谱线的相对强度以及同核和异核耦合常数为识别阴离子结构提供了基础。包括2-D COZY和2-D INADEQUATE光谱在内的Tungsten-183 NMR光谱用于区分新的合成物种，检查产物纯度，区分异构体并在溶液中建立新结构以及监测反应进程。钨183 NMR光谱已经成为溶液中多氧钨酸盐结构表征的强大常规工具。

著录项

相似文献

  • 外文文献
  • 中文文献
  • 专利
获取原文

客服邮箱：kefu@zhangqiaokeyan.com

京公网安备：11010802029741号 ICP备案号：京ICP备15016152号-6 六维联合信息科技 (北京) 有限公司©版权所有

  • 客服微信

  • 服务号