...
  • 主题
高级搜索  >
历史搜索 清空历史
首页> 外文期刊>The journal of physical chemistry, C. Nanomaterials and interfaces >Density Functional Study of the ~(13)C NMR Chemical Shifts in Single-Walled Carbon Nanotubes with Stone—Wales Defects
【24h】

Density Functional Study of the ~(13)C NMR Chemical Shifts in Single-Walled Carbon Nanotubes with Stone—Wales Defects

机译：具有石—威尔缺陷的单壁碳纳米管中〜（13）C NMR化学位移的密度泛函研究

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

The ~(13)C NMR chemical shifts of (7,0), (8,0), (9,0), and (10,0) single-walled carbon nanotubes (SWNTs) with Stone—Wales (SW) defects have been studied computationally using a gauge-including projector-augmented plane-wave (GIPAW) density functional theory (DFT) method. A SW-defect substantially broadens the NMR signal of a particular tube, however, in general the average shift of the non-defect carbons does not differ greatly from that of the pristine species. "Parallel" orientations of the defect site yields shifts at around 150—160 ppm from atoms in the defect site which are separated from the rest of the NMR signal. Therefore, the results indicate that ~(13)C NMR might be able to detect the presence of, and perhaps even quantify the concentration of SW defects found in SWNTs. Differences in the NMR obtained for two defect orientations are analyzed by comparing the shifts of the defect atoms with those of planar and bent structures of the azupyrene molecule. Representative visualizations for the shielding tensors of the (8,0) SWNT with and without defects are also reported.
机译：具有Stone-Wales（SW）缺陷的（7,0），（8,0），（9,0）和（10,0）单壁碳纳米管（SWNT）的〜（13）C NMR化学位移已使用包括投影仪的增强平面波（GIPAW）密度泛函理论（DFT）方法进行了计算研究。 SW缺陷实质上加宽了特定试管的NMR信号，但是，通常，无缺陷碳的平均位移与原始物种的平均位移相差不大。缺陷部位的“平行”取向使缺陷部位的原子在大约150-160 ppm处发生位移，这些原子与NMR信号的其余部分分开。因此，结果表明〜（13）C NMR可能能够检测SWNT中发现的SW缺陷的存在，甚至量化。通过比较缺陷原子与金刚zu分子的平面和弯曲结构的位移，分析了在两个缺陷方向上获得的NMR差异。还报告了具有和不具有缺陷的（8,0）SWNT屏蔽张量的代表性可视化。

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