高分子化学位移的量化计算与固体NMR实验研究

波谱学杂志 ›› 2010, Vol. 27 ›› Issue (4): 597-608.

高分子化学位移的量化计算与固体NMR实验研究

徐璐¹，李宝会¹，孙平川^2*

1. 南开大学物理科学学院，天津 300071；
2. 南开大学功能高分子材料教育部重点实验室与化学学院，天津 300071

收稿日期:2010-02-09 修回日期:2010-04-22 出版日期:2010-12-05 发布日期:2010-12-05
基金资助:
国家杰出青年科学基金资助项目（20825416）.

Chemical Shift Anisotropy of Polypropylenes: Theoretical Calculation and Experimental Results from Solid-State NMR Experiments

XU Lu¹, LI Bao-Hui¹, SUN Ping-Chuan^2*

1. School of Physics, Nankai University, Tianjin 300071, China;
2. Key Laboratory of Functional Polymer Materials, Ministry of Education, Nankai University, Tianjin 300071, China

Received:2010-02-09 Revised:2010-04-22 Online:2010-12-05 Published:2010-12-05
Supported by:
国家杰出青年科学基金资助项目（20825416）.

摘要/Abstract

摘要：

该文以2种不同立构聚丙烯（iPP和sPP）为讨论对象，首先研究了量化计算方法在预测高分子¹³C 各向同性和各向异性化学位移（CSA）中的应用，然后讨论了近年来发展的测定¹³C CSA粉末线形的2种重要固体NMR实验技术（SUPER和RAI）的特点和实验优化问题. 最后，利用可获得接近无扭曲线形的SUPER技术测定了等规立构聚丙烯样品的¹³C CSA粉末线形，并与量化计算理论结果比较. 结果表明：¹³C 各向同性化学位移及CSA粉末线形的理论计算结果均与固体NMR实验结果有很好的符合，预示通过¹³C CSA量化计算结合固体NMR实验是阐明高分子微观结构的有力工具.

关键词: 量化计算, 固体NMR, 化学位移, 高分子, 聚丙烯

Abstract:

Chemical shift isotropy and anisotropy of isotactic and syndiotactic polypropylene (denoted as iPP and sPP, respectively) were predicted by quantum chemical calculation. ¹³C chemical shift anisotropy (CSA) powder patterns of iPP were successfully determined with the separation of undistorted powder patterns by effortless recoupling (SUPER) experiments. It was found that the results from quantum chemical calculation are in good accordance with that from solid-state NMR experiments. These results indicate that the combination of quantum chemical calculation and solid-state NMR experiment is a powerful tool in elucidating the microstructure of polymers. The two important solid-state NMR techniques for obtaining ¹³C CSA powder pattern, SUPER and recoupling of anisotropy information (RAI), were compared, with their advantages and disadvantages discussed using methylmalonic acid as a sample compound.

Key words: quantum chemical calculation, solid-state NMR, chemical shift, polymer, polypropylene

中图分类号:

O482.53

徐璐, 李宝会, 孙平川. 高分子化学位移的量化计算与固体NMR实验研究[J]. 波谱学杂志, 2010, 27(4): 597-608.

XU Lu, LI Bao-Hui, SUN Ping-Chuan. Chemical Shift Anisotropy of Polypropylenes: Theoretical Calculation and Experimental Results from Solid-State NMR Experiments[J]. Chinese Journal of Magnetic Resonance, 2010, 27(4): 597-608.

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