分子氧对变量温度的29Si MAS NMR光谱上的分子氧的影响 酸盐-酸盐复合物的酸盐-酸盐复合物的NMR光谱
Colin A Fyfe1, Darren H Brouwer
1Department of Chemistry, University of British Columbia, 2036 Main Mall, Vancouver, British Columbia, Canada V6T 1Z1. fyfe@chem.ubc.ca
Journal of the American Chemical Society
|February 5, 2004
概括
超磁性分子氧扩大了29Si MAS NMR光谱在焦酸盐复合体中. 用气去除氧气显著提高了光谱分辨率,有助于结构的确定.
科学领域:
- 材料科学 材料科学 材料科学
- 固态化学 固态化学
- 核磁共振光谱学 核磁共振光谱学
背景情况:
- 固态NMR对于确定热酸盐宿主-客体复合物的结构至关重要.
- 低温往往导致29Si MAS NMR光谱扩大,阻碍了详细的结构分析.
研究的目的:
- 在低温下调查低酸盐-酸盐复合物的29Si MAS NMR光谱中线路扩展的原因.
- 确定改善光谱分辨率以准确确定结构的方法.
主要方法:
- 固态29Si魔力角度旋转 (MAS) 核磁共振 (NMR) 光谱. 固态29Si魔力角度旋转 (MAS) 核磁共振 (NMR) 光谱.
- 可变温度NMR研究分析29Si T1和T2放松时间.
- 样品处理包括用气净化以去除氧气.
主要成果:
- 29Si峰值扩大与29Si T2放松时间直接相关.
- 岩道内的磁性分子氧被确定为放松和线路扩张的首要来源.
- 气净化显著改善了p-dibromobenzene/ZSM-5复合物的光谱分辨率.
- 对29Si T1放松时间的分析表明,氧气定位在ZSM-5的曲折道中.
结论:
- 分子氧显著影响了热酸盐复合物的固态NMR光谱的质量.
- 移除氧气是一种有效的策略,可以提高光谱分辨率,并使精确的结构确定.
- 观察到的氧气定位表明p-dibromobenzene位于ZSM-5通道交叉点.
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