二维R-C_(60)聚合物的核磁共振波谱研究

NMR studies of two-dimensional R-C_(60)polymer

合成了二维rhombohedral(2D)-R)相C_(60)聚合物,对其固体核磁共振(NMR)波谱进行了详细的讨论.^(13)C固体核磁共振魔角谱(^(13)C MAS NMR)上δ145附近的sp^2杂化峰出现展宽并伴有边带,并且在δ72附近出现了一个相对较弱的新的峰.这表明通过[2+2]加环反应在邻近C_(60)分子之间形成了sp^3杂化共价键,使得C_(60)分子球笼上出现了五个位置不等价的sp^2杂化碳原子,导致位于δ145附近的sp^2杂化峰展宽.利用拟合分峰的方法得出了这五个不等价的碳原子的峰的位置,分别位于δ134.6、δ139.6、δ145.1、δ147.9以及δ149.1,这五个不等价的碳原子数目上的比例关系和核磁共振曲线的积分面积吻合.

A rhombohedral two-dimensional （2D-R） C60 polymer has been synthesized and the 13 C Magic angle spinning nuclear magenatic resonance（13C MAS NMR） data has been discussed detailedly. By using 13C MAS NMR, the writers were able identify two resonances, the broad and intense sp2 resonance around δ145 which has two sidebands, and a small new one at δ72. It indicates that sp3 bonds have been formed between adjacent fullerene molecus via [2＋2] cycloaddition reaction, leading to the inequivalent sp2 carbons on C60 cage. The former line has been broadened and has several components due to this inequivalent sp2 carbons. By simulating and spitting of the line at 8145, five isotropic components were shown at 8134.6, 8139.6, 8145.1, 8147.9 and 8149.1, and the numbers of the inequivalent sp2 carbons neatly dovetailed with the integral areas of the every line.