全碳分子C_60/C_70的合成与分离

SYNTHESIS AND SEPARATION OF FULLERENES C_60/C_70

在自行设计制作的简单装置上,用电弧蒸发石墨的方法合成了C_60/C_70.冷凝的烟炱用苯萃取后得到棕黑色的固体产物,产率为9%,质谱分析表明,产物的全碳分子C_60与C_70之峰高比约为13比1.采用中性氧化铝柱色谱和石墨柱色谱分离C_60和C_70,均可获得99%以上的C_60纯品。实验证明,石墨柱色谱分离法是一个快速、简便而有效的分离大量样品的方法。

C_60/C_70 was synthesized by vaporizing graphite rods using self-designed apparatus. It was extracted from soot with benzene or toluene. After slowly evaporating the solution, a brown or black solid material was left. The yield was 9%. Mass spectroscopy shows that it contains mainnly C_60 and small amount of C_70. In transmitted light the crystals appear red-brown in color and have some kinds of crystallinic forms. The mixture of C_60/C_70 was subjected to column chromatography using neutral alumina or graphite. Column chromatography on neutral alumina with n-hexane as eluent gave satisfactory separation in miligran quantitics. Pure factions containing C_60 (>99%) were obtained. Column chromatography on graphite with n-hexane-toluene as eluents gave an excellent separation in more than 100 milligran quantitics. Pure fractions containing C_80 (>99%) were obtained quickly. The result showed that improved column chromatography on graphite is a simple and effective separation mothed to obtain the pure C_60.