摘要
采用电弧放电法制备内嵌镧金属富勒烯的原灰,通过改变氦气压力及电流强度来提高内嵌镧金属富勒烯产率。原灰由1,2,4-三氯苯提取并回溶入甲苯后,利用分析型高相液相色谱(HPLC)对提取液中各富勒烯组分进行分析。通过分别衡量3种常见含镧金属富勒烯La@C2v-C82、La@Cs-C82和La_2@C_(80)与C84的相对峰面积比,探讨了氦气压力和电流强度等对3种金属富勒烯产率的影响。实验结果表明,氦气压力与电流强度共同决定了金属富勒烯的产率,在(1)低电流高氦气压、(2)中等电流中等氦气压、(3)高电流低氦气压的条件下都可以高产率地获得含镧金属富勒烯。此外,调整电流强度和氦气压力可以改变La@C2v-C82和La@Cs-C82的相对比例。例如,在电流为100、120 A或氦气压为20、35 k Pa时,此前认为的"minor"异构体La@Cs-C82的含量甚至高于"major"异构体La@C2v-C82。还发现降低电流强度或减小氦气压力可促进La_2@C_(80)的生成,这表明La_2@C_(80)与La@C82的形成过程可能是不同的。
La-containing metallofullerenes were synthesized with a direct current arc-discharge method, and the experimental conditions such as helium pressure and current density were optimized to improve the yield of metallofullerenes （La@C2v-C82, La@Cs-C82 and La2@C80）. The raw soot was extracted by 1,2,4-trichlorobenzene and was then redissolved in toluene. The yields of the La-containing metallofullerenes were discussed based on the high performance liquid chromatographic results by comparing their peak areas with that of C84. Experimental results show that the high yield of La@C82 can be attributed to a synergetic effect of current density and He pressure, i.e. （1） low current and high He pressure; （2） medium current and medium He pressure; and （3） high current and low He pressure. Furthermore, the relative ratio of La@C2v-C82 and La@Cs-C82 can be adjusted by changing the current density and He pressure. Surprisingly, it is discovered that low current density or low He pressure facilitates the formation of La2@C80, indicating that the formation process of La2@C80 may be different from that of La@C82.
出处
《无机化学学报》
SCIE
CAS
CSCD
北大核心
2018年第2期295-299,共5页
Chinese Journal of Inorganic Chemistry
基金
国家自然科学基金(No.51472095,51602097,51672093)资助项目.
关键词
镧
金属富勒烯
电弧放电法
制备
提取
La
fullerene, metal｜ofullerene
arc-discharge
extraction
作者简介
通信联系人:卢兴,E-mail:lux@hust.edu.cn
