激光产生的碳原子簇负离子及其质谱研究(II)

近年来,尽管碳原子簇的合成与研究已成为非常热门的课题,但是对其负离子的研究却相对冷落了一些.两年多前,我们以激光在高真空中直接轰击单质碳样品的方式,产生了n≤441的C_n~-并通过对其质谱的分析确定了它们从链状至环状构型的转化.最近,我们又以同样方式产生了成簇原子数高于100的碳原子簇负离子,记录了它们的飞行时间质谱. 本实验选用的样品是光谱纯的碳粉,直接压入样品托座中的小坑.仪器的构造已有另文详细介绍,实验时仪器的主要工作参数与参考文献1] 中描述的基本相同,只是激光束

Mass Spectrometry of Laser Generated Negative Carbon Cluster Ions(II)

Mass spectrum of negative cluster carbon ions with cluster size up to 100 was recorded on a self-built laser plasma source time-of-flight mass spectrometer.For cluster anious larger than or equal to 50, only clusters with even size were observed. Thisobservation suggests that these cluster anions can also adopt the fullerene configura-tion and the configuration transition from planar ring to closed shell starts at n=50.Among these anions, C_(60)~- does not have special ion intensity.