高等学校化学学报

高等学校化学学报 ›› 2000, Vol. 21 ›› Issue (4): 581.

• 论文 • 上一篇    下一篇

碳/磷二元团簇的激光溅射产生、光解及结构研究

曾嵘, 刘剑波, 韩春英, 高振   

  1. 分子科学中心, 分子反应动力学国家重点实验室, 中国科学院化学研究所, 北京 100080
  • 收稿日期:1999-02-02 出版日期:2000-04-24 发布日期:2000-04-24
  • 通讯作者: 高　振(1938年出生),男,研究员,从事无机团簇研究.
  • 基金资助:

    国家自然科学基金(批准号:29773054)

Formation by Laser Ablation, Photodissociation and Structure Analysis of C/P Binary Clusters

ZENG Rong, LIU Jian-Bo, HAN Chun-Ying, GAO Zhen    

  1. Center of Molecular Sciences, State Key Laboratory of Molecular Reaction Dynamics, Institute of Chemistry, Chinese Academy of Sciences, Beijing 100080, China
  • Received:1999-02-02 Online:2000-04-24 Published:2000-04-24

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被引次数

16

摘要： 在串级飞行时间质谱仪上用532nm激光溅射碳/磷混合样品,所得团簇分为两类:碳/磷二元团簇离子和纯碳团簇离子.纯碳团簇离子的相对强度随样品中磷含量的增加而变强,说明磷对纯碳团簇离子的形成具有重要作用.而在所形成的碳/磷二元团簇中,正离子主要有CnP2+(0<n<30),CnP3+(0<n<22)两类,而负离子则较多,有CnP-(0<n<20),CnP2-(0<n<30),CnP3-(n为2—30间的偶数)、CnP5-(n为2—20间的偶数)四类,但没有CnP4-.CnP2+团簇离子的激光光解结果表明,其主要光解通道为剥落一个磷原子.用B3LYP/6-31G**对CnP2的结构进行分析,确定磷在两端的直线型链状结构为最稳定的结构.此稳定结构与团簇的光解结果相吻合.此外用同样的方法得到的CnP2的电离能(PI)和电子亲合能(EA)出现了奇偶变化的现象,与实验结果相符合.

关键词: 激光溅射, 碳/磷二元团簇, 飞行时间质谱, 密度泛函B3LYP

Abstract: C/P binary clusters were produced by direct laser ablation of C/P mixed sample on a time of flight mass spectrometer. These clusters can be divided into two groups, C/Pbinary clusters and pure carbon clusters. The intensity of pure carbon clusters became stronger with the increase of Pin mixed sample, which indicates that Phas an important influence on the formation of pure carbon clusters. In C/Pbinary clusters, the compositions of the positive ions are only Cn P2+(0< n <30), Cn P3+(0< n <22), while the negative ions are more abundant than positive ions, which have compositions of Cn P-(0< n <20), Cn P2-(0< n <30), Cn P3-( n is even number in 2—30), Cn P5-( n is even number in2—20), but no Cn P4- was produced. The photodissociation of Cn P2+ indicates that their main photodissociation channel was the loss of one Patom. Combining photodissociation and DFTcalculations(B3LYP/631G**), the most stable structure of C6P2 positive ions should be the linear chain structure with Patoms at each end of the molecule.

Key words: Laser ablation, C/P binary clusters, Time of flight mass spectrometry, Density, Function B3LYP

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