Ar·CO团簇光电离的实验和理论研究

利用同步辐射光电离质谱装置,测量了Ar·CO范德瓦尔斯 (van der Waals, vdW) 团簇的的光电离质谱和光电离效率曲线.将它们与CO分子的绝对光吸收光谱比较, 发现在13.9到14.6 eV能量范围内的Ar·CO⁺的光电离效率曲线主要反映了收敛到 CO⁺ (X²∑⁺, v'= 1,2和3) Rydberg系列和收敛到 CO⁺ (A²Π)的n= 3的振动序列(v'= 6–9)的特点; 在14.6–15.75 eV光子能量范围内的Ar·CO的光电离效率曲线主要反映了CO的光吸收特性. 然而,由于Ar和CO之间的相互作用,其中的5个重要的光谱结构发生了蓝移; 而在15.75–15.80 eV光子能量范围内的Ar-CO的光电离效率曲线,它的属性受到组分Ar和CO的共同影响. 与此同时,也从理论上计算了Ar·CO团簇的电离能、Ar·CO团簇和Ar·CO⁺ 团簇离子的离解能. 关键词： Ar·CO团簇 同步辐射 光电离

Experimental and theoretical study of Ar·CO cluster

The photoionization mass spectra and photoionization efficiency curves of Ar·CO clusters are obtained with synchrotron radiation mass spectrometry. By comparison with absolute photoabsorption spectra of CO, the photoionization efficiency curve of Ar·CO clusters in an energy region from 13.9 to 14.6 eV reflects mainly the properties of Rydberg series converging to the X²∑⁺ (v⁺= 1, 2 and 3) of CO⁺, and these of n= 3 vibration sequence of the series converging to the A²Π state of CO⁺. In the energy region from 14.6 to 15.75 eV, the curve reflects mainly the absorption property of CO, but its five strong peaks shift toward blue due to the interaction between Ar and CO. In an energy region from 15.75 to 15.80 eV, the curve reflects mainly the absorption properties of Ar and CO. At the same time, ionization energy of Ar·CO, and dissociation energies of Ar·CO and Ar·CO ⁺ are also calculated using the theory of quantum chemistry.