摘要
本文结合团簇反应动力学实验和量子化学计算,研究了O_(2)在金团簇阳离子上的吸附与活化.实验发现,在温和条件下,Au_(10)^(+)能快速吸附单个O_(2)分子形成Au_(10)O_(2)^(+);Au_(2)^(+)和Au_(4)^(+)的反应性则较低,但相应的氩络合物Au_(2)ArO_(2)^(+)和Au_(4)Ar_(1,2)O_(2)^(+)很容易形成;除此之外,其他尺寸的团簇都表现出反应惰性.理论计算表明,O_(2)倾向于以端接的方式吸附在具有线型或平面型结构的Au_(n)^(+)(n=2~7)簇和Au_(8)^(+)的平面异构体上,并表现出极低的活化程度吸附在具有三维结构的Au_(n)^(+)(n=9,11,13)簇上的O_(2)也呈现出类似的特征。与此形成鲜明对比的是,在Au_(8)^(+)的三维异构体和n=10,12,14的偶数大尺寸Au_(n)^(+)上,O_(2)倾向于以侧向桥接的方式吸附并被高度活化.理论预测的O_(2)在团簇上的键合强度结合动力学因素影响,合理地解释了实验中观察到的反应产物Au_(2,4,10)O_(2)^(+),Au_(2)ArO_(2)^(+)和Au_(4)ArO_(2)^(+).
We explored the adsorption of O_(2) on cationic gold clusters by combining cluster reaction experiments and theoretical calculations.Under a mild condition,Au_(10)^(+)can readily adsorb one O_(2) molecule forming Au_(10)O_(2)^(+);Au_(2)^(+)and Au_(4)^(+)are low-reactive,while the argon complexes Au_(2)ArO_(2)^(+) and Au_(4)Ar_(1,2)O_(2)^(+)can easily form;all other sizes are inactive.Theoretical calculations indicate that the O_(2) on the linear or planar structures of Aun+(n=2–7)and the planar isomers of Au8+tends to be adsorbed in an end-on manner and non-activated,and so does the O_(2) on the large odd sizes of Aun+with n=9,11,and 13 determined to be three-dimensional structures.In marked contrast,the O_(2) on the three-dimensional isomer of Au8+and the large even-numbered Aun+with n=10,12,and 14 tends to be adsorbed in a side-on manner and apparently activated.Observation of only Au_(2,4,10)O_(2)^(+),Au_(2)ArO_(2)^(+),and Au_(4)ArO_(2)^(+)in the present experiments can be well rationalized using the calculated bonding strengths and the kinetic factors.
作者
胡瑾
黄璐璐
刘文
金正千
王雪峰
邢小鹏
Jin Hu;Lulu Huang;Wen Liu;Zhengqian Jin;Xuefeng Wang;Xiaopeng Xing(Departement of Chemistry,Tongji University,Shanghai 200092,China)
基金
This work was supported by the National Natural Science Foundation of China(No.22273065 and No.21673158)
Science&Technology Commission of Shanghai Municipality(14DZ2261100).
关键词
金簇阳离子
飞行时间质谱仪
密度泛函理论
O_(2)活化
Cationic gold cluster
Time-of-flight mass spectrometer
Density functional theory
O_(2)activation
