Vigren Erik, Kamińska Magdalena, Hamberg Mathias, Zhaunerchyk Vitali, Thomas Richard D, Semaniak Jacek, Danielsson Mathias, Larsson Mats, Geppert Wolf D
Department of Physics, AlbaNova, Stockholm University, SE-106 91, Stockholm, Sweden.
Phys Chem Chem Phys. 2007 Jun 14;9(22):2856-61. doi: 10.1039/b700649g. Epub 2007 Apr 3.
Dissociative recombination of the deuterated acetaldehyde ion CD3CDO(+) has been studied at the heavy-ion storage ring CRYRING, located at the Manne Siegbahn Laboratory, Stockholm, Sweden. Product branching fractions together with absolute DR cross-sections were measured. The branching fractions were determined at a relative collision energy between the ions and the electrons of approximately 0 eV. With a probability of 34% the DR events resulted in no ruptures of bonds between heavy atoms (i.e. no breakage of the C-C bond or the C[double bond, length as m-dash]O bond). In the remaining 66% of the events one of the bonds between the heavy atoms was broken. The energy-dependent cross-section for the DR reaction was measured between approximately 0 and 1 eV relative kinetic energy. In the energy region between 1 meV and 0.2 eV the absolute cross section could be fitted by the expression sigma(E) = 6.8 x 10(-16)E(-1.28) cm(2), whereas in the energy interval between 0.2 and 1 eV the data were best fitted by sigma(E) = 4.1 x 10(-16)E(-1.60) cm(2). From these cross section data the thermal rate coefficient (as a function of the electron temperature), alpha(T) = 9.2 x 10(-7) (T/300)(-0.72) cm(3) s(-1) was obtained.
在位于瑞典斯德哥尔摩曼内·西格巴恩实验室的重离子储存环CRYRING上，对氘代乙醛离子CD3CDO(+)的离解复合进行了研究。测量了产物分支比以及绝对离解复合截面。分支比是在离子与电子之间相对碰撞能量约为0 eV时测定的。离解复合事件中有34%的概率不会导致重原子之间的键断裂（即C - C键或C = O键不会断裂）。在其余66%的事件中，重原子之间的其中一个键会断裂。在相对动能约为0至1 eV之间测量了离解复合反应的能量相关截面。在1 meV至0.2 eV的能量区域，绝对截面可以用表达式σ(E) = 6.8×10⁻¹⁶E⁻¹·²⁸ cm²拟合，而在0.2至1 eV的能量区间，数据最好用σ(E) = 4.1×10⁻¹⁶E⁻¹·⁶⁰ cm²拟合。根据这些截面数据，得到了热速率系数（作为电子温度的函数），α(T) = 9.2×10⁻⁷ (T/300)⁻⁰·⁷² cm³ s⁻¹ 。
