Kinetics of Gas-Phase Ion Association and Dissociation

在这个实验物理化学项目中， 化学部门的罗伯特·邓巴（Robert Dunbar），凯斯西方公司的罗伯特·邓巴（Robert Dunbar） 储备大学将研究气相离子的性质 利用离子回旋共振与激光相互作用 离子阱 “中型至大型”碳氢化合物，有机金属 化合物、簇和络合离子是研究的目标。 时间分辨光解离动力学测量 受激离子辐射冷却率，红外多光子 离解动力学，辐射的测定 关联效率和振动的分配 复合离子离解产物中的能量都是 考察 其中一些的温度依赖性 将使用冷却到77 K的离子阱来确定过程。 理论研究将进行处理红外 多光子离解和辐射缔合 与精通统计力学的专家合作。 %%% 离子回旋加速器技术的发展 共振光谱学使科学家能够捕捉 带电的原子或分子，称为离子， 相对较长的时间，大约几秒或更长。 与 如此长的存储时间，涉及离子的各种过程， 现在可以更容易地研究。 这样的过程的示例包括离子在电离之后的分裂。 吸收光的能量刚好能切断 原子之间的键（近阈值光解离）和 红外辐射的发射。 邓巴教授的工作将 使他能够研究这些“缓慢”的化学过程 对于各种相当大的分子离子。

In this project in the Experimental Physical Chemistry Program of the Chemistry Division, Robert Dunbar of Case Western Reserve University will study the properties of gas-phase ions interacting with laser light using an ion cyclotron resonance ion trap. "Medium-to-large" hydrocarbons, organometallic compounds, clusters, and complex ions are targets for study. Time-resolved photodissociation kinetics, measurement of radiative cooling rates of excited ions, infrared multiphoton dissociation kinetics, the determination of radiative association efficiencies and of partitioning of vibrational energy in the products of complex ion dissociation will all be examined. The temperature dependence of some of these processes will be determined using an ion trap cooled to 77 K. Theoretical studies will be conducted dealing with infrared multiphoton dissociation and radiative association in conjunction with an expert versed in statistical mechanics. %%% The development of the technique known as Ion Cyclotron Resonance Spectroscopy has enabled scientists to trap electrically charged atoms or molecules, known as ions, for relatively long times, on the order of seconds or longer. With such long storage times, various processes involving ions which last up to seconds in time can now be studied more easily. Examples of such processes include the breakup of an ion after the absorption of light with just enough energy to sever the bonds between atoms (near-threshold photodissociation) and the emission of infrared radiation. Professor Dunbar's work will allow him to study several of these "slow" chemical processes for a variety of fairly large molecular ions.