Prelude to Hot Chemistry: Preliminary Studies on the Collisional Dynamics of Highly Vibrationally Excited Molecules

波士顿大学的艾米·穆林博士得到了化学部实验物理化学项目的支持，并获得了研究计划补助金，以研究高振动激发的多原子分子的碰撞和反应动力学。这些物种将通过紫外激光激发，然后快速内转换到基电子态的高振动能级。初步研究将集中在振动激发的吡嗪或吡啶与二氧化碳和水之间的能量转移。将测量产品状态分布和绝对横截面。最终，将进行实验，以调查高水平的内部激发推动原本没有反应的系统越过激活障碍的能力。大多数化学反应发生在反应物的基电子态上。较大的激活势垒可以阻止反应发生，即使系统处于高温下。在这个项目中，穆林教授将使用激光激发来填充这些分子的高振动能级，对应于3000K的振动温度，这个温度通常会分解分子。这种制备方法允许大量能量存在于反应物中而不会分解它，并通过提供足够的能量来克服活化势垒来增强反应。

Dr. Amy Mullin of Boston University is supported by the Experimental Physical Chemistry Program of the Chemistry Division with a Research Planning Grant to study the collisional and reactive dynamics of highly vibrationally excited polyatomic molecules. These species will be prepared by ultraviolet laser excitation followed by rapid internal conversion to high vibrational levels of the ground electronic state. Preliminary studies will concentrate on energy transfer between vibrationally excited pyrazine or pyridine with carbon dioxide and water. Product state distributions and absolute cross sections will be measured. Ultimately, experiments will be conducted to investigate the ability of high levels of internal excitation to drive otherwise unreactive systems over an activation barrier. Most chemical reactions take place on the ground electronic states of the reactants. Large activation barriers can prevent reactions from taking place, even when the systems are at elevated temperatures. In this project, Professor Mullin will use laser excitation to populate high vibrational levels of these molecules, corresponding to vibrational temperatures of 3000K, a temperature which would normally decompose the molecule. This method of preparation allows a large amount of energy to be present in the reactant without decomposing it and enhances the reaction by providing enough energy to overcome the activation barrier.