Reactions of Highly Excited Molecules: From Supercollisions to Super-reactions?

波士顿大学的艾米·穆林得到了实验物理化学项目的资助，继续并扩大了她对内能对高激发多原子分子碰撞弛豫和反应性的影响的研究。脉冲紫外光吸收将被用来激发分子，瞬时红外吸收将监测内部能量分布，以确定能量转移和反应截面。将进行的具体研究包括：(1)超弹性碰撞(二氧化碳与吡嗪)的能量依赖性，(2)猝灭物种对碰撞松弛的影响(吡嗪和吡啶与水和二氧化碳)，(3)超弹性松弛的理论模拟，使用轨道计算来确定猝灭物种((1)和吡啶，2-甲基吡啶和2，6-叶氨酸与水的体系)的能量增益，以及(4)激发对化学反应活性的影响(苯和一系列自由基)。活化分子在影响反应活性的多个水平上在化学和生物化学中发挥重要作用。这项工作将展示激光辐射对分子的特定激发如何消散，影响反应速度，并在反应产物中表现为激发。这些数据将被用来测试分子中的能量松弛理论。

Amy Mullin of Boston University is supported by a grant from the Experimental Physical Chemistry Program to continue and extend her studies of the effect of internal energy on collisional relaxation and reactivity for highly excited polyatomic molecules. Pulsed uv laser absorption will be used to excite the molecules and transient ir absorption will monitor the internal energy distributions to determine the energy transfer and reactive cross-sections. Specific studies to be conducted are: (1) energy dependence of super elastic collisions (pyrazine by carbon dioxide), (2) the influence of quenching species on collisional relaxation (pyrazine and pyridine by water and carbon dioxide), (3) theoretical modeling of superelastic relaxation using trajectory calculations to determine energy gain by the quenching species (the system in (1) and pyridine, 2-picoline and 2,6-lutidine with water) and (4) influence of excitation on chemical reactivity (benzene with a series of radicals).Activate molecules play an important role in chemistry and biochemistry at many levels in influencing the reactivity. This work will show how specific excitation of molecules by laser radiation can be dissipated, influence the rates of reactions and can appear as excitation in the reaction products. The data will be used to test theories of energy relaxation in molecules.