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

波士顿大学的Amy Mullin得到了实验物理化学项目的资助，继续并扩展了她对内能对高激发多原子分子的碰撞弛豫和反应性的影响的研究。脉冲紫外激光吸收将用于激发分子，瞬态红外吸收将监测内部能量分布，以确定能量传递和反应截面。要进行的具体研究有：(1)超弹性碰撞（吡嗪与二氧化碳）的能量依赖性，(2)猝灭物质对碰撞弛豫（吡嗪与吡啶与水和二氧化碳）的影响，(3)利用轨迹计算确定猝灭物质（(1)与吡啶、2-吡啶和2,6-吡啶与水）的能量增益的理论建模，以及(4)激发对化学反应活性（苯与一系列自由基）的影响。活化分子在化学和生物化学中对反应性的影响是多方面的。这项工作将展示激光辐射对分子的特定激发如何消散，影响反应速率，并在反应产物中表现为激发。这些数据将用于测试分子中能量松弛的理论。

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.