Femtosecond studies of the influence of solvent on chemical reaction dynamics

在该项目中，由化学部实验物理化学计划资助，Bradforth将通过飞秒紫外泵浦探测光谱在215至300纳米的波长范围内对液体溶液中的化学反应动力学进行研究。 其目的是表征溶剂如何通过动态效应如笼化和能量耗散来修改和控制嵌入式小分子溶质的反应性。该项目包括几个任务，包括：1）开发平衡自由基（如CN、I和I*）的电子光谱和重取向动力学的基准信息; 2）通过双电荷溴化铜阴离子和相关铜体系的电荷转移到溶剂的脱离研究由电子喷射引发的溶质振动相干性;和3）ICN和BrCN的光解离研究，以探索键断裂的性质，从而探索碎片的大的旋转能量释放最初是如何耗散的。 拟议的工作是针对测试溶液动力学的基本理论，并提供在复杂介质中的反应的分子图像的更大的目标。 这项研究将与学生和博士后研究助理进行。

In this project, funded by the Experimental Physical Chemistry Program of the Chemistry Division, Bradforth will perform research on the chemical reaction dynamics in liquid solutions by means of femtosecond ultra violet pump-probe spectroscopy over the wavelength range from 215 to 300 nanometers. The objective is to characterize how solvents modify and control the reactivity of embedded small molecule solutes by dynamical effects such as caging and energy dissipation. The project consists of several tasks, including 1) development of benchmark information on the electronic spectra and reorientation dynamics of equilibrated radicals such as CN, I, and I*; 2) the investigation of solute vibrational coherences initiated by electron ejection via the charge-transfer-to-solvent detachment of the doubly-charged copper bromide anion and related copper systems; and 3) photodissociation studies of ICN and BrCN to explore the nature of bond breaking and thus how the large rotational energy release of the fragments is initially dissipated. The proposed work is directed toward the larger goal of testing fundamental theories of solution kinetics, and providing a molecular picture for reactions in complex media. This research will be conducted with students and postdoctoral research associates.