Kinetic and Thermodynamic Studies of Long Distance Electron Transfer Reactions

本文将对影响电子转移反应速率和效率的因素进行研究。通过测量光诱导电荷分离速率常数和随温度变化的发射光谱，以及计算电子转移的自由能，来评价间隔剂分离给体和受体基团的作用。皮秒光量热法将用于评价电子转移时焓和体积的变化。最后，通过溶剂电子耦合及其对结构刚性分子中电子转移的影响将被研究。将分析转移速率常数、电子耦合矩阵元素和溶剂带结构之间的关系。在许多化学反应中常见的一个过程是电子的快速转移。有了有机动力学项目的资助，布朗大学的马修·齐姆特教授将研究控制电子转移过程速率的因素，这一过程在万亿分之一秒内完成。影响电子转移的参数将使用特别设计的分子来研究，以便供体和受体基团之间的距离以及中间原子的身份和位置都是明确的。研究结果可能使设计分子系统使电子传递效率最大化成为可能。

An investigation of the factors which govern the rate and efficiency of electron transfer reactions will be conducted. The effect of spacers separating donor and acceptor groups will be evaluated by measuring photoinduced charge separation rate constants and emission spectra as a function of temperature and calculating free energies of electron transfer. Picosecond photocalorimetry will be used to evaluate enthalpy and volume changes which occur upon electron transfer. Finally, through-solvent electron coupling and its impact upon electron transfer will be investigated in structurally rigid molecules. Correlations between transfer rate constants, electronic coupling matrix elements, and solvent band structure will be analyzed. %%% A process which is common to a large number of chemical reactions is the rapid transfer of electrons. With this grant from the Organic Dynamics Program, Profssor Matthew Zimmt of Brown University will investigate the factors which govern the rate of electron transfer processes which are complete within a few trillionths of a second. The parameters which influence electron transfer will be investigated using molecules specially designed so that both the distance between donor and acceptor groups and the identity and positions of the intervening atoms are well-defined. The results of the study may make it possible to design molecular systems which will maximize electron transfer efficiency.