Charge Transfer/Transport in Molecular Systems: Three Challenging Problems

西北大学的马克·拉特纳（Mark Ratner）获得了化学理论、模型和计算方法项目的一项奖励，用于研究分子系统中电子转移（ET）的理论方法。这项工作主要有三个重点：1)。用悬浮在其中的可氧化还原位点的聚合物或半导体或金属量子点构成的杂化材料中ET的研究。核心挑战是将聚合物宿主的动力学与整体运输联系起来。2)。扩展了描述局部原子间对分子内整体电子电流的贡献的方案，以处理非弹性行为，极化子形成，振动和光子效应，以及一般的退相干。3)。紧结金属在1、2和3维的自能解析形式的发展。PI和他的同事们试图了解电极之间分子的不同几何形状是如何导致不同的传导模式的。例如，电流总是通过单个分子，还是在到达阳极之前在分子之间通过？这项工作对我们对包括光化学和电子系统在内的电子转移（ET）的许多情况的理解具有广泛的影响。鉴于ET的主要意义，太阳能捕获和储存装置以及环境稳定性的应用将直接来自这项工作。拉特纳参与了许多推广和教育活动，包括共同指导西北大学的可持续发展和能源倡议（http://www.isen.northwestern.edu/）。基于能源在社会中的重要性和兴趣，他还在计划新方法，既教授一年级化学课程，又开展社区外展讲座。

Mark Ratner of Northwestern University is supported by an award from the Chemical Theory, Models and Computational Methods program to carry out research on the development of theoretical methods for the study of electron transfer (ET) in molecular systems. There are three major thrusts for the work: 1). Investigation of ET in hybrid materials constructed of polymers with redox-available sites suspended within them, or with semiconductor or metal quantum dots. The central challenge is relating the dynamics of the polymeric host with the overall transport. 2). Extension of the scheme for describing local inter-atomic contributions to the overall electron currents within the molecule to deal with inelastic behavior, with polaron formation, with vibrational and photonic effects, and with decoherence in general. 3). Development of analytic forms for self-energies for tight-binding metals in 1, 2 and 3 dimensions. The PI and his coworkers try to understand how differing geometries of molecules between electrodes result in different conduction patterns. For example, does current always go through a single molecule, or does it pass between molecules before exiting at the anode? The work has broad impact on our understanding of a number of situations involving electron transfer (ET) including photochemical and electronic systems. Given the dominant significance of ET, applications to devices for solar energy capture and storage and to environmental stability will follow directly from this work. Ratner is involved in a number of outreach and educational activities, including codirecting the Initiative for Sustainability and Energy at Northwestern (http://www.isen.northwestern.edu/). He is also planning new approaches both to teaching first-year chemistry courses and to giving community outreach talks, based on the importance and interest of energy within the society.