Ballistic Energy Transport in Molecules

在化学系化学结构、动力学和机理a （CSDM-A）项目的支持下，杜兰大学的Igor Rubtsov教授和Alexander Burin教授领导的一个研究小组将研究弹道能量传输，这是一个负责分子中能量异常快速和有效运动的过程。能量以热的形式在物质中流动，这一过程被称为热扩散。然而，Rubtsov教授和他的研究小组之前发现了一些系统，在这些系统中，能量沉积在分子的一端，通过分子主干迅速转移到远处的位置。这个项目研究了这种异常能量传输的潜在细节。对弹道能量传输的更深入了解可能有助于科学家设计出具有更好的导热性能的新材料，在这种材料中，能量传输的方向、速度和效率都是可控的。该项目还为从事研究的研究生和本科生提供跨学科培训，并为来自代表性不足群体的中学生提供参与促进化学的教育活动的机会。该团队将在实验室中使用超快双频二维红外光谱方法，并将实施第一性原理理论建模，以阐明一系列低聚链中的能量传输的效率、速度和机制，从而有可能提供一个展示高效能量传输的大型分子系统库。这项研究的目的是了解振动波包的形成、传播和探测过程的化学和物理起源，这些波包代表了紧凑的能量束。该计划的一个重点是在较长的分子链中获得有效波包起始的制度，并探索实施这种制度的各种条件。另一个重点是研究低聚链中的电子共轭如何影响波包的起始、传输速度和传输效率，并探索通过外部刺激改变电子共轭程度来改变能量传输速度和效率的能力。这些研究的目标是开发有效的能量传输器和能量传输开关的设计原则。该项目的更广泛影响包括高级学生培训，为来自科学领域代表性不足的群体的学生提供研究机会，以及为中学生提供额外的教育推广活动。该奖项反映了美国国家科学基金会的法定使命，并通过使用基金会的知识价值和更广泛的影响审查标准进行评估，被认为值得支持。

With support from the Chemical Structure, Dynamics, and Mechanisms-A (CSDM-A) Program in the Division of Chemistry, a research team led by Professors Igor Rubtsov and Alexander Burin at Tulane University will investigate ballistic energy transport, a process that is responsible for unusually rapid and efficient movement of energy in molecules. Energy, in the form of heat, typically flows through materials through a process called thermal diffusion. However, Professor Rubtsov and his research team previously identified systems where energy deposited in one end of a molecule is rapidly transferred through the molecular backbone to distant locations. This project examines the underlying details of this anomalous transport of energy. A deeper understanding of ballistic energy transport may help scientists design new materials with improved thermal conductivity properties where the direction, speed, and efficiency of energy transport are controlled. The project also provides interdisciplinary training for graduate and undergraduate students engaged in the research, as well as opportunities for middle school students from underrepresented groups to participate in educational activities that promote chemistry. The team will use ultrafast dual-frequency two-dimensional infrared spectroscopy methods in the laboratory and will implement first-principle theoretical modeling to elucidate the efficiency, speed, and mechanisms of energy transport in a range of oligomeric chains, potentially providing access to a large library of molecular systems that demonstrate efficient energy transport. The aim of the proposed research is to understand the chemical and physical origins of the processes of formation, propagation, and detection of the vibrational wavepackets, which represent compact bundles of energy. One focus of the program is to access regimes of efficient wavepacket initiation in longer molecular chains and to explore a variety of conditions for implementing such regimes. Another focus is to investigate how electronic conjugation in oligomeric chains affects the wavepacket initiation, transport speed, and transport efficiency and to explore the ability of altering the energy transport speed and efficiency by changing the degree of the electronic conjugation by external stimuli. These studies target the development of design principles for efficient energy transporters and energy transport switches. The broader impacts of the project include advanced student training, research opportunities for students from groups that are underrepresented in science, and additional educational outreach activities for middle school students.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.