Spin Effects on the Excited-state Dynamics of Transition Metal Complexes

自旋效应对过渡金属配合物激发态动力学的影响

• 批准号: 2154233
• 负责人: James McCusker
• 金额: $ 52.5万
• 依托单位: Michigan State University
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2022
• 资助国家: 美国
• 起止时间: 2022-04-01 至 2025-03-31
• 项目状态: 未结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=2154233&HistoricalAwards=false
• 关键词: Spin; Effects; Excited; state; Dynamics

In this project, funded by the Chemical Structure, Dynamics and Mechanisms B Program of the Chemistry Division, Professor James K. McCusker of the Department of Chemistry at Michigan State University will be exploring how certain aspects of the electronic structure of transition metal-based complexes manifest in their photo-induced chemical properties. The specific aspect being studied is electron spin, which is the origin of many properties that people are widely familiar with (e.g., magnetism) but whose influence on photochemical reactivity has not been elucidated. To achieve this goal, the research program will involve the synthesis and characterization of a range of chemical systems that have been designed to enable the establishment of a clear correlation between the spin properties of the system and the photo-induced properties that they exhibit. Working at the interface of synthetic organic and inorganic and experimental physical chemistry, the research will provide a fertile training ground for students to understand and appreciate the interconnection between these formally disparate subfields of chemistry while developing fundamental new insights into how a very basic component of atomic structure can be leveraged to create new molecular functionality for a wide variety of potential light-enabled applications.Conservation of angular momentum is a fundamental property of Nature. While its influence on certain aspects of molecular science are well known, this research program is asking the following: to what extent does this concept manifest in photo-induced chemical processes? To address this fundamental question, the research will involve the synthesis of a series of transition metal-based donor-acceptor complexes whose spin properties can be systematically varied, either by judicious choice of a single metal ion (e.g., replacement of Cr(III) by Co(III)) or by exploiting the temperature dependence associated with the spin ladder of a Heisenberg exchange-coupled polynuclear metal cluster. Characterization of the photo-induced electron and/or energy transfer dynamics will focus on steady-state and time-resolved spectroscopies, including variable-temperature ultrafast optical and x-ray methods. It is anticipated that the research will provide insight into how zero-field spin polarization manifests in the photophysics of molecular systems with the goal of demonstrating how consideration of these effects can suggest new approaches for the development of compositional platforms using spin as a design feature for creating and manipulating photo-induced molecular functionality.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.

在这项由化学系化学结构、动力学和机制B计划资助的项目中，密歇根州立大学化学系的詹姆斯·K·麦卡斯克教授将探索过渡金属化合物电子结构的某些方面如何体现在它们的光诱导化学性质中。目前正在研究的具体方面是电子自旋，它是人们广为人知的许多性质(如磁性)的来源，但其对光化学反应的影响尚未阐明。为了实现这一目标，该研究计划将涉及一系列化学体系的合成和表征，这些体系的设计使得能够在体系的自旋性质和它们表现出的光诱导性质之间建立明确的关联。这项研究将在合成有机和无机以及实验物理化学的界面上工作，为学生提供一个肥沃的训练场地，让他们了解和欣赏这些形式上不同的化学子领域之间的相互联系，同时对如何利用原子结构的一个非常基本的成分来为各种潜在的光驱动应用创造新的分子功能提供基本的新见解。角动量守恒是大自然的一项基本属性。虽然它对分子科学的某些方面的影响是众所周知的，但这个研究计划提出了以下问题：这个概念在光诱导的化学过程中体现到了什么程度？为了解决这一根本问题，本研究将涉及合成一系列基于过渡金属的给体-受体配合物，它们的自旋性质可以通过明智地选择单一金属离子(例如，用Co(III)取代Cr(III))或通过利用与Heisenberg交换耦合多核金属团簇的自旋阶梯相关的温度依赖性来系统地改变。光致电子和/或能量转移动力学的表征将集中在稳态和时间分辨光谱学，包括变温超快光学和X射线方法。预计这项研究将深入了解零场自旋极化如何在分子系统的光物理中表现出来，目的是展示考虑这些影响如何为使用自旋作为创建和操纵光诱导分子功能的设计特征的组成平台的开发提供新的方法。这一奖项反映了NSF的法定使命，并通过使用基金会的智力优势和更广泛的影响审查标准进行评估，被认为值得支持。