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.

本课题由化学系化学结构、动力学和机理B项目资助，由英国剑桥大学的James K.密歇根州立大学化学系的McCusker将探索过渡金属基络合物电子结构的某些方面如何在其光诱导化学性质中表现出来。正在研究的具体方面是电子自旋，这是人们广泛熟悉的许多性质的起源（例如，磁性），但其对光化学反应性的影响尚未阐明。为了实现这一目标，该研究计划将涉及一系列化学系统的合成和表征，这些化学系统的设计旨在使系统的自旋特性与它们所表现出的光诱导特性之间建立明确的相关性。在有机合成和无机合成以及实验物理化学的界面上工作，这项研究将为学生提供一个肥沃的训练基地，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，同时发展基本的新见解，了解如何利用原子结构的一个非常基本的组成部分来创造新的分子功能，用于各种潜在的光-角动量守恒是自然界的基本属性。虽然它对分子科学的某些方面的影响是众所周知的，但这项研究计划提出了以下问题：这个概念在光诱导化学过程中的表现程度如何？为了解决这个基本问题，研究将涉及合成一系列基于过渡金属的供体-受体络合物，其自旋性质可以通过明智地选择单个金属离子（例如，用Co（III）替换Cr（III））或通过利用与海森堡交换耦合多核金属簇的自旋梯相关的温度依赖性。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，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电子物理学中表现出来，目的是展示如何考虑这些效应，从而提出新的方法，用于开发使用自旋作为设计特征的组合平台，以创建和操纵光电子。该奖项反映了NSF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。