Photoinitiated charge transfer in tailor-made molecules studied with 100 kilohertz two-dimensional white-Light spectroscopy

使用 100 kHz 二维白光光谱研究定制分子中的光引发电荷转移

基本信息

批准号：
1665110
负责人：
Martin Zanni
金额：
$ 45.2万
依托单位：
University of Wisconsin-Madison
依托单位国家：
美国
项目类别：
Standard Grant
财政年份：
2017
资助国家：
美国
起止时间：
2017-07-15 至 2020-06-30
项目状态：
已结题

来源：
https://www.nsf.gov/awardsearch/showAward?AWD_ID=1665110&HistoricalAwards=false
关键词：
Photoinitiated charge transfer tailor made

项目摘要

In this project funded by the Chemical Structure Dynamics and Mechanism-A (CSDM-A) program of the Chemistry Division, Professor Martin T. Zanni of the University of Wisconsin-Madison is studying charge transfer in tailor-made molecules using a new technique called two-dimensional white-light (2D WL) spectroscopy. Charge transfer processes play a central role in chemistry, such as for delivering electrons to speed up chemical reactions. A detailed understanding of charge transfer is difficult, because one must know the structures of the molecules, how much energy they contain, and how fast the electrons transfer from one place to another. Professor Zanni is addressing this challenge by studying a series of tailor-made molecules with well-defined and systematically varied structures. This series of molecules is being synthesized by the research group of Professor Michael Wasielewski at Northwestern University. Since these molecules absorb light of different colors, Professor Zanni uses white light spectroscopy to study the energy levels of the molecules and the rates of charge transfer. White light is a combination of all other colors of visible light. Absorption spectra are graphic descriptions of how atoms or molecules absorb light of different colors (wavelengths). By exciting the molecules with brief light pulses separated from each other by a few hundred femtoseconds (a femtosecond is one quadrillionth of a second), Professor Zanni is able to generate two-dimensional spectra, which look like topographical maps, and provide clues about how charge and energy are moving within or between molecules. The insights provided by this research may advance our understanding of charge transfer processes in living systems, and may have implications for the design of materials relevant to solar energy technologies. Professor Zanni and his group are involved in various activities focused on the public science education. They give presentations at the Wingra Elementary School Science Night and host an Research Experiences for Undergraduates (REU) high school teacher as part of their research dissemination plan. Professor Zanni and his group have also designed and prepared a televised lecture for Wisconsin Public Television on transitioning technologies from university research into the commercial sphere.A series of custom-made molecules are being studied by the Zanni research group using a 2D WL spectroscopy technique developed by this group. The series of molecules, prepared by the Wasielewski group, is designed to vary the electronic couplings and charge-transfer character in a systematic way. One set of compounds are caged complexes designed to capture and deliver multiple charges for use in multielectron redox reactions. Another set are bridged dimers of terrylene and perylene diimide, held in specific geometries. The bridged dimer systems have systematically controlled electronic couplings relevant to charge transfer in singlet fission. Two dimensional WL spectroscopy uses continuum generation for the pulse sequence, creating spectra that span nearly the entire visible and near-IR region of the spectrum. White-light is much weaker than the output of an optical parametric amplifier (OPA), and so the spectrometer is paired to a 100 kHz laser source and a shot-to-shot pulse shaper. With a broad spectral range and high signal-to-noise, this 2D WL spectrometer is well-suited for studying Professor Wasielewski's compounds. Initial 2D WL spectra contain cross peaks that reveal charge-transfer transitions that were previously unobserved in absorption spectra, uncovering the photophysical pathway for charge transfer in these compounds. The sensitivity of this 100 kHz spectrometer is so high that the final aim of this research is to implement it as a microscopy tool to measure spatially resolved 2D WL spectra. This research may extend our understanding of charge transfer and to develop new optical technologies. The experiments made possible by the combination of these tailor-made molecules and new 2D WL spectroscopy may overcome existing challenges and extend the understanding of charge transfer in chemistry.

在化学司的化学结构动力学和机制（CSDM-A）计划资助的项目中，威斯康星大学麦迪逊分校的Martin T. Zanni教授使用一种称为二维白光（2D WL）光学的新技术研究了裁缝分子中的电荷转移。电荷传输过程在化学中起着核心作用，例如传递电子以加快化学反应的速度。对电荷传输的详细了解很困难，因为必须知道分子的结构，它们所含能量的数量以及电子从一个地方传递到另一个位置的速度。 Zanni教授正在通过研究具有定义明确且系统多样化的结构的一系列量身定制的分子来应对这一挑战。西北大学的迈克尔·韦斯列夫斯基（Michael Wasielewski）教授合成了这一系列分子。由于这些分子吸收了不同颜色的光，因此Zanni教授使用白光光谱研究分子的能级和电荷转移速率。白光是所有其他颜色可见光的组合。吸收光谱是原子或分子如何吸收不同颜色（波长）光的图形描述。通过激发短暂的光脉冲彼此分离的分子，几百个飞秒（飞秒是四分之一的四分之一），Zanni教授能够产生二维光谱，它们看起来像是地形图，并提供有关在分子之间或分子之间移动或在分子之间移动的线索。这项研究提供的见解可能会提高我们对生活系统中电荷转移过程的理解，并可能对与太阳能技术相关的材料的设计产生影响。 Zanni教授及其小组参与了针对公共科学教育的各种活动。他们在Wingra小学科学之夜进行演讲，并为他们的研究传播计划的一部分主持了本科生（REU）高中老师的研究经验。 Zanni教授和他的小组还为威斯康星州公共电视台设计并准备了一场电视演讲，内容涉及从大学研究到商业领域的过渡技术。Zanni Research Group使用该组开发的2D WL Spectroscopy Technique研究了一系列定制分子。由WasieLewski组制备的一系列分子旨在以系统的方式改变电子耦合和电荷转移特征。一组化合物是笼子复合物，旨在捕获和输送多个电荷，以用于多电体氧化还原反应。另一组是特定几何形状的二烯和二酰亚胺二酰亚胺的桥接二聚体。桥接的二聚体系统具有系统控制的电子耦合，与单线裂变中的电荷转移相关。二维WL光谱法对脉冲序列使用连续产生，从而创造了几乎整个光谱的整个可见和近乎IR区域的光谱。白光比光学参数放大器（OPA）的输出弱得多，因此光谱仪与100 kHz激光源和射击脉冲塑形器配对。该2D WL光谱仪非常适合研究Wasielewski教授的化合物。最初的2D WL光谱包含交叉峰，这些横峰揭示了电荷转移过渡，这些转变以前在吸收光谱中未观察到，从而发现了这些化合物中电荷转移的光物理途径。该100 kHz光谱仪的敏感性非常高，以至于这项研究的最终目的是将其作为显微镜工具实施，以测量空间解决的2D WL光谱。这项研究可能会扩展我们对电荷转移的理解，并开发新的光学技术。这些量身定制的分子和新的2D WL光谱的结合使实验成为可能，可以克服现有的挑战，并扩展对化学中电荷转移的理解。

项目成果

期刊论文数量（9）

专著数量（0）

科研奖励数量（0）

会议论文数量（0）

专利数量（0）

Impact of non-equilibrium molecular packings on singlet fission in microcrystals observed using 2D white-light microscopy

DOI：
10.1038/s41557-019-0368-9
发表时间：
2020-01-01
期刊：
NATURE CHEMISTRY
影响因子：
21.8
作者：
Jones, Andrew C.;Kearns, Nicholas M.;Zanni, Martin T.
通讯作者：
Zanni, Martin T.

Two-Dimensional Electronic Spectroscopy Reveals Excitation Energy-Dependent State Mixing during Singlet Fission in a Terrylenediimide Dimer

DOI：
10.1021/jacs.8b08627
发表时间：
2018-12-26
期刊：
JOURNAL OF THE AMERICAN CHEMICAL SOCIETY
影响因子：
15
作者：
Mandal, Aritra;Chen, Michelle;Wasielewski, Michael R.
通讯作者：
Wasielewski, Michael R.

Enhancing the signal strength of surface sensitive 2D IR spectroscopy

DOI：
10.1063/1.5065511
发表时间：
2019-01-14
期刊：
JOURNAL OF CHEMICAL PHYSICS
影响因子：
4.4
作者：
Petti, Megan K.;Ostrander, Joshua S.;Zanni, Martin T.
通讯作者：
Zanni, Martin T.

Dual spectral phase and diffraction angle compensation of a broadband AOM 4-f pulse-shaper for ultrafast spectroscopy

用于超快光谱的宽带 AOM 4-f 脉冲整形器的双光谱相位和衍射角补偿

DOI：
10.1364/oe.27.037236
发表时间：
2019
期刊：
Optics Express
影响因子：
3.8
作者：
Jones, Andrew C.;Kunz, Miriam Bohlmann;Tigges-Green, Isabelle;Zanni, Martin T.
通讯作者：
Zanni, Martin T.

Heterogeneous Amyloid β-Sheet Polymorphs Identified on Hydrogen Bond Promoting Surfaces Using 2D SFG Spectroscopy