Multidimensional Spectroscopy of Exciton Dynamics

激子动力学的多维光谱

• 批准号: 220404594
• 负责人: Professor Dr. Tobias Brixner
• 金额: --
• 依托单位: Institut für Physikalische und Theoretische Chemie
• 依托单位国家: 德国
• 项目类别: Research Units
• 财政年份: 2012
• 资助国家: 德国
• 起止时间: 2011-12-31 至 2018-12-31
• 项目状态: 已结题
• 来源: https://gepris.dfg.de/gepris/projekt/220404594?language=en
• 关键词: Multidimensional; Spectroscopy; Exciton; Dynamics

Coherent two-dimensional (2D) and higher-dimensional spectroscopy of electronic excitations provides detailed information on the time-dependent dynamics of complex systems. Making use of the analysis of nonlinear signals with respect to multiple frequency axes it is possible to separate contributions that overlap in one-dimensional spectra. We have the following objectives: The technique of 2D spectroscopy shall be further developed to implement fast shot-to-shot data acquisition under the magic angle (i.e., avoiding anisotropy contributions). With that we will investigate the excitonic dynamics in molecular aggregates. In a perylene-based J-aggregate (cooperation with Prof. Würthner), H-bonds lead to a unique arrangement of the chromophores in a "cable-like" double-strand structure that can be varied systematically by changing the substituents. We want to determine the excitonic signatures as a function of structure via 2D spectroscopy as well as power-dependent measurements. The fast 2D data acquisition should further allow us to follow the time-dependent evolution of excitonic couplings during the kinetic process of selfaggregation. In another project part (cooperation with Prof. Lambert) we want to investigate the origin of long-lived coherences that are discussed controversially in the literature on 2D spectroscopy. Squarain oligomers are suited as model systems because there the most intense absorption of the one chromophore overlaps spectrally with the vibrational shoulder of the other chromophore. Besides linear oligomers we will also address ring- and star-shaped structures because the selection rules for optical transitions change with the different symmetries, in turn modifying the channels accessible for excitonic energy transfer. In yet another part of the project we will develop a technique that is new in the literature and that we call "2D micro-spectroscopy" allowing additional spatial resolution in a confocal microscope. Thus we shall investigate microcrystalline molecular aggregates on surfaces that exhibit locally varying excitonic properties (cooperation with Prof. Pflaum). The last project part centers on theoretical analysis. Besides cooperations with the theory groups (Prof. Engel, Prof. Engels, Prof. Mitric) we want to develop a new procedure for extracting population transfer rates from 2D spectra. In the literature one models elaborately, for this purpose, the molecular system, simulates the dynamics, from that calculates the nonlinear response and the observable signal, compares the result with experiment, and finally improves the model assumptions iteratively. Instead, we strive for a direct "inversion" of the experimental raw data. We want to adapt for 2D spectroscopy the principle of "target analysis" known from transient absorption and combine it with a systematic "Aufbau principle".

相干二维（2D）和更高的电子激发维光谱提供了详细的信息，复杂系统的时间相关的动力学。利用相对于多个频率轴的非线性信号的分析，可以分离在一维频谱中重叠的贡献。我们的目标是：进一步发展二维光谱技术，实现魔角下的快速炮间数据采集（即，避免各向异性贡献）。在此基础上，我们将研究分子聚集体中的激子动力学。在基于二萘嵌苯的J-聚集体（与Würthner教授合作）中，氢键导致发色团以“缆状”双链结构的独特排列，该结构可以通过改变取代基而系统地改变。我们希望通过2D光谱以及功率相关测量来确定激子签名作为结构的函数。快速的二维数据采集应进一步使我们能够遵循随时间变化的激子耦合过程中的动力学过程中的自聚集。在另一个项目部分（与Lambert教授合作）中，我们想研究在二维光谱学文献中有争议的长寿命相干态的起源。方蛋白低聚物适合作为模型系统，因为其中一个发色团的最强吸收与另一个发色团的振动肩在光谱上重叠。除了线性低聚物，我们还将解决环形和星形结构，因为光学跃迁的选择规则随不同的对称性而变化，从而修改了激子能量转移的通道。在该项目的另一部分，我们将开发一种新的技术，在文献中，我们称之为“二维显微光谱”，允许在共聚焦显微镜额外的空间分辨率。因此，我们将研究微晶分子聚集体表面表现出局部不同的激子性能（与教授合作。最后一部分是理论分析部分。除了与理论小组（Engel教授，Engels教授，Mitric教授）合作外，我们还希望开发一种从二维光谱中提取布居转移率的新方法。在文献中，为了这个目的，一个精心建模的分子系统，模拟动力学，从计算的非线性响应和可观察到的信号，比较结果与实验，并最终迭代地改进模型假设。相反，我们争取直接“反演”的实验原始数据。我们希望将瞬态吸收中的“目标分析”原理应用于二维光谱学，并将其与系统的“构造原理”联合收割机相结合。

项目成果

Generalized magic angle for time-resolved spectroscopy with laser pulses of arbitrary ellipticity

• DOI: 10.1088/0953-4075/47/12/124014
• 发表时间: 2014-06-28
• 期刊: JOURNAL OF PHYSICS B-ATOMIC MOLECULAR AND OPTICAL PHYSICS
• 影响因子: 1.6
• 作者: Schott，Sebastian;Steinbacher，Andreas;Brixner，Tobias
• 通讯作者: Brixner，Tobias

The role of the dipolar neighborhood on the relaxation dynamics of multichromophoric merocyanines.

偶极邻域对多发色部花青弛豫动力学的作用

• DOI: 10.1039/c6cp02437h
• 发表时间: 2016
• 期刊: Physical chemistry chemical physics : PCCP
• 作者: F. Koch;A. Steinbacher;C. Consani;A. Zitzler-Kunkel;M. Stolte;F. Würthner;T. Brixner
• 通讯作者: T. Brixner

Tracing the steps of photoinduced chemical reactions in organic molecules by coherent two-dimensional electronic spectroscopy using triggered exchange.

利用触发交换相干二维电子光谱追踪有机分子中光诱导化学反应的步骤

• DOI: 10.1103/physrevlett.110.148305
• 发表时间: 2013
• 期刊: Physical review letters
• 影响因子: 8.6
• 作者: S. Ruetzel;M. Kullmann;J. Buback;P. Nuernberger;T. Brixner
• 通讯作者: T. Brixner

Photoisomerization among ring-open merocyanines. II. A computational study.

开环部花青之间的光异构化 II 计算研究

• DOI: 10.1063/1.4881259
• 发表时间: 2014
• 期刊: The Journal of chemical physics
• 作者: C. Walter;S. Ruetzel;M. Diekmann;P. Nuernberger;T. Brixner;B. Engels
• 通讯作者: B. Engels

Similarities and differences in the optical response of perylene-based hetero-bichromophores and their monomeric units.

基于苝的异质双发色团及其单体单元光学响应的​​异同

• DOI: 10.1002/cphc.201300062
• 发表时间: 2013
• 期刊: Chemphyschem : a European journal of chemical physics and physical chemistry
• 作者: U. Selig;P. Nuernberger;V. Dehm;V. Settels;M. Gsänger;B. Engels;F. Würthner;T. Brixner
• 通讯作者: T. Brixner