Spectroscopic properties of transition metal compounds: detailed experiments under variable conditions

这一应用的主要研究主题是发现和详细表征过渡金属化合物和由含有过渡金属中心的分子构建块构建的材料的电子结构。该计划将提供对许多基本化学性质的见解，并对现代材料科学的几个领域做出贡献，重点是开发具有微调光学、电子或磁性性质的材料。它为所有级别的学生提供了一个具有挑战性、激动人心的培训环境，在化学核心概念、化学直觉和定量测量之间建立了令人着迷的联系。*我们使用配位化学技术来准备我们的目标系统，并应用一些光学光谱技术来洞察它们的电子基态和激发态。我们最近增加的仪器包括可变压力测量装置，我们目前正在安装新的仪器，用于皮秒时间范围内的时间分辨发光和瞬时吸收光谱。用电子光谱的含时理论和电子结构计算等现代理论方法对实验光谱结果进行了分析。计算的分子几何构型，如键长和键角，以及计算的振动频率，与在不同温度和压力下的实验结晶学结果和振动光谱进行了比较。光谱理论-结构相结合的方法将使我们能够理解和调整从金属-配体键合到分子间相互作用的各种效应。*我们期待通过压力调整或温度变化，对环境对嵌入过渡金属化合物的定量影响有重要的新见解。这些信息与传感器或发光材料的设计有关。该计划的一个关键长期目标是通过不断变化的条件来发现和了解趋势，而不是根据不同化合物的光谱进行传统的趋势内插，在这种情况下，由于许多性质和参数同时变化，因此很难确定观察到的变化的具体物理来源。

The main research theme of this application is the discovery and detailed characterization of the electronic structure of transition metal compounds and materials built from molecular building blocks containing transition metal centers. This program will provide insight on many fundamental chemical properties and contribute to several areas of modern materials science, focusing on the development of materials with fine-tuned optical, electronic or magnetic properties. It provides a challenging, stimulating training environment for students at all levels, establishing fascinating links between concepts at the heart of chemistry, chemical intuition and quantitative measurements.******We use techniques of coordination chemistry to prepare our target systems and apply a number of optical spectroscopic techniques to obtain insight on their electronic ground and excited states. Recent additions to our instrumentation include setups for variable-pressure measurements and we are currently installing new instrumentation for time-resolved luminescence and transient absorption spectroscopy in the picosecond time range. Experimental spectroscopic results are analyzed with modern theoretical methods, such as the time dependent theory of electronic spectroscopy and electronic structure calculations. Calculated molecular geometries, such as bond lengths and angles, and calculated vibrational frequencies are compared to experimental crystallographic results and vibrational spectra at variable temperature and pressure. The combined spectroscopic theoretical-structural approach will allow us to understand and tune effects ranging from metal-ligand bonding to intermolecular interactions.******We anticipate significant new insight on the quantitative influence of the environment on embedded transition metal compounds through pressure tuning or temperature variation. This information is relevant to the design of sensors or luminescent materials. A key long-range goal of this program is the discovery and understanding of trends through continuous variation of conditions, as opposed to the traditional interpolation of trends from spectra for different compounds, where it is much harder to identify specific physical origins of the observed variations because many properties and parameters are varied simultaneously.