Inter- and Intramolecular Interactions of Luminescent Metal Complexes

该奖项为弗吉尼亚大学化学系James N. Demas博士对d6二亚胺配合物的光物理研究提供了无机、生物无机和有机金属项目的持续支持。该项目的总体目标是为特定的分子位点开发合理设计的发光分子探针。他将研究长疏水烃链的邻近性对d6金属中心发射性质的影响。他还将研究嵌入DNA的发光配合物，特别强调由于多个键合位点的荧光识别，以及探针与DNA结合时的旋转重定向。在研究过程中，Demas将评估时间分辨相敏发射在表征环境对激发态特性影响方面的有效性。稳态，脉冲和相荧光法，以及核磁共振和晶体学，将用于检查在状态排序和发光Ru(II), Os(II), Ir（II）和Re(I)光敏剂的衰变路径的变化。发光金属配合物的电子结构对局部分子环境的变化很敏感。当这种复合物与DNA等物质结合时，它们的电子特性可能会因位置或位置的对称性而改变。相反，可以设计复合物来检测某些位点的存在。在这个项目中，将测试一种新技术的灵敏度，该技术可以检测探针由于其分子环境而产生的荧光变化。此外，还将研究疏水环境的变化对金属配合物发光性能的影响。该项目对传感器技术以及用于DNA和其他手性生物聚合物的结构和动力学的新探针的设计和应用具有重要意义。

This award provides continued support from the Inorganic, Bioinorganic, and Organometallic Program for studies of the photophysics of d6 diimine complexes by Dr. James N. Demas, Chemistry Department, University of Virginia. The overall goal of the project is to develop rationally designed luminescent molecular probes for specific molecular sites. He will investigate the effect of the proximity of a long hydrophobic hydrocarbon chain on the emission properties of the d6 metal center. He will also study luminescent complexes intercalated into DNA with special emphasis on identification of fluorescence due to multiple bonding sites, and the rotational reorientation of the probe while bound to DNA. In the course of the study, Demas will assess the effectiveness of time resolved phase sensitive emission in characterizing environmental effects on excited state properties. Steady-state, pulsed, and phase fluorimetry, as well as NMR and crystallography, will be used to examine variations in state ordering and decay paths of luminescent Ru(II), Os(II), Ir(II), and Re(I) photosensitizers. %%% The electronic structure of luminescent metal complexes is sensitive to changes in local molecular environment. When such complexes are bound to species like DNA, their electronic characteristics may be modified by the location or the symmetry of the site. Conversely, complexes can be designed to detect the presence of certain sites. In this project, the sensitivity of a new technique to detect changes in the flouresence of the probe due to its molecular environment will be tested. In addition, the effect of changes in the hydrophobic environment on the luminescence of the metal complex will be investigated. The project has implications for sensor technology and for the design and application of new probes for the structure and dynamics of DNA and other chiral biopolymers.