Photochemistry and Photophysics of Metal Complexes

无机，生物无机和有机金属化学计划支持光谱和过渡金属配合物动力学领域的研究。拨款给弗吉尼亚大学的James N. Demas进行该领域的调查，并购买仪器以促进研究。这一研究成果对太阳能转换、发光传感器以及DNA等生物聚合物结构和动力学的新型发光探针的设计和应用具有直接意义。将研究Ru(II), Os(II), Ir（III）和Re(I)光敏剂上的分子间和分子内环境相互作用。在状态排序和衰减路径的变化将使用不同的技术进行检查，包括稳态和脉冲和相位瞬态发光光谱，核磁共振光谱和晶体学。特别是，分子内烷基链折叠到配合物的发光部分对激发态性质的新扰动将被研究。例如，含联吡啶配体和含长n-烷基的腈的铼(I)配合物的发光性质随腈的亚甲基数目的变化而有很大的变化。这种现象涉及到只需加入一个亚甲基就能改变分子状态。该效应将有助于理解影响光化学和光物理的环境因素。这项工作将有助于在包括微异质系统在内的各种环境中合理设计位点选择性分子探针。

The Inorganic, Bioinorganic and Organometallic Chemistry Program supports research in the area of spectroscopy and kinetics of transition metal complexes. A grant is made to James N. Demas of The University of Virginia for investigations in this field and for the purchase of instrumentation to facilitate the research. The results of this research have direct implication in solar energy conversion, luminescent sensors and the design and application of new luminescent probes of the structure and dynamics of biopolymers such as DNA. Inter- and intramolecular environmental interactions on Ru(II), Os(II), Ir(III) and Re(I) photosensitizers will be studied. Variations in state orderings and decay paths will be examined using different techniques including steady state and pulsed and phase transient luminescent spectroscopy, nuclear magnetic resonance spectroscopy and crystallography. In particular, the novel perturbation of excited state properties by intramolecular alkyl chain foldback onto the luminescent portion of the complex will be studied. For example, rhenium(I) complexes containing a bipyridyl ligand and a nitrile with a long n-alkyl group show a strong variation in luminescence properties with the number of methylene groups of the nitrile. This phenomenon involves molecular state switching with the addition of as little as one methylene. The effect will help understand environmental factors affecting photochemistry and photophysics. The work will contribute to the rational design of site selective molecular probes for a variety of environments including microheterogeneous systems.