Photochemistry and Photophysics of Metal Complexes

无机化学、生物无机化学和金属有机化学计划支持过渡金属络合物光谱和动力学领域的研究。向弗吉尼亚大学的詹姆斯·N·德马斯提供了一笔赠款，用于这一领域的调查和购买仪器，以促进研究。这一研究结果对太阳能转换、发光传感器以及新型发光探针的设计和应用具有直接的意义。将研究Ru(II)、Os(II)、Ir(III)和Re(I)光敏剂的分子间和分子内环境相互作用。将使用不同的技术来研究状态有序和衰变路径的变化，包括稳态、脉冲和相位瞬变发光光谱、核磁共振光谱和结晶学。特别是，分子内烷基链折叠回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，含有联吡啶配体和具有长n-烷基的腈的Re(I)配合物的发光性质随腈的亚甲基数目的增加而发生强烈的变化。这种现象涉及分子状态的转换，只需添加一个亚甲基即可。这一效应将有助于理解影响光化学和光物理的环境因素。这项工作将有助于合理设计适用于包括微多相系统在内的各种环境的位置选择性分子探针。

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.