New Light on Late Transition Metal Complexes

这个项目，在无机，生物无机和有机化学计划，是关于阐明激发态弛豫的机制，在正方形平面，四配位络合物的铂（II）和铜（II）。 这项工作是基于早期的观察，这些化合物的激发态的寿命受到复合物与环境的次级相互作用的强烈影响。 因此，它们具有作为分子探针和传感器的潜力。 具体的研究将包括铂（II）三联吡啶和铜（II）卟啉配合物的光化学特性，无论是在流体介质中，并插入到DNA中，并试图增加前配合物的激发态寿命的三联吡啶配体通过取代改性。 将采用的技术将包括发光，吸收和CD光谱与淬火反应和温度相关的测量。 电磁辐射的吸收产生激发的电子状态，其可以通过非辐射（热生成）或辐射（光的发射）路径恢复（弛豫）到基态。 通过研究辐射弛豫化合物的发射光谱，可以获得有关其电子结构的大量信息。 辐射弛豫可以高度依赖于分子所处的环境，并且在有利的情况下，发射光谱的观察可以用作分子环境的探针。 该项目的主要目标是更好地了解某些过渡金属化合物激发态弛豫的发生方式以及这些弛豫如何由分子环境决定。 在许多领域有许多潜在的应用，包括光传感器、光动力学癌症治疗和分子电子学。

This project, in the Inorganic, Bioinorganic, and Organometallic Chemistry Program, is concerned with elucidation of the mechanisms of excited state relaxation in square planar, four- coordinate complexes of platinum(II) and copper(II). The work is based upon earlier observations that the lifetimes of excited states of such compounds are strongly affected by secondary interactions of the complexes with their environments. As a result they have potential as molecular probes and sensors. Specific studies will include characterization of the photochemistry of platinum(II) terpyridine and copper(II) porphyrin complexes both in fluid media and intercalated into DNA, and attempts to increase the excited state lifetimes of the former complexes by modification of the terpyridine ligand through substitution. Techniques to be employed will include luminescence, absorption and CD spectroscopies in conjunction with quenching reactions and temperature dependent measurements. Absorption of electromagnetic radiation generates excited electronic states that may revert (relax) to the ground state by non-irradiative (heat generating) or irradiative (emission of light) pathways. A great deal of information can be obtained about the electronic structure of compounds that undergo irradiative relaxation by studies of their emission spectra. Irradiative relaxation can be highly dependent upon the environment in which the molecule resides and under favorable circumstances the observation of an emission spectrum can be used as a probe of the molecular environment. This project has as its major objective the development of a better understanding of the ways in which relaxation of excited states of certain transition metal compounds occur and how these are determined by the molecular environment. There are many potential applications in a number of areas including photosensors, photodynamic cancer therapy, and molecular electronics.