Photophysics, Exciton and Charge Transport in Conjugated Organometallic Oligomers and Aggregates

这项由无机、生物无机和金属有机化学项目颁发的奖项支持佛罗里达大学的柯克·S·尚泽教授的研究，他致力于“共轭有机金属齐聚物和聚集体中的光物理学、激子和电荷传输”的研究。我们将研究含金属的pi共轭低聚物和超分子组件中的激发态性质以及电荷和激子输运。总的目标是发展一个清楚的了解激发态离域，能量和电荷传输在孤立的单链的有机金属pi共轭体系(分子线)内，以及由pi共轭单体自组装产生的超分子聚集体中。我们将研究几个分子体系。1)我们将研究一类含有反式(Ar-C=C-)2M(P-P)2基团(M=Ru和Os，P-P是双膦)的金属-乙炔低聚物，以确定控制有机金属PI共轭体系激发态离域的因素。2)为了确定激发态性质与碳链长度之间的关系，我们将在一系列反式，反式-Ar(P)2PT-(C=C)n-铂(P)2AR的铂(II)封端聚炔中探讨三重态激发态的性质。3)研究了一系列长链、单分散的铂-乙酰低聚物，测定了三重态激子和负极化子通过单一有机金属共轭链的输运速率。4)光物理和激子输运研究将扩展到定义明确的超分子聚集体，这些聚集体是由a)带有一个或多个长链烷基的pi-共轭刚性棒状铂-乙酰低聚物或b)带有金属络合物发色团的六苯并冠烯自组装而形成的。这项工作的目的将是确定聚集对三重态性质的影响，并研究定义良好的超分子聚集体中的三重态激子迁移。这项研究与具有巨大潜力的新兴技术直接相关，这些技术将造福社会、经济和提高国家的国防能力。具体地说，作为这项工作的重点的材料在光电子器件中有应用，如可见光和近红外发光二极管(新型光源)、光伏电池(光能转换)、非线性光学(激光保护和变色)和传感器(化学和生物制剂检测)。该项目也是本科生和研究生的主要研究培训渠道。佛罗里达大学的光与物质外联计划扩大了该项目的更广泛影响，通过该计划，PI、研究生和本科生将把与光化学相关的科学演示带到北佛罗里达地区的中学。

This award by the Inorganic, Bioinorganic and Organometallic Chemistry program supports research by Professor Kirk S. Schanze of the University of Florida to pursue studies on the "Photophysics, Exciton and Charge Transport in Conjugated Organometallic Oligomers and Aggregates." Excited-state properties along with charge and exciton transport in metal-containing pi-conjugated oligomers and supramolecular assemblies will be examined. The overall objectives are to develop a clear understanding of excited state delocalization, energy, and charge transport within isolated single chains of organometallic pi-conjugated systems (molecular wires) and within supramolecular aggregates produced by self-assembly of pi-conjugated monomers. Several molecular systems will be studied. 1) A family of metal-acetylide oligomers that contain repeat units consisting of trans-(Ar-C=C-)2M(P-P)2 moieties (M = Ru and Os, and P-P is a diphosphine) will be investigated in order to determine the factors that control excited state delocalization in organometallic pi-conjugated systems. 2) The nature of the triplet excited state will be probed in a series of platinum(II)-capped polyynes of the type, trans,trans-Ar(P)2Pt-(C=C)n-Pt(P)2Ar in order to define the relationship between excited state properties and carbon chain length. 3) A series of long-chain, monodisperse Pt-acetylide oligomers will be studied to determine the rates of triplet exciton and negative polaron transport through single organometallic conjugated chains. 4) Photophysical and exciton transport studies will be extended to well-defined supramolecular aggregates formed by self-assembly of a) pi-conjugated rigid-rod Pt-acetylide oligomers capped with one or more long alkyl chains, or b) hexabenzocoronenes functionalized with metal complex chromophores. The objective of this work will be to determine the effect of aggregation on the properties of the triplet state and to study triplet exciton migration in well defined supramolecular aggregates.This investigation is directly relevant to emerging technologies that have a significant potential to benefit society, the economy, and improve the nation's defense capabilities. Specifically, the materials that are the focuses of this work have applications in opto-electronic devices such as visible and near infrared light emitting diodes (novel light sources), photovoltaic cells (light to electrical energy conversion), non-linear optics (laser protection and color shifting) and sensors (chemical- and bio-agent detection). This program also serves as the primary research training conduit for undergraduate and graduate students. The broader impacts of this project are augmented by the Light and Matter Outreach program at the University of Florida, through which PI, graduate students and undergraduate students will bring photochemistry related scientific demonstrations to middle schools in the North Florida region.