Single conformation spectroscopy and dynamics of multichromophore networks

有了这个奖项，化学系的化学结构，动力学和机制（CSDM-A）计划资助普渡大学的Timothy Zwier教授及其合作者研究影响大分子折叠方式的微妙分子间相互作用。 Zwier教授和他的团队使用复杂的技术将这些分子转化为气相，结合灵敏度极高的光谱方法，正在进行实验，以解开将这些分子的单一构象保持在特定几何形状中的微妙力量。 待研究的分子包括肽以及可用于电子材料的分子。从这些研究中获得的知识将为理论和计算化学家提供测试新计算方法准确预测引起特定构象的微妙分子间力的能力的基准。 该项目的一个独特之处是与中西部的一些合成和理论化学家以及主要是本科院校的教师和学生合作。Zwier教授和他的研究小组使用各种方法，包括激光解吸（中性）和电喷雾电离（离子），在气相中制备中性和带电形式的大分子的低温样品。 使用能够分离单个构象异构体的光谱的各种激光光谱方法来询问物种的光谱。 正在研究的特定种类包括：形成螺旋的肽，形成平行和反平行β-折叠的肽，参与缠结网络形成的富含谷氨酰胺或天冬酰胺的肽，以及被认为在淀粉样蛋白原纤维形成中起作用的特定六肽。 除了肽，Zwier和他的团队正在研究孤立的环对苯（纳米环）的光谱，这些光谱被预测具有有趣的电子振动耦合。 Zwier研究小组正在与从合成化学家到理论和计算化学家的各种研究人员合作。 这项研究的影响是显着扩大通过与一些教师和本科生的合作，从小型文理学院，包括希望学院，卡拉马祖学院和威斯康星州-欧克莱尔大学。

With this award, the Chemical Structure, Dynamics and Mechanisms (CSDM-A) Program of the Division of Chemistry is funding Professor Timothy Zwier of Purdue University and his collaborators to investigate the subtle intermolecular interactions that influence the ways in which large molecules fold up on themselves. Using sophisticated techniques to get these molecules into the gas phase, combined with exquisitely-sensitive spectroscopic methods, Professor Zwier and his group are doing experiments that will unravel the delicate forces that hold single conformations of these molecules in their specific geometries. Molecules to be studied include peptides as well as molecules that may find use in electronic materials. The knowledge obtained from these studies will provide theoretical and computational chemists with benchmarks for testing the ability of new computational methods to accurately predict the subtle intermolecular forces that give rise to particular conformations. A unique element in this project is the collaboration with a number of synthetic and theoretical chemists as well as with faculty and students at primarily undergraduate institutions in the Midwest.Professor Zwier and his research group make low-temperature samples of neutral and charged forms of large, conformationally-flexible molecules in the gas-phase using a variety of methods including laser-desorption (neutrals) and electro-spray ionization (ions). The species' spectra are interrogated using a variety of laser spectroscopic methods that are capable of separating the spectra of individual conformers. Specific species that are being examined include: peptides that form helices, peptides that form parallel and anti-parallel beta-sheets, glutamine- or asparagine-rich peptides that are involved in the formation of tangled networks, and specific hexapeptides that are believed to play a role in the formation of amyloid fibrils. In addition to the peptides, Zwier and his group are studying the spectra of isolated cycloparaphenylenes (nano-hoops) that are predicted to have interesting vibronic coupling. The Zwier research group is collaborating with a wide variety of researchers from synthetic chemists to theoretical and computational chemists. The impact of this research is significantly broadened through the collaboration with a number of faculty and undergraduate students from small liberal arts colleges, including Hope College, Kalamazoo College and the University of Wisconsin - Eau Claire.