Collaborative Research: Investigating Structural Dynamic Coherences of Transition Metal Complexes in Photochemical Processes

合作研究：研究光化学过程中过渡金属配合物的结构动态相干性

• 批准号: 1362942
• 负责人: Felix Castellano
• 金额: $ 18万
• 依托单位: North Carolina State University
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2014
• 资助国家: 美国
• 起止时间: 2014-09-01 至 2017-12-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1362942&HistoricalAwards=false
• 关键词: Collaborative; Research; Investigating; Structural; Dynamic

In this project funded by Chemical Structure, Dynamics and Mechanisms program of Chemistry Division, Professors Lin Chen of Northwestern University and Felix Castellano of North Carolina State University are developing spectroscopic and synthetic methods to investigate how multiple metal centers in transition metal complexes (TMCs) act cooperatively to convert and accumulate energy from sunlight to multiple electronic potentials that ultimately will drive catalytic reactions for generating fuels. The proposed research is in line with the NSF Strategic and Performance Goals to transform the frontiers and innovate for society. The knowledge obtained through the proposed studies could be transformative for the chemical sciences and will greatly enhance our ability to rationally design chemical materials/devices for catalysis, optoelectronics and energy sustainability. The research activity engages university graduate students to use the advanced laser facility for characterization and advanced chemistry lab facilities for materials synthesis, providing them with a unique training ground for the development of multidisciplinary expertise. Such training is urgently needed for the next generation STEM workforce in order to explore the frontier of chemical science and to keep the US globally competitive at the frontiers of knowledge. The proposed research/education activities are integrated with public outreach and mentoring aimed at young scientists, including undergraduate students inside and outside of the University (especially female, minority, and underrepresented local college students) through collaborative training, summer school and education focused symposiums.This work aims at controlling materials processes at the level of electrons by engineering structural factors to influence intramolecular electronic interactions and system-bath interactions on the time scale of coherent electronic and atomic motions The mechanistic details enabling multiple-electron conversion will be investigated by newly developed two-dimensional electronic spectroscopy (2DES) and optical anisotropy spectroscopy applied to new molecular architectures. The proposed work aims at understanding intrinsic electronic couplings between the multiple metal centers TMCs and their influence on photochemical reactions. The work will engineer intrinsic coherent motions in a series of di-platinum complexes via systematically varying structural factors, such as the inter-platinum distances as well as the steric hindrance/energetics/size/conjugation of the ligands, resulting in systematic changes of the energy levels of the molecular orbitals. The researchers will use external perturbations, i.e. laser pulses, to shift electron density on a time scale faster than the period of the ground state Pt-Pt stretch, and follow with systematic investigations of dipole correlations by transient optical anisotropy, electronic couplings by two-dimensional electronic spectroscopy. They will further investigate the implications of these coherent motions in chemical and photochemical processes.

在这个由化学部化学结构、动力学和机理项目资助的项目中，西北大学的Lin Chen教授和北卡罗来纳州立大学的Felix Castellano教授正在开发光谱和合成方法来研究过渡金属配合物（TMC）中的多个金属中心如何发挥作用合作将太阳光的能量转化并积累为多个电子势，最终驱动催化反应以产生燃料。拟议的研究符合 NSF 的战略和绩效目标，以改变前沿并为社会创新。 通过拟议的研究获得的知识可能会对化学科学产生变革，并将极大地提高我们合理设计用于催化、光电子和能源可持续性的化学材料/设备的能力。 该研究活动让大学研究生使用先进的激光设备进行表征，使用先进的化学实验室设施进行材料合成，为他们提供了发展多学科专业知识的独特训练场。 下一代 STEM 劳动力迫切需要此类培训，以探索化学科学前沿并保持美国在知识前沿的全球竞争力。拟议的研究/教育活动与针对年轻科学家的公共宣传和指导相结合，包括通过合作培训、暑期学校和以教育为重点的研讨会，包括大学内外的本科生（特别是女性、少数族裔和代表性不足的当地大学生）。这项工作旨在通过设计结构因素来控制电子水平上的材料过程，以影响相干电子和原子运动时间尺度上的分子内电子相互作用和系统浴相互作用。将研究实现多电子转换的机制细节通过新开发的二维电子光谱（2DES）和光学各向异性光谱应用于新的分子结构。 拟议的工作旨在了解多金属中心TMC之间的固有电子耦合及其对光化学反应的影响。 这项工作将通过系统地改变结构因素（例如铂间距离以及配体的空间位阻/能量/尺寸/共轭）来设计一系列二铂配合物中的内在相干运动，从而导致分子轨道的能级。 研究人员将使用外部扰动，即激光脉冲，在比基态 Pt-Pt 拉伸周期更快的时间尺度上移动电子密度，并通过瞬态光学各向异性、电子耦合和瞬态光学各向异性对偶极子相关性进行系统研究。三维电子能谱。 他们将进一步研究这些相干运动在化学和光化学过程中的影响。