Reaction Tomography - Atomically Resolved Imaging of Chemical Transformations with Molecular Functionalized SPM Tips

在化学系化学测量和成像项目的支持下，加州大学伯克利分校的Fischer教授正在开发原子分辨成像技术，该技术增强了可用于成像、操作和光谱表征表面分子结构的反应性和自组装的分析工具。该研究计划克服了原子分辨率扫描探针技术应用中面临的挑战，使这些技术更容易为研究人员所用，并且更能够回答有关分子系统的化学组成，电子结构和反应性的重要科学问题。开发的工具和技术不仅能够以单原子分辨率识别未知化合物，而且对需要精确了解原子尺度过程的所有纳米科学领域产生影响。这包括在能源研究、分子尺度电子学、分子识别和传感器技术等领域开发有益于社会的新应用。跨学科的科学是在这个项目的核心是介绍给各级学生，从K-12，跨本科到研究生水平通过综合研究和教育组件。从加州州立大学东湾招募的本科生作为合成有机化学暑期培训计划的一部分，有助于建立一个公众可访问的图书馆，作为K-12和本科教育工作者的资源，吸附分子系统的原子分辨图像。 该研究项目的目标是开发扫描探针显微镜（SPM）技术，能够以比以前更高的空间分辨率和元素特异性分辨单个原子和分子键合构型。一类新的分子探针尖端是来自多脚和螯合配体，选择性地结合到低协调的过渡金属内衬的电蚀刻SPM尖端的顶点。这些化学工程探针尖端具有电子和振动可调的顶点配置，能够诱导与表面上的分子吸附物的元素特异性共价或非共价相互作用。该项目的重点是克服单分子SPM技术目前面临的三个重大挑战？在非平面分子结构中实现原子分辨率，实现原子分辨的元素组成，以及实现键强度及其顺序的无失真表征。本文开发的SPM技术解决了单分子成像前沿的关键挑战，为发现和阐明表面促进反应机制铺平了道路，该奖项反映了NSF的法定使命，并通过利用基金会的知识价值和更广泛的影响进行评估，被认为值得支持审查标准。

With support from the Chemical Measurement and Imaging Program in the Division of Chemistry, Professor Fischer at the University of California, Berkeley, is developing atomically resolved imaging techniques that enhance the analytical tools available to image, manipulate, and spectroscopically characterize the reactivity and self-assembly of molecular structures on surfaces. This research program overcomes challenges faced in the application of atomic-resolution scanned probe techniques, and makes these techniques both more accessible to researchers and more capable of answering significant scientific questions regarding the chemical composition, electronic structure, and reactivity of molecular systems. The tools and techniques developed are not only be able to identify unknown compounds with single-atom resolution, but have an impact on all nanoscience areas that require precise knowledge of atomic-scale processes. This includes the development of new applications that benefit society in the areas of energy research, molecular-scale electronics, molecular recognition, and sensor technology. The interdisciplinary science that lies at the core of this project is introduced to students at all levels, from K-12, across the undergraduate to the graduate level via integrated research and educational components. Undergraduate students recruited from California State University East Bay as part of a summer training program in synthetic organic chemistry contribute to the establishment of a publicly accessible library for atomically-resolved images of adsorbed molecular systems that serve as a resource for K-12 and undergraduate educators. The goal of this research project is to develop scanned probe microscopy (SPM) techniques capable of resolving individual atoms and molecular bonding configurations with higher spatial resolution and elemental specificity than previously possible. A new class of molecular probe tips is derived from multipodand chelating ligands that selectively bind to low-coordinated transition metals lining the apex of electrically etched SPM tips. These chemically engineered probe tips feature electronically and vibrationally tunable apex configurations capable of inducing element specific covalent or non-covalent interactions with molecular adsorbates on surfaces. The project focuses on overcoming three significant challenges currently faced by single-molecule SPM techniques ? achieving atomic resolution in non-planar molecular structures, achieving atomically-resolved elemental composition, and achieving distortion-free characterization of bond strengths and their order. The SPM techniques developed herein address key challenges at the forefront of single molecule imaging, pave the way for the discovery and elucidation of surface facilitated reaction mechanisms, and provide an unprecedented detailed insight into the most elemental steps of common chemical transformations.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.