Elucidation of Reaction Mechanism with the Unified Reaction Valley Approach: Part III Homogeneous Catalysis and Beyond

有了这个奖项，化学结构，动力学和机制（CSDM-B）和计算和数据支持的科学与工程（CDS E）计划正在支持南卫理公会大学的Elfi Kraka和Dieter Cremer教授，为下一代化学催化剂结合均相和酶催化的特点得出一般设计原则。Cremer和Kraka的统一反应谷方法（URVA）旨在作为一种量子化学工具，在比目前容易实现的更高水平上研究催化反应的机制。 URVA的作用就像一个“高分辨率相机”连接到反应复合物，能够揭示振动和反应复合物的电子结构变化之间的相互作用。它记录了当反应复合物沿着反应侧的能量谷向上到达能量通过点，然后向下通过出口谷到达产物时的所有事件。通过分析反应路径的方向和曲率而不是反应复合物本身的特征来区分重要和不太重要的事件。催化反应和非催化反应之间的基本区别可以用这种方法来确定，但人造催化剂的局限性也是显而易见的。 酶是为应对严峻的生存压力而开发的经过良好调整的催化剂。鉴于在许多酶中看到的显着的催化能力，主要的重点将是URVA方法的扩展和应用，以确定其主要优点。对过渡金属、非过渡金属、无金属和（人工）酶催化反应的机理进行了系统的分析和比较。一个从头催化剂设计的战略是开发，其中，包括化学和生物催化方面，可以作为一个孵化器，加强跨学科的努力，以产生目标特定的催化剂。 研究的所有反应（包括反应影片）的数据将被收集在CATCO反应库中，该库将增加到500多个反应。这个库将提供给化学界的研究，教学和学生培训。在过去的两年中，URVA已被证明是一个独特的工具，为150多个均相催化反应的机理研究。除了遵循键断裂和形成的化学过程之外，URVA还使用了一种大大改进的算法，用于跟踪反应谷到货车范德华区域，以高细节水平监测化学过程前后。用内坐标或曲线坐标分量分析了反应谷的方向和曲率，并将其与电子结构的变化直接联系起来。URVA的其他重要工具是局部振动模式分析，电荷转移和电荷极化分析以及化学反应的反应阶段的介绍。 方法开发将包括i）URVA方法的设计和编程，用于隐式或显式包含溶剂效应，ii）用于调查“相对论”系统的2组分相对论方法，以及iii）用于描述酶环境中化学反应的新QM/MM方法。

With this award, the Chemical Structure, Dynamics and Mechanism (CSDM-B) and Computational and Data-Enabled Science and Engineering (CDS&E) programs are supporting Professors Elfi Kraka and Dieter Cremer at Southern Methodist University to derive a general design principle for the next generation of chemical catalysts combining features of homogenous and enzyme catalysis. The unified reaction valley approach (URVA) of Cremer and Kraka aims to serve as a quantum chemical tool to study the mechanism of catalyzed reactions at a greater level of than is currently easily achieved. URVA acts like a "high-resolution-camera" attached to the reaction complex, being able to reveal the interplay between vibrations and the electronic structure changes of the reaction complex. It records all events when the reaction complex follows the energy valley on the reaction side up to the energy pass point and then down through the exit valley to the products. Important and less important events are differentiated by analyzing direction and curvature of the reaction path rather than features of the reaction complex itself. Basic differences between and catalyzed and non-catalyzed reactions can be determined in this way, but also the limitations of man-made catalysts are apparent. Enzymes are the well-tuned catalysts developed in response to stringent survival pressures. Given the remarkable catalytic power seen in many enzymes, the major focus will be on the extension and application of the URVA methodology to enzyme catalysis to determine its major advantages. The mechanism of transition metal, non-transition metal or metal-free- and (artificial) enzyme-catalyzed reactions will be systematically analyzed and compared. A strategy for de novo catalyst design is to be developed, which, by including aspects of both chemo- and bio-catalysis, can serve as an incubator for enhanced interdisciplinary efforts to generate target-specific catalysts. The data of all reactions investigated (including reaction movies) will be collected in the CATCO reaction library, which will increase to more than 500 reactions. This library will be available to the chemical community for research, teaching, and student training.During the past two years, URVA has proven to be a unique tool for the mechanistic study of more than 150 homogenous catalysis reactions. In addition to following the chemical processes of bond breaking and forming, URVA uses a substantially improved algorithm for following the reaction valley far out into the van der Waals region to monitor pre- and post-chemical processes in a high level of detail. The direction and curvature of the reaction valley are analyzed in terms of internal coordinate or curvilinear coordinate components and then directly related to electronic structure changes. Other essential tools of URVA are the local vibrational mode analysis, the charge transfer and charge polarization analysis as well as the presentation of the chemical reaction in terms of reaction phases. Method development will include the design and programming of i) URVA methodologies for an implicit or explicit inclusion of solvent effects, ii) 2-component relativistic methods for the investigation of "relativistic" systems, and iii) new QM/MM methodologies for the description of chemical reactions in an enzymatic environment.