Towards a Series of Design Rules for Homogeneous Catalysis: Synergy Between Experiment and Theory

尽管目前能源供应萎缩，对工业环境的影响越来越大，但对在强制条件下制造的产品的需求继续上升(例如，高温、高压)，通常在有毒溶剂的存在下。工业界不断地寻找新的方法来降低生产成本和环境影响。由于现有溶液之间缺乏可转换性，每一类反应都需要重新开始。高效催化剂的合理设计和优化提供了一种解决方案；它也是分子科学中的终极挑战之一，特别是对于均相体系。催化对工业和环境的影响最大，除了减少污染和提高现有工艺的能源效率外，它还开辟了前所未有的方法来创造新的键和化合物。有人提议启动一条新的研究路线，通过实验和理论来建立表征均相交叉偶联催化剂的中心方法学，并增加其“设计规则”。焦点涉及两种不同的交叉耦合机制的理论描述。随后将与合作者一起进行波函数和电子结构分析。对于选定的含镍和钯的体系，将研究所需的产物(交叉偶合)和主要副产物(由β-氢化物消除引起)的形成。将合成催化剂样品以及络合物及其变体，并由项目合作者对其反应性进行表征。结果将有助于候选人同时开拓理论设计的中子谱(NS)实验，以量化取代基烷基动力学及其与催化剂柔性、底物配位和催化中心电子结构的耦合。EPSRC奖将有助于候选人对交叉耦合催化剂的合理优化和设计做出贡献，并扩大NS的应用。该项目将有助于在现有均相催化剂的理论和光谱表征以及新型催化剂的设计方面确立世界权威候选人的地位。这是一个要求很高的项目，其目标是促进高活性交叉偶联催化剂的合理设计，事先使用计算。因此，在分子水平上对配体和金属中心的空间和电子性质有一个基本的了解是必要的。由于大多数有机反应是在溶剂中进行的，而不是在真空或静态介电场中进行的，因此开发一种准确的方法来考虑溶剂的影响是至关重要的(无论多么具有挑战性！)由于候选人已经在这一领域与人合著了几本影响很大的出版物，这个项目将专注于在存在可靠的显式溶剂模型的情况下实现催化反应。上述研究计划的发现将引起更广泛的物理、理论、合成和工业社区的广泛兴趣，正如ISI Web of Science Search最近的宣传和2009年9月刊C&E News中强调的候选人自己的联合通讯工作所证明的那样。

Despite currently shrinking energy supplies and growing industrial environmental impact, demand continues to rise for products manufactured under forcing conditions (eg. high temperature, pressure), often in the presence of toxic solvents. Industry is continually searching for novel means to reducing production expense and environmental impact. The lack of transferability between existing solutions entails starting anew for each class of reactions. Rational design and optimisation of efficient catalysts presents a solution; it also represents one of the ultimate challenges in the molecular sciences, particularly for homogeneous systems. Catalysis has the highest industrial and environmental impact, opening up never-before-possible ways of creating new bonds and compounds besides imparting pollution reduction and energy efficiency to existing processes.A proposal is made to initiate a novel research line to establishing a central methodology towards characterising homogeneous cross-coupling catalysts, by experiment and theory, towards adding to a growing body of 'design rules' thereof. Focus involves the theoretical characterisation of 2 differing cross-coupling mechanisms. Subsequent wavefunction and electronic structure analyses will be carried-out jointly with collaborators. Both the desired product (cross-coupling) and main side-product (arising from beta-hydride elimination) formations will be studied, for selected Ni and Pd-containing systems. Catalyst samples as well as complexes and variations thereof will be synthesised and their reactivities characterised by project collaborators. Results will aid the candidates concurrent pioneering of theory-designed neutron spectroscopy (NS) experiments to quantify substituent alkyl-group dynamics and their coupling to catalyst flexibility, substrate coordination and electronic structure at the catalytic centre.An EPSRC award would be strategic in helping the candidate contribute to the rational optimisation and design of cross-coupling catalysts and to extend the application of NS. The project would be instrumental in establishing the candidate as a world authority in the theoretical and spectroscopic characterisation of existing homogeneous catalysts and design of novel catalysts.This is a demanding project with the objective of advancing the rational design of highly active cross-coupling catalysts, apriori using computation. Therefore, a fundamental understanding at the molecular level of the steric and electronic nature of the ligand and metal centre is essential. Since most organic reactions take place in solvent and not in a vacuum or a static dielectric field, it is pivotal (no matter how challenging!), to develop an accurate method for including the effect of solvent. As the candidate has already co-authored several high-impact publications in this area, this project will focus on the realisation of catalysed reactions in the presence of a reliable explicit solvent model. The findings of the above program of research will be of vast interest to the wider physical, theoretical, synthetic and industrial communities, as witnessed by the recent publicity detailed from ISI Web of Science searches and the candidate's own co-corresponded work highlighted in the September 2009 issue of C&E News.