Cohesion in Coordination Chemistry

这项合作工作解决了协调和有机金属化学的凝聚力的问题，主要是非共价相互作用（NCIS）的作用，在涉及d-区过渡金属的反应中，分子内的伦敦分散力被怀疑是必不可少的稳定的实验和理论研究的共同努力。多年来，NCIs在配位化学中一直被忽视。最近的研究表明，占这些相互作用的影响是必不可少的，以产生一个物理上正确的评估的重要性，金属配体的伴随缔合能量和中间体的相对稳定性。预计在涉及配体-金属键形成的配位反应中，如在催化过程中遇到的，远程有机片段通过显著的分散项对配体-金属缔合能做出贡献。色散校正密度泛函理论（DFT-D3）的最新进展使得研究气体、溶液和固体中涉及大的（100-200个原子）过渡金属络合物的反应成为可能。这构成了一个新的框架，进一步提高反应动力学曲线，区域，化学和立体选择性的一般理解。然而，仍然存在两个隐患。第一个是缺乏全面准确的配体-金属结合的热力学数据，这些数据可以作为评估量子化学（QC）方法的标准。第二，密切结合到前者的改进，是植根于已知的限制连续溶剂化模型。该项目提出了一种解决方案，该解决方案基于通过等温滴定量热法对基元反应进行的研究，该技术可以精确测量低至1 kcal/mol的反应速率。它的目标是研究已知的过渡金属反应。ITC获得的热力学信息将面临基于DFT-D3和耦合簇型波函数理论（WFT）的理论方法对相同热化学的评估，以阐述新的基准参考。这种理论与实验对抗的关键目标是在系统的基础上评估当代QC方法的性能，特别是对于溶液中发生的反应。进一步的研究将集中在联合实验/理论评估的性质和强度的非共价相互作用参与所谓的hemichelation的配体相互作用与hemichelates的热化学的系统调查。进一步的研究将针对合成具有不同电子不饱和金属中心的半螯合物的新情况。

This collaborative work addresses the issues of cohesion in coordination and organometallic chemistry fostered by a mutual effort in experimental and theoretical investigations of the role of predominantly non-covalent interactions (NCIs) in reactions involving d-block transition metals where intramolecular London dispersion forces are suspected to be essential to their stabilization. For years, NCIs have been overlooked in coordination chemistry. Recent research shows that accounting for the effect of these interactions was essential to produce a physically correct assessment of the importance of metals ligand retinue on association energies and on relative stabilities of intermediates. It is expected that in coordination reactions involving ligand-metal bond formation, as encountered in catalytic processes, remote organic fragments contribute to the ligand-metal association energy by way of a significant dispersion term. Recent advances in dispersion-corrected DFT (namely DFT-D3) renders the investigation of reactions involving large (100-200 atoms) transition metal complexes possible in the gas, solution, and the solid state. This constitutes a new framework for improving further the general understanding of reaction kinetic profiles, regio, chemo and stereoselectivities. However, two pitfalls remain. The first one is the lack of comprehensive accurate thermodynamic data for ligand-metal binding that could serve as standard for the evaluation of quantum chemical (QC) methods. The second, intimately bound to the improvement of the former, is rooted in the known limitations of continuum-based solvation models. The project proposes a solution based on the investigation of elementary reactions by means of isotherm titration calorimetry, a technique that allows the accurate measure of enthalpies of reactions as low as 1 kcal/mol. It targets the study of known transition metal reactions. Acquisition of thermodynamic information by ITC is to be confronted to the assessment of the same thermochemistry by theoretical methods based on DFT-D3 and coupled-cluster type wave function theory (WFT) in order to elaborate a new benchmark reference. The critical goal of this confrontation of theory with experiment is to evaluate on a systematic basis the performance of contemporary QC methods particularly for reactions occurring in solution. Further research will be focused on the joint experimental/theoretical assessment of the nature and strength of non-covalent interactions involved in so-called hemichelation by a systematic investigation of the thermochemistry of ligand interaction with hemichelates. Further research will target the synthesis of new cases of hemichelates bearing different electron-unsaturated metal centers.