Metal Complexes of the Carbon Dioxide Dianion

如果从根本上了解还原剂对二氧化碳分子的作用，那么热力学稳定且动力学惰性的底物二氧化碳只能被认为是合成和催化的C1源。本项目涉及二氧化碳双核配合物的合成、结构分析和机理研究，这些二氧化碳是由3和4基团的正电和亲氧金属衍生的。不同电子和空间性质的配体与不同亲电性/亲氧性的早期过渡金属中心结合将产生新的配位模式。特别关注的是几乎未被探索的离子CO22-的配位，它是由双去质子化的二羟基碳C(OH)2衍生而来的，与甲酸的互变异构体相对应。我们假设二氧化碳在金属配位球内的化学还原可能引发进一步的二氧化碳插入和C-C键形成反应。在新的金属配合物与化学还原形式的二氧化碳将被合成后，机理研究将进行。我们期待金属介导的二氧化碳活化的新可能性，超越加氢成甲酸，甲醇或甲烷，并将导致更大的合成基石Cn bbb101。

The thermodynamically stable and kinetically inert substrate carbon dioxide can only be considered as a C1 source for synthesis and catalysis, if the effect of reducing agents on this molecule are fundamentally understood. This project deals with the synthesis, structural analysis and mechanistic studies of dinuclear complexes of carbon dioxide, which are derived from electropositive and oxophilic metals of groups 3 and 4. Combining ligands of varied electronic and steric properties with early transition metal centers of different electrophilicity/oxophilicity shall lead to new coordination modes. A particular focus is on the coordination of the nearly unexplored dianion CO22-, which is formally derived from doubly deprotonated dihydroxycarbene C(OH)2 and corresponds to the tautomer of formic acid. We assume that the chemical reduction of carbon dioxide within the coordination sphere of a metal may trigger further CO2 insertion and C-C bond forming reactions. After the new metal complexes with a chemically reduced form of CO2 will be synthesized, mechanistic studies will be performed. We expect new possibilities for metal mediated activation of carbon dioxide that goes beyond the hydrogenation to formic acid, methanol, or methane and shall lead to larger building blocks Cn>1 for synthesis.