Pentadienyl ligands for the stabilization of unusual oxidation states and as directing ligands in homogenous catalysis

戊二烯配体是优良的δ受体，因此非常适合于金属络合物在低氧化态下的稳定。这一性质将被用来制备早、晚过渡金属和稀土金属的手性和非手性戊二烯配合物。除了分子物种的研究外，我们还打算探索这些分子化合物在“表面金属有机化学”(SOMC)中的潜力。下一步将探索接枝材料和分子模型络合物的合成和催化潜力，如插入反应和小分子(如CO、CO2、P4、N2O、N2、CH-键)的活化和官能化。我们已经证实，PdL-配体也可以作为双阴离子和三阴离子的配体体系，这是当试图在不寻常的氧化状态下访问第4族金属和稀土络合物时形成的。关于这些观察，我们寻求更详细的了解潜在的反应机理，但也探索这些物种对小分子的反应性。我们的研究重点是探索结构-反应关系，这些研究的结果将指导这些体系在催化和材料合成中的潜在应用。

Pentadienyl (Pdl)- ligands are excellent δ-acceptors and therefore well-suited for the stabilization of metal complexes in low oxidation states. This property will be used to prepare chiral and achiral pentadienyl complexes of the early and late transition metals and the rare-earth metals. Besides investigations of the molecular species we also intend to explore the potential of these molecular compounds in “surface organometallic chemistry” (SOMC). In the next step the grafted materials and molecular model complexes will be probed for their synthetic and catalytic potential e.g. towards insertion reactions and the activation and functionalization of small molecules (such as CO, CO2, P4, N2O, N2, CH-bonds). We have already established that Pdl-ligands may also act as di- and trianionic ligand systems, which are formed when attempts were made to access group 4 metal and lanthanide complexes in unusual oxidation states. With respect to these observations we seek a more detailed understanding on the underlying reaction mechanism, but also to probe the reactivity of these species towards small molecules. Major emphasis of our research program is the exploration of the structure-reactivity relationship and the results derived from these studies will guide the potential application of these systems in catalysis and material synthesis.