Molecular metal siloxides as models for functional units of oxidic frameworks and surfaces

• Applicant: Professor Dr. Christian Limberg
• Subject Area: Inorganic Molecular Chemistry - Synthesis and Characterisation
• Term: since 2020
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 439279302

The target of this project is the synthesis and investigation of molecular compounds, which can mimic structural units occurring on the surfaces of oxides with high abundance and application relevance; concretely, aluminium oxides/hydroxides, iron oxides and aluminosilicates are in the focus, in case of the aluminosilicates special attention is on metal-modified variants. The siloxide ligands used for the construction of the molecules will suit the trapping and stabilization of oxide/hydroxide aggregates as well as the simulation of silicate environments. The investigation of such compounds on the one hand is supposed to contribute to a fundamental, atomic-scale understanding of the behavior of corresponding units, for instance in contact with water. Water is ubiquitous during the synthesis, dissolution and application of the mentioned materials and the elucidation of the corresponding mechanisms is of basic significance. On the other hand it is envisaged to make functional units, which exhibit interesting reactivities as part of silicate materials (in particular metal-modified zeolites), accessible and utilizable for chemical investigations and applications in solution. Subsequent to the development of corresponding surface-inspired molecules the potential to activate dioxygen or O-atom transfer reagents will be tested to finally achieve the oxyfunctionalisation of hydrocarbons; accordingly, a further goal is the development of novel functional molecules. In case of zeolite-like reactivities the application of the methods inherent to molecular chemistry can also reveal mechanistic information that advances the understanding of reactivities observed in case of the solid-state materials. According to the selection of materials chosen as guides for molecular synthesis the project will deal with aluminium, copper, nickel, and iron siloxides.

• DFG Programme: Research Grants