Synthesis and characterization of metalloid gold clusters

• Applicant: Professor Dr. Andreas Schnepf
• Subject Area: Inorganic Molecular Chemistry - Synthesis and Characterisation
• Term: from 2019 to 2023
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 434242866

The present follow-up application is based on the results of a DFG grant, in which we have already been able to synthesize and characterize many new metalloid cluster compounds of gold. Furthermore, we were able to gain important insights into the cooperative properties of the clusters in the solid state, which on the one hand increase the electrical conductivity by two orders of magnitude and have on the other hand an impact on the optical properties. Furthermore, we were able to establish several new groups of metalloid cluster compounds of gold in another project. These investigations are now to be continued, with an extension to metalloid silver clusters or intermetalloid gold/silver clusters being planned in the current application. Here we can fall back on the already established synthesis of Ag64(PnBu3)16Cl6. The stability of this cluster should be increased by substitution of the halogen substituents and by the incorporation of gold atoms during synthesis. Increasing the thermal and photochemical stability is essential for further applications of this cluster, which is obtained in excellent crystalline yields of about 80%. The synthesis of metalloid silver clusters is also to be further expanded, with initial investigations showing the potential of our synthetic approach, in which significantly larger metalloid silver clusters with up to 164 ?? silver atoms are accessible. These clusters are like Ag64(PnBu3)16Cl6 in terms of both sensitivity and the unusual non-spherical structure, so that a new class of metalloid silver clusters can be established here. In the field of metalloid gold clusters, our synthesis route is to be extended to thiolate-stabilized clusters. A first example shows that here too we can open-up access to a new class of metalloid cluster compounds in which no staple motifs are present and where new arrangements of the gold atoms are realized in the cluster core. The question what influence the staple motifs on the chemical and physical properties of a metalloid gold cluster have can then also be addressed and whether the gold atoms in the staple motif, which are not included in the cluster core can be used for applications, e.g. in the field of catalysis. These investigations are supported by quantum chemical calculations, some of which are carried out in collaboration with Prof. Clayborne at George Mason University, Fairfax/USA. Based on these results, influencing parameters can be better identified, which makes it possible to plan synthesis more easily, which also makes the application-related relevance of the planned investigations clear.

• DFG Programme: Research Grants