Electronic structure of open-shell Zintl clusters

Thesis

This thesis presents a theoretical investigation of clusters composed of transition metals and main-group elements, namely Zintl clusters. The studied systems can be broadly categorised into two types: (i) endohedral clusters with core-shell architectures, and (ii) clusters in which transition metal centres are coordinated directly to inorganic or organic ligands. All clusters discussed in this work have been synthesised and structurally characterised by single-crystal X-ray diffraction. However, limited experimental data beyond crystallographic analysis underscore the importance of gaining a deeper understanding of their electronic structures through theoretical approaches. The central strategy of this thesis is to compare the target clusters with either experimentally known or hypothetical reference systems, allowing us to elucidate differences in geometry and electronic structure. Particular emphasis is placed on metal-metal bonding, which is analysed using Density Functional Theory, and where necessary, multi-configurational methods such as Density Matrix Renormalisation Group are employed to account for strong correlation effects – especially in high-spin systems or in the presence of spin contamination when using DFT. In endohedral clusters, metal-ligand interactions are explored in detail, with special attention to the role of back-bonding and its influence on stabilising intermediate cage geometries. In Fe-pnictogen systems, correlations between metal and ligand geometries are examined, originating from electron density redistribution within the clusters. Collectively, this work highlights how theoretical methods can provide essential insights into the bonding and electronic properties of Zintl chemistry.

Authors: Li, Z

• DOI: 10.5287/ora-mzpqrnp4m
• Type of award: DPhil
• Level of award: Doctoral
• Awarding institution: University of Oxford
• Language: English
• Subjects: Inorganic Chemistry