| Abstract
| - Extended Hückel and density functional calculations carried out on 128-MVE Cu8(dithiolato)6 edge-bridged cubicclusters indicate that their stability is mainly driven by the chelating effect of the ligands, which provide a stable16-electron configuration to the approximately trigonal planar metal centers. Nevertheless, a weak but significantd10−d10 bonding interaction is present which is rather independent from the dithiolato bite effect. The metalcenters have a nonbonding 4pz vacant AO pointing to the center of the cube available for bonding to an encapsulatedatom. The electronic closed-shell requirement is satisfied for the 136-MVE and 140-MVE counts, respectively,when a main-group atom or a transition-metal atom is incorporated in the middle of the cube. The bonding withinthese dithiolato compounds is compared to other edge-bridged M8 cubic clusters. In particular, it is shown thatclusters of higher nuclearity but containing an M8 cubic core are related to the dithiolato species. Indeed, theirouter metal atoms can be considered as belonging to the ligand shell, interacting with the M8 cube in a waysimilar to the dithiolato ligands in the Cu8 species.
- A bonding analysis of Cu8(dithiolato)6 cubic clusters is provided, which allows one to understand their structure and stability. Centered clusters and other species of various nuclearity containing an edge-bridged M8 cube are also investigated.
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