Chapter 2: Rational Design of Mixed Nanoclusters: Metal Shells Supported and Shaped by Molecular Cores

This work considers a variety of core–shell systems with atom to small to larger molecule inside cluster cages of a few different metals. Evolution of the system structure and some related properties are followed with changing the shell size and material, and the core–shell interaction from covalent to noncovalent, for the latter case with and without a charge transfer between the core and the shell. Different inserted “dopands” are shown to reshape the host cage slightly or considerably, and the stability of the resulting species is found to be sensitive to the specific core+shell combination (from unstable to metastable to stable). Together with a rich variation of the electronic properties (charge distributions, excitation and ionisation energies, electron affinities) upon such a ‘doping’, this can enable a flexible design of systems with desirable geometric and physical-chemical parameters for numerous potential applications. Some other specific aspects discussed include dis- and similarities of metallocarbon and hydrocarbon species, separation of the system property alterations due to change of the cage shape alone and due to further core–shell bonding, hypercoordination of the core atoms, as well as mutual influence of the core and the shell, possible shell-induced and -aligned chemical reactivity of the core.