title: Hollow cages versus space-filling structures for medium-sized gold clusters: the spherical aromaticity of the Au50 cage.
abstract: Candidates for the lowest energy structures of medium-sized Au(n), n = 32, 38, 44, 50, and 56, clusters were evaluated using gradient-corrected DFT computations. Both hollow cage and space-filling conformations were considered. The cages were constructed using fullerene-based templates. The space-filling structures were generated by employing a genetic algorithm. We have found that the space-filling isomers were lower in energy except for two notable cases. Like Au(32) [Johansson, M. P.; Sundholm, D.; Vaara, J. Angew. Chem. Int. Ed. 2004, 43, 2678], a hollow cage configuration of Au(50) is more stable than its alternative space-filling isomeric forms. The unusual stabilities of the cage Au(32) and Au(50) can be attributed to spherical aromaticity; both exhibit large negative nucleus-independent chemical shifts and exceptionally large HOMO-LUMO gaps.
authors.affiliation: Chemistry Division, Argonne National Laboratory, Argonne, IL 60439, USA.
authors.forename: Jinlan
authors.initials: J
authors.lastname: Wang
authors.forename: Julius
authors.initials: J
authors.lastname: Jellinek
authors.forename: Jijun
authors.initials: J
authors.lastname: Zhao
authors.forename: Zhongfang
authors.initials: Z
authors.lastname: Chen
authors.forename: R Bruce
authors.initials: RB
authors.lastname: King
authors.forename: Paul von Ragué
authors.initials: Pv
authors.lastname: Schleyer