Hollow cages versus space-filling structures for medium-sized gold clusters: the spherical aromaticity of the Au50 cage.
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.
Wang
Jinlan
J
Chemistry Division, Argonne National Laboratory, Argonne, IL 60439, USA.
Jellinek
Julius
J
Zhao
Jijun
J
Chen
Zhongfang
Z
King
R Bruce
RB
Schleyer
Paul von Ragué
Pv