Thiolate-Protected Au25 Superatoms as Building Blocks: Dimers and Crystals
journal contributionposted on 30.09.2010, 00:00 by Jaakko Akola, Katarzyna A. Kacprzak, Olga Lopez-Acevedo, Michael Walter, Henrik Grönbeck, Hannu Häkkinen
A particularly stable thiolate-protected gold nanocluster, Au25(SR)18, was structurally characterized from X-ray crystallography in 2008, and concomitantly its electronic and optical properties were analyzed via density functional theory. The robust geometry and a well-understood electronic structure of this cluster motivate explorations of properties of extended systems made out of Au25(SR)18 building blocks. As a first step in this direction, we analyze here structural, vibrational, electronic, and optical properties of the Au25 cluster anion as it was observed in the crystalline environment and predict properties of cluster dimers, where the Au25 units are linked together via an aromatic dithiolate linker. We show that properties of each Au25 unit of the dimer can be quite independently modified from the other by doping with a nonmagnetic (Pd) or magnetic (Mn) metal atom. We anticipate that material systems with interesting properties could be made from these building blocks, provided that a suitable chemistry for their controlled linking can be found.