title: Anomalous diamagnetic susceptibility in 13-atom platinum nanocluster superatoms.
abstract: We are used to being able to predict diamagnetic susceptibilities χD to a good approximation in atomic increments since there is normally little dependence on the chemical environment. Surprisingly, we find from SQUID magnetization measurements that the χD per Pt atom of zeolite-supported Pt13 nanoclusters exceeds that of Pt(2+) ions by a factor of 37-50. The observation verifies an earlier theoretical prediction. The phenomenon can be understood nearly quantitatively on the basis of a simple expression for diamagnetic susceptibility and the superatom nature of the 13-atom near-spherical cluster. The two main contributions come from ring currents in the delocalized hydride shell and from cluster molecular orbitals hosting the Pt 5d and Pt 6s electrons.
authors.affiliation: Institute of Physical Chemistry, University of Stuttgart, 70563 Stuttgart (Germany); University of Pretoria, 0002 Pretoria (Republic of South Africa). E.Roduner@ipc.uni-stuttgart.de.
authors.forename: Emil
authors.initials: E
authors.lastname: Roduner
authors.forename: Christopher
authors.initials: C
authors.lastname: Jensen
authors.forename: Joris
authors.initials: J
authors.lastname: van Slageren
authors.forename: Rainer A
authors.initials: RA
authors.lastname: Rakoczy
authors.forename: Oliver
authors.initials: O
authors.lastname: Larlus
authors.forename: Michael
authors.initials: M
authors.lastname: Hunger
keywords: EPR spectroscopy; diamagnetism; platinum clusters; superatoms