Gold-thiolate core-in-cage cluster Au25(SCH3)18 shows localized spins in charged states

Unrestricted density functional calculations have revealed spin-polarized electronic structures of a charged gold-thiolate cluster [Au25(SCH3)18]n with a core-in-cage structure [Au7–(AuSCH3)18]. The charged states vary from 3− to 3+. The optimized structures in the different charged states show only minor geometrical changes. For n = 2−, three parallel spins are found to be localized at the Au7 core cluster, and hence high magnetic anisotropy is expected because the core cluster has a nearly planar geometry. These features are ascribed to a unique structure of the present gold-thiolate cluster, Au25(SCH3)18, that the Au7 core cluster is protected by the robust (AuSCH3)18 cage.