Sn122-: Stannaspherene

PRES 28

Li-Feng Cui, lifeng.cui@pnl.gov1, Xin Huang, xin.huang@pnl.gov1, Lei-Ming Wang, leiming.wang@pnl.gov1, Dmitry Yu. Zubarev, dzoubarev@cc.usu.edu2, Alexander I Boldyrev, boldyrev@cc.usu.edu3, Jun Li, jun.li@pnl.gov4, and Lai-Sheng Wang, ls.wang@pnl.gov1. (1) Department of Physics, Washington State University, 2710 University Drive, Richland, WA 99354, (2) Department of Chemistry and Biochemistry, Utah State University, 0300 Old Main Hill, Logan, UT 84322-0300, (3) Chemistry and Biochemistry, Utah State University, 0300 Old Main Hill, Logan, UT 84322, (4) W. R. Wiley Environmental Molecular Sciences Laboratory, Pacific Northwest National Laboratory, P.O. Box 999, richland, WA 99352
During photoelectron spectroscopy experiments aimed at understanding the semiconductor-to-metal transition in tin clusters, the spectrum of Sn12- was observed to be remarkably simple and different from that of Ge12-, suggesting that Sn12- is a unique and highly symmetric cluster. It was found to possess a slightly distorted cage structure with C5v symmetry. However, adding an electron to Sn12- resulted in an Ih-Sn122- cluster, which was synthesized as K+[Sn122-]. The Ih-Sn122- cage is shown to be bonded by four delocalized radial π bonds and nine delocalized on-sphere tangential σ bonds from the 5p orbitals of the Sn atoms, whereas the 5s2 electrons remain largely localized and nonbonding. The bonding pattern in Sn122- is similar to the well-known B12H122- cage. The Sn122- cage, for which a name “stannaspherene” is coined, has a diameter of 6.1 Å, suggesting it can trap a variety of atoms to form endohedral stannaspherenes.