LAUSR

Abstract The planar ribbon form is the lowest-energy structure of the neutral and negatively charged B16 clusters, especially planar B162− with ten delocalized π electrons is viewed as an all-boron naphthalene, whereas the doped B16TM− by transition metals unexpectedly exhibit the high coordinated TM-centered tubular structures. We found herein a totally different picture in B16M−/B16TM− (M = Li, Na, K; TM = Ag, Au) doped by s-block metals (being isoelectronic to B162−) relative to the reported B16-based clusters. A new quasi-planar trapezoid structure is predicted to be a global minimum, where B16TM− (TM = Ag, Au) presents chemistry similar to that of hydrogen in its bonding to boron. The chemical bonding and structural integrity of the quasi-planar trapezoid structure is not altered significantly in B16M−, suggesting its stability and viability as a promising building block for boron-assembled nanomaterials.