Probing the Electronic Structure of the CoB16-Drum Complex: Unusual Oxidation State of Co-1

摘要

Since the discovery of the first drum-like CoB16-complex,metal-doped drum-like boron nanotubular structures have been investigated with various metal dopants and different tubular size,forming a new class of novel nanostructures.The CoB16-cluster was found to be composed of a central Co atom coordinated by two fused Bs rings in a tubular structure,representing the potential embryo of metal-filled boron nanotubes and providing opportunities to design one-dimensional metal-boron nanostructures.Here we report improved photoelectron spectroscopy and a more in-depth electronic structure analysis of CoB16-,providing further insight into the chemical bonding and stability of the drum-like doped boron tubular structures.Most interestingly,we find that the central Co atom has an unusually low oxidation state of-1 and neutral CoB16 can be viewed as a charge transfer complex (Co-@B16+),suggesting both covalent and electrostatic interactions between the dopant and the boron drum.