鼓型CoB16-团簇电子结构的探索：罕见的Co(-1)氧化态

本文发现CoB₁₆^-团簇由两个对称、上下错位相连的B₈环和位于中心的Co原子组成，它代表了金属掺杂硼纳米管结构的潜在雏形，这一发现为设计一维金属-硼纳米结构提供了机会. 本文报道了CoB₁₆^-新的实验光电子能谱，并采用量子化学方法对其电子结构和化学成键特性进行了详细的电子结构分析，为进一步了解金属掺杂硼纳米管结构的化学键和稳定性提供了深入的见解. 有趣的是，发现该类体系的中心Co原子具有异常低的氧化态，即负一价钴(-1). 因此中性CoB₁₆分子可以被视为配体到金属的电荷转移化合物(Co^-@BB₁₆⁺). 研究表明，掺杂金属和硼管之间的相互作用来源于共价和静电作用的相互协调，硼元素低的电负性使得硼团簇成为形成各种低价态化合物的重要化学配体.

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

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 B₈ 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^-@BB₁₆⁺), suggesting both covalent and electrostatic interactions between the dopant and the boron drum.