| Popis: |
Boron, the fifth element in the period table, exhibits diverse bonding patterns and interesting structures due to its electron deficiency. Unlike its neighbor carbon, closed-packed boron sheet with graphene-like honeycomb lattice is unstable so that planar boron clusters usually have interior vacancies and corrugated appearance. Delocalized multi-center bonding has an important role to stabilize the 2D structures, giving rise to the concept of σ, π, …multiple aromaticity. The experimental observation of the B36− cluster in 2014 established the viability of boron monolayer which was named as “borophene” by Wang and Li. Recently, studies on planar CoB18− and RhB18− clusters have suggested the possibilities of metal-doped borophenes (metallo-borophenes) with potentially tunable electronic, magnetic and optical properties. In this review, we summarize recent experimental and theoretical advances in 2D pure-boron and metal-doped boron clusters, as well as their implications for borophenes and metalloborophenes as novel new boron materials. |
