Ribbon Aromaticity of Double-Chain BCH Clusters ( n = 2-9): A First Principle Study.

The double-chain boron ribbon should be taken as an element geometric unit for the construction of boron fullerenes and sheets. In this work, a series of BCH clusters ( n = 2-9) were extensively investigated using the density functional theory and the coupled cluster method. The most stable structures of BCH are planar double-chain nanoribbon with lengths from 3.9 to 15.0 Å. The adaptive natural density partitioning analyses show that there exist conjugated multi-center π bonds along the nanoribbons. The two-dimensional contour pictures of the nucleus-independent chemical shifts reveal that BCH clusters have ribbon aromaticity that fluctuates along the ribbons. This finding will provide new insights on the boron fullerenes and the two-dimensional boron sheets. [ABSTRACT FROM AUTHOR]