Aromatic trails: persistence and interplay between linked spherical aromatic dicarboranes in dimer to hexamer linear arrays

Abstract

The consecutive crack-linking between well-defined building blocks is a plausible strategy for developing molecularly designed materials. Here, we evaluated the resulting behavior of dimer to hexamer linear arrays formed by linking spherical aromatic para-[C₂B₁₀H₁₀] clusters (1) as relevant motifs toward understanding the characteristics of extended linear materials. Our results exhibited the persistence of spherical aromatic properties from the parent building block as isolated spherical aromatic states within the overall structure. Under different orientations of the applied field, the multiple shielding cones enabled at each linked cluster evolved from a perfectly parallel disposition to an enhanced overlap upon rotation. In addition, large values of NICS isosurfaces served to locate the independent spherical aromatic states, whereas the use of anisotropy (NICS_aniso) recovered the resulting isotropic regions at such states within the overall linear structure. Such behavior is expected to be envisaged in extended linear arrays and non-covalently interacting scenarios, such as self-assembled monolayers. Our results encourage further quests for understanding the interplay between different linked aromatic states, aiming to understand and unravel the overall behavior of extended architectures designed by connecting aromatic building units.