The effect of substituting o‐carborane into the most sterically hindered positions of phenanthrene and benzo(k)tetraphene is reported. Synthesised via a Bull‐Hutchings‐Quayle benzannulation, the crystal structures of these non‐linear polycyclic aromatics exhibited the highest aromatic deformation parameters observed for any reported carborane compound to date, with the largest carboranyl C‐C bond length of all organo‐substituted o ‐carboranes. Photoluminescence studies of these compounds demonstrated efficient intramolecular charge‐transfer, leading to aggregation induced emission properties. Additionally, an unusual low‐energy excimer was observed for the phenanthryl compound. These are two new members of the family of carborane‐functionalised non‐linear polycyclic aromatics notable for their peculiar structures and multi‐luminescent properties.
Materials by design for sustainable solutions in the energy, medical, transport, and engineering sectors
