Synthesis and Characterization of New o‐Carboranes‐Based Aggregation‐Induced Emission Molecules with Ultra‐Large Stokes Shift

Four o‐carborane‐based aggregation‐induced emission molecules with ultra‐large Stokes shifts were designed and synthesized. To explore the origin of the ultra‐large Stokes shifts (Δλ ≈ 268–294 nm) of the four target molecules, a new molecule named CZ‐Ph‐PO was synthesized by replacing the o‐carborane unit in CZ‐CB‐PO with a benzene ring. It was found that the ultra‐large Stokes shift was the result of the combined action of diphenylphosphinyl and o‐carborane, in which o‐carborane was the key group. In addition, combined with the single crystal structure analysis, the effect of halogens on molecular photophysical properties was investigated. Our work provides a reference for the design and synthesis of o‐carborane‐based fluorescent molecules with ultra‐large Stokes shifts. In this paper, o‐carborane‐based fluorescent molecules with halogenated 9‐phenylcarbazole subunits were designed and synthesized. The combined action of diphenylphosphinyl and o‐carborane causes the ultra‐large Stokes shifts (Δλ≈268–294 nm) of four AIE molecules.