The photoluminescence behaviour of monosubstituted non-benzenoid polycyclic-aromatic-substituted <i>ortho</i> -carboranes

<i>Ortho</i>-Carborane is a cluster compound known for its ability to exhibit stimuli-responsive optical behaviour when substituted with aromatic fluorophores. Here, we describe the synthesis of two such compounds: 1-(4'-naphtho[2,3-<i>b</i>]thiophenyl)-<i>ortho</i>-carborane and 1-(4'-benzo[1,2-<i>b</i>;4,5-<i>b</i>']dithiophenyl)-<i>ortho</i>-carborane. Optical studies reveal complex electronic and photoluminescent behaviour including intramolecular charge transfer (ICT), excimer emission, and aggregation-induced emission (AIE).