In exploring the viability of o-carborane for TADF applications, we conducted computations to analyze the energetics of single-molecule p-BrPh-oC-PhEPy and DMA-oC-PhEPy structures (Table ). In p-BrPh-oC-PhEPy, the lowest singlet corresponds to a local excitation (LE) of the PhEPy subunit, whereas in DMA-oC-PhEPy, it represents a charge transfer (CT) state between DMA and PhEPy. The calculations reveal that in both structures, the lowest singlet excited state is energetically degenerate with a triplet state, suggesting the potential for TADF arising from a narrow singlet-triplet energy gap. The presence of intermolecular and intramolecular CT states is interpreted in terms of orbital analysis. Figure shows trimers extracted from the crystal structures with σ…π interactions. In p-BrPh-oC-PhEPy, the weak donor properties of p-BrPh result in transitions involving delocalized orbitals between the PhEPy subunits of two monomers. Interestingly, the trimer exhibits CT states with high polarization, as evidenced by the transition dipole moment (μ=43 D for CT1 and μ=38 proportions are referring to volumes (v/v). 1-Ethynylpyrene was synthesized from 1bromopyrene following literature procedures .