Predicting Absorption And Emission Maxima Of Polycyclic Aromatic Azaborines: Reliable Transition Energies And Character

Polycyclic aromatic azaborines have potential applications as luminophores, novel fluorescent materials, organic light-emitting diodes, and fluorescent sensors. Additionally, their relative structural simplicity should allow the use of computational techniques to design and screen novel compounds in a rapid manner. Herein, the absorption and emission maxima of twelve polycyclic aromatic BN-1,2-azaborine analogues containing the N-BOH moiety were examined to determine a methodology for reliably predicting both the energy and character (local excitation [LE] vs charge transfer [CT]) of the absorption and emission maxima for these compounds. The necessity of implicit solvation models was also investigated. The cam-QTP(01) functional with a small, double-zeta quality basis set provides reliable data compared to EOM-CCSD/cc-pVDZ single-point computations. Of note, commonly used functionals for these applications (B3LYP and omega B97xD) struggle to provide reliable results for both the energy and LE character of the transitions relative to EOM-CCSD computations.