The essential role of the electronegativity perturbation in vibronic interactions in positively charged B,N-substituted acenes

Total electron-phonon coupling constants for the monocations (lHOMO) of B,N-substituted acene-series such as B3N3H6, B5N5H8, and B7N7H10 are estimated. The estimated lHOMO values of 0.357, 0.209, and 0.182 eV for B3N3H6, B5N5H8, and B7N7H10, respectively, are larger than those of 0.244, 0.173, and 0.130 eV for benzene, naphthalene, and anthracene, respectively. Furthermore, the lHOMO value for B,N-substituted polyacene (0.096 eV) is estimated to be larger than that for polyacene (0.036 eV). Stronger orbital interactions between B and N atoms in the highest occupied molecular orbitals (HOMO) in B,N-substituted acene-series than those between two neighboring carbon atoms in the HOMO in acene-series as a consequence of electronegativity perturbation on acene-series, are the main reason why the lHOMO values for B,N-substituted acene-series are larger than those for acene-series.