Computational insights into two-photon absorption of centrosymmetric organoboron complexes

In the present work we studied the set centrosymmetric organoboron complexes containing BF2 groups. To that end, we employed ab initio quantum chemistry methods (RI-CC2 method and cc-pVDZ basis set) to study the symmetry-allowed electronic two-photon transition to the lowest excited state of 1Ag symmetry, considering both the effect of core topology as well as substituent. The results indicate that substituents with strong electron-donating properties are the most optimal ones as far as the maximization of two-photon transition strength is concerned. The resulting D-A-A-D architecture leads to the two-photon absorption cross-section values reaching 3000 GM.