A comparative study of the two-photon absorption properties of new three-branched molecules - Sumanene and triphenylene derivatives

Using density-functional theory and ZINDO-SOS method, we carry out a comparative study of the two-photon absorption (TPA) properties of sumanene and triphenylene derivatives. The results indicate that sumanene and triphenylene derivatives have relatively large TPA cross-sections and the high transparency. And the TPA cross-section increases as strength of donor/acceptor and conjugation length increase. In comparison with classical octupolar compounds, there exists stronger interaction between the branches of sumanene and triphenylene derivatives. Compared with triphenylene derivatives, the bowl-shaped structure of sumanene segment has an important effect on TPA of sumanene derivatives. It blocks electron transitions on the interior of sumanene segment and from the peripheric groups to molecular center.