Solvent effects on two-photon absorption cross sections of a newly synthesized polymerization initiator

The solvent effects on the geometrical and electronic structures, as well as one- and two-photon absorption process of a newly synthesized asymmetrical photon polymerization initiator 4-vinylpyridine-4′-(N,N-diphenylamino)benene (VPDB) are studied, using the time-dependent hybrid density functional theory (DFT/B3LYP) in combination with polarized continuum model (PCM). The two-photon absorption cross sections of the compound in gas and solvents are calculated by employing the generalized three-state model. The numerical results show that the solvatochromic shift for charge transfer states takes red-shift and exhibits nonmonotonic behavior with respect to the polarity of solvents. The two-photon cross sections are enhanced in related to the solvent and the enhancement shows nonmonotonic trend according to the polarity of solvents. The compound has large TPA cross section and can be used as an excellent candidate for the two-photon photopolymerization initiators.