Theoretical investigation on a series of heterocycle-based compounds with large two-photon absorption cross-sections

A series of heterocycle-based molecules using π-deficient (pyridinium) and π-excessive (pyrrole) heteroaromatic rings as acceptor and donor, respectively, have been designed and their two-photon absorption properties have been investigated theoretically by using the AM1 and ZINDO methods. On the basis of correct geometries and UV-VIS spectra, the positions and strengths of two-photon absorption of these molecules were reported. Our calculated results reveal that molecule F, which has the largest two-photon cross-section (2457.29×10−50 cm4 s photon−1) among studied molecules, is a more promising two-photon absorption material.