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

A series of heterocycle-based molecules using pi-deficient (pyridinium) and pi-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 x 10(-50) cm(4) s photon(-1)) among studied molecules, is a more promising two-photon absorption material. (c) 2005 Elsevier B.V. All rights reserved.