Rational design of two photon absorbing Bodipy dyes

Two photon absorption is a nonlinear process which is of particular interest in various applications such as optical data storage, fluorescence imaging, O2 sensing and photodynamic therapy. These applications have created a strong demand for new dyes which have high two photon absorption cross section. In the two- photon absorption process there is an interaction of the two photons which are simultaneously absorbed by materials. For this purpose, we have designed and synthesized a novel class of distyryl-substituted boradiazaindacene (BODIPY) dyes which absorb two one photon in the green or two photons in the near IR regions of the (electromagnetic) spectrum and have D-A-D structure. As expected, as the strength of the donor groups which were introduced to the 3,5 position of the BODIPY core increase, absorption and emission maxima of the BODIPY dyes are shifted in the near IR regions of the spectrum. Furthermore, GM values increase due to the enhancement donor strength of the terminal groups. In summary, we have successfully synthesized a novel class of BODIPY derivatives which have large TPA cross section values.