Synthesis, characterization and optical properties of new tetrafluorenyl-porphyrins peripherally functionalized with conjugated 2-fluorenone groups

The synthesis of new meso -tetrafluorenylporphyrins peripherally functionalized with various 2-ethynyl fluorenyl and/or 2-ethynyl fluorenonyl arms is presented. The impact of these fluorenone units on their linear and nonlinear optical properties is also investigated. Thus, two-photon absorption and singlet oxygen photosensitising properties are evaluated. Improvement of these properties relative to their analogues featuring non-oxidized fluorenyl terminal groups, which make the molecules presented quite appealing for combined 2-photon-based photodynamic therapy (PDT) and imaging, is then briefly discussed. Star shaped porphyrins decorated with external fluorenonyl arms have been isolated. Their luminescence and selected photophysical properties are discussed in the frame of two-photon-induced theranostics.