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.