An exploration of new avenues regarding deep tissue penetration and higher singlet oxygen efficiencies: novel near-IR photosensitizers for photodynamic therapy

A series of novel BODIPY-bearing electron-withdrawing groups at the meso position are reported here. According to the optical measurements, it may be clearly seen that the introduction of electron-donating groups into 3,5-positions and the presence of electron-withdrawing groups at the meso position of the BODIPY core resulted in spectacular bathochromic shifts (up to ~ 304nm), and the projected photosensitizers had absorption bands in the therapeutic window of the electromagnetic spectrum (600–900nm). The absorption maxima of compounds 4, 5, 6, and 7 were at 886nm, 890nm, 760nm, and 761nm, respectively.