13 Photodynamic Therapy
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Fig. 13.5 a Halogen-substituted BODIPY and BODIPY dimer, b condensed BODIPY, and c azaBODIPY photosensitizing dyes
thienopyrrole-fused BODIPY dye, T-BODIPY-P1 (R = H), without any heavy atom
substitution shows a high ε (120,000 M
–1 cm
–1 ) around 690 nm, a moderate Φ fl value
(0.22), and relatively high Φ (0.42), BT (26,400 M
–1 cm
–1 ), and PP (50,400 M
–1
cm
–1 ) values (Fig. 13.5b) (Watley et al. 2015). In addition, the study on the influence of electron withdrawing and electron-donating groups on the
1 O 2 generation
properties of a series of T-BODIPY-P dyes (λ
abs
max = 688–738 nm, ε = 120,000–
287,000 M
–1 cm
–1 ) demonstrated that the electron withdrawing groups increase the
HOMO-LUMO energy gaps and Φ values. T-BODIPY-P4 (R = CH 3 ), T-BODIPYP5 (R = OCH 3 ), and T-BODIPY-P6 (R = OH) having electron-donating groups