BF2-azadipyrromethenes: probing the excited-state dynamics of a NIR fluorophore and photodynamic therapy agent.
BF(2)-Azadipyrromethene dyes are a promising class of NIR emitter (nonhalogenated) and photosensitizer (halogenated). Spectroscopic studies on a benchmark example of each type, including absorption (one and two photon), time-resolved transient absorption (ps-ms) and fluorescence, are reported. Fast photodynamics reveal that intense nanosecond NIR fluorescence is quenched in a brominated analog, giving rise to a persistent (21 μs) transient absorption signature. Kinetics for these changes are determined and ascribed to the efficient population of a triplet state (72%), which can efficiently sensitize singlet oxygen formation (ca. 74%), directly observed by (1)Δ(g) luminescence. Photostability measurements reveal extremely high stability, notably for the nonhalogenated variant, which is at least 10(3)-times more stable (Φ(photodeg.) = < 10(-8)) than some representative BODIPY and fluorescein dyes.
University of Bordeaux/CNRS, Institut des Sciences Moléculaires, 351, crs de la Libération, 33405 Talence, France.
Pinar
P
Batat
Martine
M
Cantuel
Gediminas
G
Jonusauskas
Luca
L
Scarpantonio
Aniello
A
Palma
Donal F
DF
O'Shea
Nathan D
ND
McClenaghan
D005453:Fluorescence; D054879:Halogenation; D006219:Halogens / Q000737:chemistry*; D006801:Humans; D007700:Kinetics; D010777:Photochemistry / Q000379:methods*; D010778:Photochemotherapy / Q000379:methods*; D017785:Photons; D017319:Photosensitizing Agents / Q000737:chemistry* / Q000378:metabolism; D011166:Porphyrins / Q000737:chemistry* / Q000378:metabolism; D017434:Protein Structure, Tertiary; D026082:Singlet Oxygen / Q000737:chemistry; D013055:Spectrophotometry, Infrared
D006219:Halogens; D017319:Photosensitizing Agents; D011166:Porphyrins; D026082:Singlet Oxygen