Tetra(1,1,4,4-tetramethyl-6,7-tetralino)porphyrazine as a novel luminescence sensor of laser-induced singlet oxygen generation in solutions

Physical Mechanisms of Generation and Deactivation of Singlet Oxygen

“…The second group of compounds are phthalocyanines, naphthalocyanines, and porphyrazines, which exhibit strong delayed fluorescence upon energy transfer from two O 2 ( 1 Δ g ) molecules. , The luminescence is emitted in the visible (∼700 nm) region, and its quantum yield exceeds that of the a → X phosphorescence of O 2 ( 1 Δ g ) by 2−4 orders of magnitude. The signal is easily detected in laser-pulsed time-resolved studies; thus, the method may be very useful for singlet oxygen measurements in numerous systems.…”

“…On the basis of correlations with the ease of ionization of the quencher, these events have been explained by a CTinduced process, where the deactivation of the initially formed singlet encounter complex 1 (Q 1 ∆) EC is enhanced by the formation of a singlet 1 (Q 1 ∆) CT exciplex, which is stabilized by the transfer of electric charge from the quencher to the oxygen molecule. This species decays mainly by isc to a triplet CT ground-state complex, 3 (Q 3 Σ) CT , which finally dissociates to the products Q and O 2 ( 3 Σ g -), without charge separation in most cases.…”

“…The activation volume, ∆V CT # ) ∆V obs # -∆V C ) ∆V CT + ∆V p # , for the reaction from the encounter complex to the transition state of isc from 1 (Q 1 ∆) CT to 3 (Q 3 Σ) CT exciplexes can thus be easily calculated from the data shown in Figure 18. For several substituted benzenes, Okamoto and Tanaka 202 found a correlation between ∆V CT # and the ionization potential of the quencher which is in accordance with a CT-induced process.…”

“…The development of both applications and novel observation techniques has strongly accelerated during the past few years. Significant recent advances include, for example, the development of novel luminescent singlet oxygen probes, [1][2][3][4] the time-resolved detection of O 2 ( 1 ∆ g ) in a transmission microscope, 5 the first time-resolved measurements of singlet oxygen luminescence in vivo, 6 and the observation of oxygen quenching of triplet-excited single molecules. 7 Experimental and theoretical studies on the mechanisms of photosensitized formation of excited O 2 states and of their deactivation have been performed for almost 40 years.…”

Effect of femtosecond laser radiation on morphofunctional state of neoplasm in vitro

“…[5]. LOE allows spectrum selective activation and, at high energy density, cell destruction through photogeneration of singlet oxygen: 3 О 2 + hν → 1 O 2 → (0,98 эв) → bioeffect: that becomes apparent in structural changes of biomembrane [6,7].…”