Spectral-kinetic properties and efficiency of singlet oxygen generation by some dipyrromethenes

Computational Investigation on the Photophysical Properties of Halogenated Tetraphenyl BODIPY

“…Alternatively, if the T 2 energy is assumed to be underestimated, then this state should be at a wavelength of about =770 nm (frequency =13000 cm -1 ), that is 110 nm shorter than the calculated value, with the same S 1 T 2 SOC-ME's to provide an agreement with experimental fluorescence quantum yield. 16 The fluorescence efficiency in BrPhaBDP is observed experimentally as =0.03 14,16,17 which is close to the MolSOC calculation of ME=0.01 (Table 2)…”

“…The energy gap between the T 3 and S 1 states for ClPhaBDP is wider and coincide well with the experimental and calculated  of about 0.3 and 0.1, respectively. 17 The fluorescence efficiency of the halogen-unsubstituted molecule is close to unity, 15 independently of the ordering of the excited states, although the calculated results are in better agreement with experimental data if S 1 is lower than T 3 , giving =0.88, but compared to assuming S 1 to be higher in energy, the difference is small, =0.94. states and their emission spectra were calculated using HSE06&6-311G(d).…”

“…However, this has not observed experimentally. 7,13,14,16,17 Instead, the opposite trend was observed when comparing di-iodine and di-bromine substituted compounds, where I 2 -tetraphenyl-aBDP exhibits a quite high quantum fluorescence of about γ=0.33, whereas Br 2 -tetraphenyl-aBDP has almost negligible fluorescence with γ=0.03 and Cl 2 -tetraphenyl-aBDP again appears to display a smaller rate of ISC, with γ=0.28.…”

“…These experimental results agreed well with the observed generation of photosensitized ( 1 O 2 ) by these molecules, where the most effective sensitization was not for the I 2 -substituted compound, having a triplet yield of 0.12, but rather for the Br 2 -substituted sensitizer (triplet yield of 0.83-0.89). 7,17 Previous computational work have not been able to explain this anomalous I/Br sensitization.…”

Сравнительные Исследования Фотофизических Свойств Димегина, Фотодитазина И Радахлорина

“…Информация о фотофизических свойствах фотосенсибилизаторов для фотодинамической терапии и флуоресцентной диагностики имеет большое практическое значение. Поэтому исследования этих свойств активно ведутся [1][2][3][4][5][6][7][8][9][10], в том числе и по отношению к димегину, фотодитазину и радахлорину. Основными фотофизическими свойствами фотосенсибилизаторов, определяющими их фотодинамическую активность, являются эффективность генерации синглетного кислорода и его время жизни в исследуемой среде.…”