Influence of the molecular structure on the quenching of triplet states of porphyrins by molecular oxygen

Ganzha, V. A.; Gurinovich, G. P.; Джагаров, Б. М.; Egorova, G. D.; Sagun, E. I.; Шульга, А. М.

doi:10.1007/bf00659485

Cited by 26 publications

(25 citation statements)

References 2 publications

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“…40 We have determined that the singlet oxygen quantum yield of Chl is φ ∆ = 0.44 ± 0.05 in toluene (obtained by monitoring the intensity of singlet oxygen phosphorescence using porphine as the standard sensitizer, φ ∆ = 0.67 ± 0.06). 41 Upon incorporation into a cell, Chl clearly localizes outside the nucleus in the cell cytoplasm with a distribution that appears to be quite inhomogeneous ( Figure 3b). At present,…”

Section: General Characterization Of Tmpyp and Chlmentioning

confidence: 99%

Singlet Oxygen in a Cell: Spatially Dependent Lifetimes and Quenching Rate Constants

2008

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Singlet molecular oxygen, O 2 (a 1 ∆ g ), can be created in a single cell from ground state oxygen, O 2 (X 3 Σ g -), upon focused laser irradiation of an intracellular sensitizer. This cytotoxic species can subsequently be detected by its 1270 nm phosphorescence (a 1 ∆ g → X 3 Σ g -) with subcellular spatial resolution. The singlet oxygen lifetime determines its diffusion distance and, hence, the intracellular volume element in which singlet-oxygen-initiated perturbation of the cell occurs. In this study, the time-resolved phosphorescence of singlet oxygen produced by the sensitizers chlorin (Chl) and 5,10,15,20-tetrakis(N-methyl-4-pyridyl)-21H,23H-porphine (TMPyP) was monitored. These molecules localize in different domains of a living cell. The data indicate that (i) the singlet oxygen lifetime and (ii) the rate constant for singlet oxygen quenching by added NaN 3 depend on whether Chl or TMPyP was the photosensitizer.These observations likely reflect differences in the chemical and physical constituency of a given subcellular domain (e.g., spatially-dependent oxygen and NaN 3 diffusion coefficients) and, as such, are evidence that singlet oxygen responds to the inherent heterogeneity of a cell.Thus, despite a relatively long intracellular lifetime, singlet oxygen does not diffuse a great distance from its site of production. This is a consequence of an apparent intracellular viscosity that is comparatively large.3

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Section: General Characterization Of Tmpyp and Chlmentioning

confidence: 99%

Singlet Oxygen in a Cell: Spatially Dependent Lifetimes and Quenching Rate Constants

2008

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“…Reducing the pyrrole ring (going from prophyrin to chlorin) does not produce a significant difference between ϕ Δ and ϕ ST [29,30]. In our instance, ϕ Δ was significantly decreased, especially for H 2 TAC nb .…”

Section: Experimental Synthesis Norborn-5′-eno[b]tetraazachlorin (Hmentioning

confidence: 84%

“…Various reasons were possible for this decrease. First of all, it will be necessary in further studies to eliminate or account for the decrease of ϕ ST and to shorten the lifetime of the T 1 level (for the studied compounds [29,30] it was 200-600 nsec). It is noteworthy that ϕ ST was estimated as ~0.4 for H 2 TAC t [15], which clearly did not correspond to ϕ Δ = 0.07.…”

Section: Experimental Synthesis Norborn-5′-eno[b]tetraazachlorin (Hmentioning

confidence: 99%

Spectral-luminescence properties of a norbornene-substituted tetraazachlorin and its metal complexes

et al. 2010

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The spectral-luminescence properties of a tetraazachlorin derivative with a norbornene fragment annelated to a reduced pyrrole ring and its complexes with zinc and palladium have been studied at 293 and 77 K. For the norbornene-substituted free base, differences in fluorescence from unsubstituted tetraazachlroin and its dibenzobarrelene-substituted analog are found. The fluorescence lifetime is observed to rise by ~7 times for the free base and by ~1.6 ties for the Zn complex on going from 293 to 77 K. An essential dependence of the photophysical parameters on the nature of the solvent is noted. The fluorescence polarization spectrum of the norbornene-substituted tetraazachlorin reveals in the Soret band region at least four electronic transitions. For the Pd complex, weak phosphorescence in the near IR region has been detected; the 0-0 band maximum is at 990 nm and the singlet-triplet interval amounts to 5800 cm -1 , which is larger by 400 cm -1 than for Pd tetraazaporphine. The quantum yields of the photosensitized formation of singlet oxygen have been determined using a relative luminescence method.

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“…За φ ст принимали величину 0.063 в бензоле, измерен-ную в присутствии кислорода воздуха, [13] а за γ ст -величину 0.62 в бензоле, найденную химическим методом. [14] Последнее значение находится в хорошем согласии с результатом усред-нения значений γ cт , полученных люминесцентным методом в ССl 4 , [15] толуоле [16] и бензоле. [17] В фотохимических опытах концентрация соед.…”

Section: эсп (Chclunclassified

Synthesis, Spectral, Luminescence and Photochemical Properties of the Chlorin е6 Tricationic Derivative with Trimethylammonio Groups

Venediktov¹,

Tulikova²,

Rozhkova³

et al. 2017

MHC

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Influence of the molecular structure on the quenching of triplet states of porphyrins by molecular oxygen

Cited by 26 publications

References 2 publications

Singlet Oxygen in a Cell: Spatially Dependent Lifetimes and Quenching Rate Constants

Singlet Oxygen in a Cell: Spatially Dependent Lifetimes and Quenching Rate Constants

Spectral-luminescence properties of a norbornene-substituted tetraazachlorin and its metal complexes

Synthesis, Spectral, Luminescence and Photochemical Properties of the Chlorin е6 Tricationic Derivative with Trimethylammonio Groups

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