Flash photolysis of aromatic sulfur molecules

Thyrion, F. C.

doi:10.1021/j100631a002

Cited by 83 publications

(53 citation statements)

References 3 publications

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“…S11 †), consistent with previous observations. 39 A summary of the screening results (Fig. 3b) of all scavenger candidates using the low concentration TTA-UC system is given in Table 1.…”

Section: Resultsmentioning

confidence: 99%

Robust triplet–triplet annihilation photon upconversion by efficient oxygen scavenging

Dzebo

Moth‐Poulsen

Albinsson

2017

Photochem Photobiol Sci

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We hereby present a simple method for reducing the effect of oxygen quenching in Triplet-Triplet Annihilation Upconversion (TTA-UC) systems. A number of commercially available thioethers and one thiol have been tested as singlet oxygen scavengers. Recording of the upconverted emission from a well-studied PdOEP (sensitizer)-DPA (annihilator/emitter) couple has been made over time with steady-state excitation capturing the steady-state kinetics of the TTA-UC process as the solubilized oxygen is depleted by reaction with the scavengers. The efficiency of the TTA-UC process is compared between chemical oxygen scavenging and mechanical removal by inert gas purging or the freeze-pump-thaw method. Selected methods are combined to explore the highest attainable TTA-UC quantum yield. A maximum TTA-UC quantum yield of 21% with the shortest UC onset time was obtained with dimethylthiomethane (DMTM) as the scavenger in an air-saturated solvent and slightly higher quantum yields were obtained in combination with other deoxygenation techniques. Samples containing DMTM displayed little decrease in the quantum yield over four hours of continuous high intensity irradiation, which illustrates the robustness of applying chemical oxygen removal in TTA-UC instead of more time-consuming mechanical processes that usually require specialized equipment.

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“…S11 †), consistent with previous observations. 39 A summary of the screening results (Fig. 3b) of all scavenger candidates using the low concentration TTA-UC system is given in Table 1.…”

Section: Resultsmentioning

confidence: 99%

Robust triplet–triplet annihilation photon upconversion by efficient oxygen scavenging

Dzebo

Moth‐Poulsen

Albinsson

2017

Photochem Photobiol Sci

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“…In Figs. 2(a-b) at t = 0 fs, the spectra contain two other features; a band between 425550 nm associated with the p-MePhS( X ) radical ( C ← X and B ← X absorption bands, violet bars); [15][16][17][34][35][36] and an underlying absorption that spans the whole λ probe region, which we have previously assigned to S n S 1 ESA using our prior EOM-CCSD/aug-cc-pVTZ calculations (green bars). following the red end of the probe window in Fig.…”

Section: (B)mentioning

confidence: 99%

Exploring the Energy Disposal Immediately After Bond-Breaking in Solution: The Wavelength-Dependent Excited State Dissociation Pathways of para-Methylthiophenol

et al. 2013

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A wavelength-resolved ( pump = 295, 285, 270 and 267 nm) photodissociation study of paramethylthiophenol (p-MePhSH) in ethanol solution has been performed using femtosecond transient absorption (TA) spectroscopy and the results compared with those from studies of the corresponding photodissociation in cyclohexane solution at 270 nm. Anisotropy spectra are used to identify the electronic character of the initially populated excited state(s). S-H bond fission is found to occur via the dissociative S 2 (1 1 πσ*) state, which can be populated directly, or by ultrafast non-radiative transitions from the S 3 (2 1 ππ*) state, or by very efficient tunneling from the S 1 (1 1 ππ*) state, depending on the excitation wavelength -in line with conclusions from

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“…In order to assign the transient absorption band, a mixed disulfide 6 having the N-oxypyridyl-2-thio moiety and the pchlorobenzenethio moiety was used. The p-chlorobenzenethio moiety was selected as a partner, because of its well-established transient absorption band at 510 nm (12)(13)(14), where an appreciable transient absorption band from 1 was not present. By the laser flash photolysis of mixed disulfide 6, two transient absorption bands were observed at 365 nm and 510 nm as shown in Fig.…”

Section: Assignment Of Transient Species From Disulfidementioning

confidence: 99%

Laser Flash Photolysis of 2,2′‐Dithiobls(pyridine N‐oxide): Reactivity of N‐Oxypyridyl‐2‐thio Radical

Alam

Watanabe

Ito

1996

Photochem & Photobiology

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Abstract— Reaction kinetics of radicals produced by the nanosecond laser flash photolysis of 2,2′‐dithiobis(pyridine N‐oxide) and related compounds have been studied. The transient absorption band at 360 nm was attributed to the radical in which the unpaired electron mainly localizes on the S atom (N‐oxypyridyl‐2‐thio radical). The reactivities of the radical for conjugated dienes are lower than those of the pyridyl‐2‐thio radical, suggesting that a considerable unpaired electron density on the S atom delocalizes onto the N‐oxypyridine moiety. The addition reaction rate of the radical to the conjugating diene was accelerated with hydrogen‐bonding solvents and with addition of the cation, which may stabilize the N+‐O‐ canonical structure, increasing the unpaired electron density on the S atom. By the photolysis of N‐hydroxypyridine‐2‐thione, the N‐O bond was predominantly dissociated producing a pyr‐idyl‐2‐thio radical. By the photolysis of its anion, photoejection took place followed by the N‐O bond fission, yielding pyridine‐2‐thione.

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Flash photolysis of aromatic sulfur molecules

Cited by 83 publications

References 3 publications

Robust triplet–triplet annihilation photon upconversion by efficient oxygen scavenging

Robust triplet–triplet annihilation photon upconversion by efficient oxygen scavenging

Exploring the Energy Disposal Immediately After Bond-Breaking in Solution: The Wavelength-Dependent Excited State Dissociation Pathways of para-Methylthiophenol

Laser Flash Photolysis of 2,2′‐Dithiobls(pyridine N‐oxide): Reactivity of N‐Oxypyridyl‐2‐thio Radical

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