Photochemical study of substituted s-triazines

Douarre, L.; Arnaud, René; Lemaire, Jácques; Deflandre, André; Richard, Hervé

doi:10.1016/1010-6030(95)04271-7

Cited by 6 publications

(6 citation statements)

References 7 publications

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“…1. On the other hand, the spectrum observed at 25 °C shows somewhat blurred vibrational structure and only one peak at 314 nm in the UV-B range as reported by Douarre et al and Herzog et al 10,21 The molar absorption coefficients of EHT and DBT in ethanol at 25 °C were obtained to be 130 000 mol −1 dm 3 cm −1 at 314 nm and 110 000 mol −1 dm 3 cm −1 at 311 nm, respectively. It should be mentioned here that the molar absorption coefficients of EHT and DBT significantly increase at 77 K. In the analysis of data, the concentrations were corrected for shrinkage of the solution upon freezing at 77 K (20% by volume).…”

Section: Uv Absorption and Emission Spectrasupporting

confidence: 66%

“…6,7 EHT possesses multiple chromophores that yield a large molar absorption coefficient of 119 500 mol −1 dm 3 cm −1 in oil at 314 nm and 134 000 mol −1 dm 3 cm −1 in methanol at 312 nm. 6,9,10 The low solubility of EHT can be understood as a consequence of the high symmetry. 6 Diethylhexylbutamido triazone (DBT, dioctylbutamido triazone, Uvasorb HEB, Scheme 1) can be regarded as an improved version of EHT.…”

Section: Introductionmentioning

confidence: 99%

“…[11][12][13][14][15][16][17] Several studies on the photostability, spectral profile and phototoxicity of EHT and DBT have been reported. 10,[18][19][20][21][22][23][24][25][26] However, to our best knowledge, the energy levels of the excited states of EHT and DBT have not been reported.…”

Section: Introductionmentioning

confidence: 99%

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Photoexcited triplet states of UV-B absorbers: ethylhexyl triazone and diethylhexylbutamido triazone

Tsuchiya

Kikuchi

Oguchi-Fujiyama

et al. 2015

Photochem Photobiol Sci

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The excited states of UV-B absorbers, ethylhexyl triazone (EHT) and diethylhexylbutamido triazone (DBT), have been studied through measurements of UV absorption, fluorescence, phosphorescence, triplet-triplet absorption and electron paramagnetic resonance spectra in ethanol. The energy levels of the lowest excited singlet (S1) and triplet (T1) states and quantum yields of fluorescence and phosphorescence of EHT and DBT were determined. In ethanol at 77 K, the deactivation process of EHT and DBT is predominantly fluorescence, however, a significant portion of the S1 molecules undergoes intersystem crossing to the T1 state. The observed phosphorescence spectra, T1 lifetimes and zero-field splitting parameters suggest that the T1 state of EHT can be assigned to a locally excited (3)ππ* state within p-(N-methylamino)benzoic acid, while the T1 state of DBT can be assigned to a locally excited (3)ππ* state within p-(N-methylamino)benzoic acid or p-amino-N-methylbenzamide. The quantum yields of singlet oxygen generation by EHT and DBT were determined by time-resolved near-IR phosphorescence measurements in ethanol at room temperature. EHT and DBT did not exhibit significantly antioxidative properties by quenching singlet oxygen, in contrast to the study by Lhiaubet-Vallet et al.

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Section: Uv Absorption and Emission Spectrasupporting

confidence: 66%

Section: Introductionmentioning

confidence: 99%

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Photoexcited triplet states of UV-B absorbers: ethylhexyl triazone and diethylhexylbutamido triazone

Tsuchiya

Kikuchi

Oguchi-Fujiyama

et al. 2015

Photochem Photobiol Sci

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“…It was reported that the rate of decomposition of some triazines has been increased up to 3-11 times using acetone as sensitizer (Burkhard and Guth, 1976;Rejto et al, 1983). Photochemical studies of certain triazine derivatives in both methanol and aqueous solutions and identification of their final products have also been reported (Pape and Zabik, 1970;Donnare et al, 1996). Furthermore, it is reported that the rate of disappearance of methyland halo-substituted s-triazine is dependent on the nature of the halogen and alkyl substituents and the solvent employed (Ruzo et al, 1973).…”

Section: Introductionmentioning

confidence: 99%

Oxidative Degradation of Triazine Derivatives in Aqueous Medium: A Radiation and Photochemical Study

Jacob¹,

Veleeparambil²,

Aravindakumar³

et al. 2000

J. Agric. Food Chem.

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Pulse and steady state radiolysis techniques have been used to determine the bimolecular rate constants and to investigate the spectral nature of the intermediates and the degradation induced by hydroxyl radicals ((*)OH) with 1,3,5-triazine (T), 2,4, 6-trimethoxy-1,3,5-triazine (TMT), and 2,4-dioxohexahydro-1,3, 5-triazine (DHT) in aqueous medium. A competitive kinetic method with KSCN as the (*)OH scavenger was used to determine the rate constants for the reaction of (*)OH with T, TMT, and DHT. The bimolecular rate constants are 3.4 x 10(9), 2.06 x 10(8), and 1.61 x 10(9) dm(3) mol(-)(1) s(-)(1) respectively, for T, TMT, and DHT at pH approximately 6. The transient absorption spectra obtained from the reaction of (*)OH with T, TMT, and DHT have single absorption maxima at 320, 300, and 300 nm, respectively, and were found to undergo a second-order decay. The formation of TOH(*) [C(6)OH-N(5)-yl radical], TMTOH(*) [N(5)OH-C(6)-yl radical], and DHT(*) [C(6)-yl radical] is proposed from the initial attack of (*)OH with T, TMT, and DHT, respectively. A complete degradation of TMT (10(-3) mol dm(-3)) was obtained after absorbed doses of 5 kGy in N(2)O-saturated solutions and 16 kGy in aerated solutions. A similar degradation pattern was obtained with DHT in N(2)O-saturated solutions. Complete degradation was observed with an absorbed dose of 7 kGy. On the basis of the results from both pulse and steady state radiolysis, a possible reaction mechanism involving (*)OH-mediated oxidative degradation is proposed. A complete photodecomposition of DHT was also observed in the presence of ferric perchlorate using ultraviolet light at low pH. Photoinduced electron transfer between Fe(III) and DHT in the Fe(III)-DHT complex and subsequent formation of DHT(*) are proposed to be the major processes that lead to the complete degradation of DHT at pH 3.

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“…For example, the 2‐ethylhexyl derivative is marketed as a sunscreen ingredient by BASF (Research Triangle Park, CA) under the trade name Univul® T150. The photobehavior of some substituted s ‐triazines has been previously investigated (13); in particular, the closely related octyl triazone (4,4′,4″‐[l,3,5‐triazine‐2,4,6‐triyltriimino]tris‐[2‐ethyl‐hexyl] benzoate) has been reported to undergo photoinduced scission of an NH‐Ph bond with low quantum yields (10 −6 ), when irradiated at 313 nm in air‐equilibrated methanol (13). The resulting photoproduct possesses a primary amino group attached directly to the s ‐triazine core.…”

Section: Introductionmentioning

confidence: 99%

Photophysical Properties of Methyl Triazone Included in MCM‐41^¶

Ricci¹,

Chrétien²,

Sayari³

et al. 2005

Photochem & Photobiology

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Methyl triazone (4,4′,4″‐[l,3,5‐triazine‐2,4,6–triyItriimino]tris‐trimethyl benzoate) has been included in mesoporous MCM‐41 (Mobil's composition of matter‐41) silica, and its fluorescence emission has been compared in solution and in the solid state. Although inclusion does not affect significantly the absorption properties, a fluorescence emission shift and a behavior similar to the solid state has been observed by increasing the loading. It is believed that this observation reflects molecular aggregation inside the MCM‐41 channels. The potential of formulations of this type for sunscreen applications is discussed.

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Photochemical study of substituted s-triazines

Cited by 6 publications

References 7 publications

Photoexcited triplet states of UV-B absorbers: ethylhexyl triazone and diethylhexylbutamido triazone

Photoexcited triplet states of UV-B absorbers: ethylhexyl triazone and diethylhexylbutamido triazone

Oxidative Degradation of Triazine Derivatives in Aqueous Medium: A Radiation and Photochemical Study

Photophysical Properties of Methyl Triazone Included in MCM‐41^¶

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Photochemical study of substituted s-triazines

Cited by 6 publications

References 7 publications

Photoexcited triplet states of UV-B absorbers: ethylhexyl triazone and diethylhexylbutamido triazone

Photoexcited triplet states of UV-B absorbers: ethylhexyl triazone and diethylhexylbutamido triazone

Oxidative Degradation of Triazine Derivatives in Aqueous Medium: A Radiation and Photochemical Study

Photophysical Properties of Methyl Triazone Included in MCM‐41¶

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Photophysical Properties of Methyl Triazone Included in MCM‐41^¶