Decay Kinetics of the Triplet Excited State of Lumiflavin

Abstract

Abstract— The rate of decay of the triplet state of lumiflavin in deaerated phosphate buffer at pH 6.9, has been studied using the flash photolysis technique, at various concentrations and flash energies. The decay of the transient appears as a mixture of first and second order processes, the relative importance of which depends on the experimental conditions. The following competitive reactions have been found to explain the course of the reaction of the triplet excited state of lumiflavin.

Indium induced band gap tailoring in AgGa1−xInxS2 chalcopyrite structure for visible light photocatalysis

“…[1][2][3][4][5] Especially, binary sulfides 6,7 are known for their efficient hydrogen production by water splitting due to their suitable band edge positions to reduce/oxidize water. In contrast, most of the oxide photocatalysts [8][9][10][11] possess the band structure that is not suitable for hydrogen production from water splitting.…”

AgGaS2-type photocatalysts for hydrogen production under visible light: Effects of post-synthetic H2S treatment

“…Thus, the AgGaS 2 samples treated at temperatures of 1073 and 1123 K under H 2 S flow exhibited higher photocatalytic activity by factors of up to 4 compared with those of the untreated sample and H 2 Streated samples at lower temperatures of 873 and 973 K. In order to understand this significant promotional effect, the detailed investigation on change in the structure of materials during the H 2 S-treatment was in order. Ga I -Ga I (2) 3.04 Ga II -Ga II (2) 3.04 Ga II -Ga II (2) 3.11 Ga-Ag(4) 3.86 Ga I -Ga II 3.28 Ga-Ga(4) 3.86 Ga I -Ga II (2) 3.30 Ga-Ag(4) 4.07 Ga I -Ga II (2) 3.33 Ga-S(4) 4.45 Ga I -Ga II (2) 3.45 a The data taken from Ref. [21].…”

“…Sulfide photocatalysts have been known to be active for hydrogen production from aqueous electrolyte solutions containing a sacrificial electron donor (Na 2 S or/and Na 2 SO 3 ) under visible light irradiation [1,2]. In an environmental application, these photocatalysts could be used for decomposition of the harmful H 2 S gas absorbed in alkaline water without such sacrificial electron donors [3,4].…”

Electrostatic Effects in the Photoreduction of Flavins by Edta

“…The values of k, at 5 x M and pH 7.0 are 7.6 x S K I , 8.8 x s-l, and 1.1 x s-l, respectively. The rate constant for lumiflavin has been found to be higher with values of k, = 1.4 x 10+j s -I (Naman and Tegner, 1986) and k, = 2.0 x s-I (Vaish and Tollin, 1970). Table 3.…”

“…1). Tegner, 1986;Vaish and Tollin. 1970;and Fritz et a/.. 1987b). ied by changing the dielectric constant of the medium (Laidler, 1987a).…”