TY - JOUR

T1 - Influence of medium viscosity on photophysical properties of kynurenic acid and kynurenine yellow

AU - Zelentsova, E. A.

AU - Sherin, P. S.

AU - Tsentalovich, Yu P.

AU - Sagdeev, R. Z.

PY - 2017/2/1

Y1 - 2017/2/1

N2 - Dependences of the fluorescence and triplet state quantum yields of kynurenic acid (1) and kynurenine yellow (2) in water—glycerol mixtures on medium viscosity have been studied. The main channel of the singlet excited state decay of compound 1 is the intersystem crossing, which rate weakly depends on the viscosity; only a small (approximately 1.5-fold) increase in the fluorescence yield was found for this compound with the increase of the solution viscosity from 0.84 cP (aqueous solution) to 78 cP (86% glycerol). The deactivation of the S1 state of compound 2 is caused mainly by the internal conversion, and a noticeable increase of the fluorescence yield (approximately 3-fold), as well as the change in the photolysis product yields, was observed with the increasing percentage of glycerol in the mixture. The triplet state quantum yields for compounds 1 and 2 remained unchanged with the variation of the glycerol content in the mixture.

AB - Dependences of the fluorescence and triplet state quantum yields of kynurenic acid (1) and kynurenine yellow (2) in water—glycerol mixtures on medium viscosity have been studied. The main channel of the singlet excited state decay of compound 1 is the intersystem crossing, which rate weakly depends on the viscosity; only a small (approximately 1.5-fold) increase in the fluorescence yield was found for this compound with the increase of the solution viscosity from 0.84 cP (aqueous solution) to 78 cP (86% glycerol). The deactivation of the S1 state of compound 2 is caused mainly by the internal conversion, and a noticeable increase of the fluorescence yield (approximately 3-fold), as well as the change in the photolysis product yields, was observed with the increasing percentage of glycerol in the mixture. The triplet state quantum yields for compounds 1 and 2 remained unchanged with the variation of the glycerol content in the mixture.

KW - fluorescence

KW - kynurenic acid

KW - kynurenine yellow

KW - triplet state

KW - water—glycerol mixtures

UR - http://www.scopus.com/inward/record.url?scp=85021790223&partnerID=8YFLogxK

U2 - 10.1007/s11172-017-1727-6

DO - 10.1007/s11172-017-1727-6

M3 - Article

AN - SCOPUS:85021790223

VL - 66

SP - 267

EP - 272

JO - Russian Chemical Bulletin

JF - Russian Chemical Bulletin

SN - 1066-5285

IS - 2

ER -