FLUORESCENCE AND EXCITED-STATE PROTON-TRANSFER OF PYRENE-3-CARBOXALDEHYDE

被引：9

作者：

ACUNA, AU

OTON, JM

机构：

[1] Instituto de Química Fisica Rocasolano, C.S.I.C., Serrano 119

来源：

JOURNAL OF LUMINESCENCE | 1979年 / 20卷 / 04期

关键词：

D O I：

10.1016/0022-2313(79)90008-5

中图分类号：

O43 [光学];

学科分类号：

070207 ; 0803 ;

摘要：

In very dilute water solutions, ca 10-7 M, pyrene-3-carboxaldehyde fluoresces with a high quantum yield, øF = 0.98. This emission is quenched at low pH and, if the proton activity is high enough, a new weak, red shifted fluorescence appears. These effects are explained by the existence of a fast proton transfer in the excited state. The emitting singlet is believed to be 6-7 orders of magnitude more basic than the ground electronic state. By measuring the changes in fluorescence intensity and lifetime of pyrene-3-carboxaldehyde as a function of pH, a value for the quenching rate constant k2 = (2.2 ± 0.3) × 1010 M-1 s-1 was obtained. The quenching of the neutral form fluorescence is proposed to be produced by the protonation of the excited aldehyde, followed by a fast radiationless deactivation of the conjugated acid, before prototropic equilibrium can be attained. © 1979.

引用

页码：379 / 385

页数：7

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