Photochromic Spirotetrahydroazafluorenes:: Part V.: Why photochromic molecules with rigid region B exhibiting extremely fast bleaching process?

被引：19

作者：

Ahmed, SA ^{[1
]}

Dürr, H

机构：

[1] Assiut Univ, Fac Sci, Dept Chem, Assiut 71516, Egypt

[2] Univ Saarland, Fachbereich 11 2, D-6600 Saarbrucken, Germany

来源：

MOLECULAR CRYSTALS AND LIQUID CRYSTALS | 2005年 / 431卷

关键词：

flash photolysis; short-lived photochromes; spirotetrahydroazafluorenes;

D O I：

10.1080/15421400590947513

中图分类号：

O6 [化学];

学科分类号：

0703 ;

摘要：

Spirotetrahydroindolizines (THIs) 1a-g and Spirotetrahydroazafluorenes (THF) 2a-g were previously synthesized. The high reaction rate of the thermal 1,5-electrocyclization results in the half-lives of the colored betaines 2'a-g range from 3.9 to 5.4 ns, thus showing the existence of the shortest lived colored form observed so far for pyrazoline based photochromes. However, laser flash spectroscopy was successfully used for the determination of both the half-life and absorption maxima of the colored betaines 2'a-g. Time resolved transient spectroscopy shows the geometry of the betaines 2'a-g to be related to one of the two detectable intermediates 1'a-g or 1"a-g.

引用

页码：575 / 580

页数：6

共 18 条

[1]

Ahmed SA, 2000, J PHYS ORG CHEM, V13, P539, DOI 10.1002/1099-1395(200009)13:9<539::AID-POC296>3.0.CO

[2]

2-9

[3] Steric substituent effects of new photochromic tetrahydroindolizines leading to tunable photophysical behavior of the colored betaines [J].