Functional dyes for molecular switching. Dihydroazulene/vinylheptafulvene photochromism: Effect of π-arylenes on the switching behavior
✍ Scribed by Spreitzer, Hubert ;Daub, Jörg
- Publisher
- John Wiley and Sons
- Year
- 1995
- Tongue
- English
- Weight
- 556 KB
- Volume
- 1995
- Category
- Article
- ISSN
- 0947-3440
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✦ Synopsis
Abstract
The reversible interconversion of dihydroazulene (DHA) and vinylheptafulvene (VHF) can be utilized to switch a number of physical properties. This communication reports on a fluorescent switch. By a multistep sequence involving an [8 + 2] cycloaddition route 9‐anthracenyl‐1,4‐phenylene was covalently attached to C‐2 of the DHA chromophore affording DHA‐1 which undergoes complete and clean photochemical ring opening to vinylheptafulvene VHF‐1. The latter is thermally reverted to DHA‐1. The kinetics and the energetics of the thermal back reaction are discussed. On/off switching of luminescence was investigated: DHA‐1 displays fluorescence whereas VHF‐1 is nonfluorescent at ambient temperature.