Abstract
We have investigated the network of reactions observed for the photochromic 4′-hydroxy-6-nitroflavylium compound in aqueous solutions upon pH changes (including pH jump and stopped flow experiments) and light excitation. The changes observed in the NMR and UV/Vis spectra allowed identification of ten different forms in which this compound can be transformed depending on the experimental conditions. Equilibrium and kinetic constants have been determined. Compared with other members of the flavylium family, 4′-hydroxy-6-nitroflavylium is characterized by a large cis→trans isomerization barrier, and a very efficient hydration reaction. These peculiar features allow writing, reading, storing and erasing photonic information on 4′-hydroxy-6-nitroflavylium by a novel cyclic process that involves the following steps: write-lock/read/unlock/enable-erase/erase.
| Original language | English |
|---|---|
| Pages (from-to) | 1519-1526 |
| Number of pages | 8 |
| Journal | Chemistry - A European Journal |
| Volume | 10 |
| Issue number | 6 |
| DOIs | |
| Publication status | Published - 2004 |
Keywords
- Flavylium salts
- Heterocyles
- Molecular devices
- Optical memories
- Supramolecular chemistry
- Hydration
- Isomerization
- Nitrogen compounds
- Nuclear magnetic resonance
- pH effects
- Rate constants
- Kinetic constants
- Light excitation
- Reaction kinetics
- flavone derivative
- hydroxyl group
- nitro derivative
- aqueous solution
- article
- chemical reaction
- chemical reaction kinetics
- cis trans isomerism
- equilibrium constant
- hydration
- light
- nuclear magnetic resonance
- pH
- ultraviolet spectroscopy
- Acetophenones
- Alkenes
- Hydrogen-Ion Concentration
- Kinetics
- Light
- Molecular Structure
- Nitro Compounds
- Oxidation-Reduction
- Photochemistry
- Stereoisomerism