Halochrome Molekeln 4. Mitteilung. Chromogene Verbindungen durch Cyclisierung von [2-(Benzothiazol-2-yl)amino-4-(diäthylamino)phenyl]heteroaryliumsalzen: Synthese und acidobasisches Verhalten
✍ Scribed by Hugo Ziegler; Heinz Balli
- Publisher
- John Wiley and Sons
- Year
- 1983
- Tongue
- German
- Weight
- 880 KB
- Volume
- 66
- Category
- Article
- ISSN
- 0018-019X
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✦ Synopsis
Halochromic Molecules. Chromogenic Compounds by Cyclization of [2‐(Benzothiazol‐2‐yl)amino‐4‐(diethylamino)phenyl]heteroarylium Salts: Synthesis and Acidobasic Behaviour
Coloured [2‐(Benzothiazol‐2‐yl)amino‐4‐(diethylamino)phenyl]heteroarylium salts are deprotonated to colourless spiro‐compounds. The preparation of these products is described and their structure is explained by ^1^H‐NMR and UV/VIS spectroscopy. An investigation of the halochromic properties is carried out by spectro‐photometric determination of ε~pH~*‐ and εH~0~*‐curves in buffered MeOH/H~2~O solutions. p__K__*‐Values are determined, and the complex protonation equilibria are discussed. One of the heteroarylium salts does not form a spiro‐compound by deprotonation, but it is stabilized by a σ‐bond resonance.