Änderung der Lichtabsorption von 4′‐Diethylamino‐α‐cyanostilben‐4‐diazoniumionen durch Komplexbildung mit Ethylenglycolderivaten, Kronenethern und Valinomycin

Abstract

Colour Change of 4‐Diethylamino‐α‐cyano‐stilbene‐4‐diazonium Ions by Complex Formation with Ethylenglycol Derivatives, Crownethers and ValinomycineThe formation and light absorption of complexes consisting of coloured stilbene‐4‐diazonium ions and different ethylenglycoles, crownethers and valinomycine were investigated. On complex formation the longest wavelength absorption band of the diazonium compounds shifts hypsochromically. This hypsochromism is solvent dependent. The difference between the absorption maximum of a free and complexed diazonium ion increases with increasing polarity and decreasing n‐donicity of the solvents. Other complex forming cations are able to replace the diazonium ions in the complexes, whereby the colours of the original diazonium ions are regenerated. These colour changes can be used to indicate the ability of n‐donor compounds to act as an ionophore.

Stilbene and Azobenzene Diazonium Compounds as dye reagents for crown ethers

“…I n the presence of the crown ethers 6-10 the main band of the free or paired diazonium compounds disappear and the bands of the complexes are formed which lay always in the hypsochromic region of the former. Complexation is accompanied with a loss of extinction and a band broadening [2]. Only when the diazonium ion is paired with the anion the extinction increases.…”