基于欧原醇衍生性染料的新型阳离子传感器

The reaction of weakly electrophilic aryldiazonium (also called arenediazonium) salts with highly activated aromatic compounds leads to the formation of products with an —N=N— link, called an azo linkage. This reaction, presented in Figure 1, is known as diazo coupling and occurs without the loss of the nitrogen atoms of the aryldiazonium salt. Highly activated aromatic compounds such as phenols or arylamines favor the diazo coupling reaction. The coupling generally occurs at the...

Different methods, such as visual observance of metal-ion indicators, spectroscopic techniques, and potentiometric methods, can determine the endpoint of an EDTA titration.
In the visual method, metal-ion indicators (metallochromic dyes), which have distinct colors in their free and complex forms, are added to the mixture to signal the titration's end point. They form stable complexes with metal ions, but these complexes are weaker than the corresponding metal–EDTA complexes. As a...

Complexometric titration involves the formation of a complex by reacting a metal ion with one or more ligands. A visual indicator often detects the end point of a complexometric titration. It is added to the metal solution before the titration, forming a stable metal–indicator complex and imparting color to the solution. As the titration approaches the equivalence point, the excess of the added ligand displaces the indicator from the metal–indicator complex, releasing the free...