Metal ion-sensitive

In acid-base titrations the end point is generally detected by a pH-sensitive indicator. In the EDTA titration a metal ion-sensitive indicator (abbreviated, to metal indicator or metal-ion indicator) is often employed to detect changes of pM. Such indicators (which contain types of chelate groupings and generally possess resonance systems typical of dyestuffs) form complexes with specific metal ions, which differ in colour from the free indicator and produce a sudden colour change at the equivalence point. The end point of the titration can also be evaluated by other methods including potentiometric, amperometric, and spectrophotometric techniques. 

The most common design of metal ion sensitive probes involves changes in the coordination sphere of the Gdm ion following... 

Gupta, S., Paul, B. K., Barik, A. K., Mandal, T. N, Roy, S., Guchhait, N., Butcher, R. J., Kar, S. K (2009). Modulation of fluorescence emission of l-(2-pyridyl) pyrazole derived Schiff base ligands by exploiting their metal ion sensitive binding modes. Polyhedron, 28, pp.3577-3585, ISSN 0277-5387... 

Uses Biocide for aq formaldehyde, and bivalent metal ion-sensitive systems (wet state), paints/coatings, inks Acticide MBS Family [Thor UK]... 

Metal ion-sensitive protective groups Protection of amino groups as carbo-(8-quinoloxy)amines... 

Corey and Dawson have discussed the use of metal ion-sensitive protecting groups [149]. They find that the 8-quinolyloxy-carbonyl group is removed by brief treatment with copper or nickel salts in 50% aqueous acetone at 25°. The strong tendency of 8-quinolinol to chelate complex formation promotes cleavage under conditions where normal hydrolysis does not take place. The derivatives are easily prepared using the stable, crystalline bis(8-quinolinyl)carbonate in methylene chloride at 0°. 

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