Zincke reaction in the synthesis of novel glutaconaldehyde derivatives: Synthesis of potassium 2,10-diamino-1,1,3,9,11,11-hexacyanoundeca-2,4,6,8,10-pentaen-1-ide and its application for fluorimetric quantitative determination of Fe3+ ions

Abstract

Under the conditions of a modified “one-pot” Zincke reaction, novel aza-merocyanines based on the dimer of malononitrile, pyridine, and α-iodonicotinonitrile derivatives were synthesized. It was demonstrated that in the presence of weak bases, the solutions of the obtained compounds exhibit fluorescence with λ_max^em around 660 nm, accompanied by a color change from pale yellow to violet. Interaction of these aza-merocyanines with the potassium salt of the malononitrile dimer yielded a new glutaconaldehyde derivative, which can be used for the quantitative fluorimetric determination of Fe³⁺ ions at low concentrations.