Preparation of fluoroionophores based on diamine-salicylaldehyde derivatives

We have developed a series of fluoroionophores from diamine-salicylaldehyde (DS) derivatives and studied their spectra diversity when interacting with a variety of metal cations. Based on our results, 2-((E)-(2-(dimethylamino)ethylimino)methyl)-4-(4-methoxystyryl)phenol (I) can specifically chelate Zn+2 in both organic and semi-aqueous solution. Furthermore, 2-((E)-(2-(dimethylamino)ethylimino)methyl)-4-((E)-2-(pyridin-4-yl)vinyl)-phenol (II) is an excellent metal recognizer, successfully identifying Zn+2 from acetates, chloride and perchlorate salts. In addition, control compound (E)-N-(2-methoxy-5-((E)-2-(pyridin-4-yl)vinyl)benzylidene)-N′,N′-dimethyl-ethane-1,2-diamine (IV) also showed specific metal response to Cd+2 from Cd(OAc)2 over other anions. This anionic-dependent metal binding behavior was imparted by the pyridine moiety, which supports extra intermolecular metal-fluorophore complexation. Fluoroionophores I and II were preliminarily tested for cellular metal staining in general fluorescence and ratio fluorescence methods.

4-Vinylpyridine conjugated Diamine-Salicylaldehyde (fluoroionophore II) is not only an excellent metal recognizer, successfully identifying Zn+2 from acetates, chloride and perchlorate salts, but also have possible applications in physiological diagnosis.Figure optionsDownload as PowerPoint slideHighlights
► We developed a theoretical platform for fluoroionophore screening.
► The theoretical logic is established using the ESIPT and ICT effects.
► This screening platform is useful under organic and/or semi-aqueous conditions.
► Some fluoroionophores successfully recognized metal in cells.