A new half-condensed Schiff base platform: structures and sensing of Zn 2+ and H 2 PO 4 - ions in an aqueous medium.

A newly designed and synthesized half-condensed organic moiety 2-hydroxy-5-methyl-3-[(2-phenylamino-phenylimino)-methyl]-benzaldehyde (HL ') and aZn(2)L(4)complex sequentially detect Zn(2+)and H(2)PO(4)(-)ions as low as 1.13 nM and1.23 mu M, respectively.HL ' and a dinuclear Zn(ii) complex ofin situgeneratedL(-)in a solution formulated asZn(2)L(4)under investigation were characterized by physicochemical and spectroscopic studies along with detailed structural analyses by single-crystal X-ray crystallography. The selectivity and sensitivity ofHL ' towards Zn(2+)ions and of theZn(2)L(4)complex towards H(2)PO(4)(-)ions are based on CHEF andviadisplacement pathways, respectively. Dual sensing of Zn(2+)ions and H(2)PO(4)(-)ions in an aqueous mediumvia "Green-Blue-Green" emission with the reversible transformation ofin situformedHL ' toHLwas established by detailed electronic absorption and emission spectroscopic studies. This non-cytotoxic probe (HL ',i.e.producedHLin solution) andZn(2)L(4)complexes are able to monitor the subcellular distribution changes of Zn(2+)and H(2)PO(4)(-)ions, respectively, by fluorescence microscopy using the human semen sample.