Fluorogenic ferrocenyl Schiff base for Zn and Cd detection.

A novel sensor based on acetylferrocene-containing Schiff base ( ASB) was synthesized by reaction of α-chloroacetylferrocene and N-(salicylidene)- l-valinmethylester. The structure of the compound was characterized by using elemental analysis and Fourier-transform infrared (FT-IR), H nuclear magnetic resonance (NMR), and C NMR spectroscopy. Its metal-cation-sensing properties were investigated spectrofluorometrically. ASB served as selective chemosensor for Zn and Cd towards alkali, alkaline-earth, and various heavy-metal ions. It showed significant fluorescence enhancement for Zn and Cd ions, stemming from C=N isomerization and chelation-enhanced fluorescence. The binding modes of the complexes were determined to have 1:1 complexation stoichiometry, and the binding constants were calculated as (6.93 ± 0.25) × 10 M for ASB· Zn and (7.49 ± 0.18) × 10 M for ASB· Cd using the nonlinear curve-fitting method. [ABSTRACT FROM AUTHOR]