Synthesis and characterization of a new fluorescent molecule for selective determination of transition metal ions

In this work, by elucidating photophysical properties of organically modified silane molecule (AqI) which was synthesised as a product of reaction between 3-aminoquinoline and isocyanatopropyltriethoxysilane, interaction of AqI with metal ions and the stoichiometry of complex formed was analyzed with spectrophotometric methods. Synthesised AqI molecule was characterized with FTIR spectroscopy. When investigated in different ethanol-water mixtures, the most emission change related to interaction between AqI and mercury (II) was observed in ethanol-water 1:4, v/v. By using spectra obtained from Uv-vis and fluorescence measurements, quantum yield of AqI in different solvents was calculated. Interaction between AqI and metal ions was analyzed with fluorometric titration. In different ethanol-water mixtures, by using fluoresence intensity of AqI in presence and absence of mercury (II) ions, suitable solution mixture for sensing of mercury (II) ion was determined. By investigating effect of pH on complex formation between AqI and Hg2+ ions, pH range which complex is stable was elucidated. Equilibrium constant of complex between AqI and mercury (II) ions was determined. Photophysical behavior of AqI in solvents with different polarity, was determined in relation with polarity and dielectric constants of solution. Interference effect of other metals in determining mercury(II) ions was tested by adding other metal ions to the solution of AqI in presence of mercury (II) ions. By using EDTA which has the ability of forming a complex with mercury (II) ions and blocking formation of complex between AqI and mercury (II), the renewability feature of sensor system was searched and reusability conditions were investigated.