Three-channel ferrocene-based chemosensors for Cu(II) and Hg(II) in aqueous environments

Ferrocene-based conjugated complexes, benzenediamine (A), benzidine (B) and disulfanediyldianiline (C) are synthesized and their spectroscopic, electrochemical and cation sensing properties are studied. Three complexes are high sensitive color systems for determination of Hg(II) and Cu(II) in DMSO-H2O (10:0.5) solution. The absorption spectral changes were observed upon the addition of either Hg(II) or Cu(II), with the dramatic naked eye detectable color changes from yellow to red or green respectively. Moreover, the addition of cations showed strong fluorescent quenching, while new redox peaks were observed during electrochemical titrations. The DFT calculations were carried out to investigate the electronic coupling between the ferrocene centers.