文摘
A multisensor which is based on a novel multifunctional triad molecule, ferrocenyl naphthoquinone fused crown ether (Fc鈥揷nq) bearing ferrocene, quinone, and crown ether functional groups together, was synthesized and characterized in this study. Sensing performance of a trace amount of water and the selective cation binding capabilities of this multisensor were carried out by the electrochemical, spectroelectrochemical, and spectrophotometric titration techniques in acetonitrile (CH3CN). It was shown that the potential separation (E(Fc)1/2 鈥?E(2)1/2) between the second reduction of naphthoquinone and the oxidation processes of ferrocene in the triad molecule Fc鈥揷nq was proportional to the amount of water due to the hydrogen-bonding interactions between water and the doubly reduced species (Fc鈥揷nq2鈥?/sup>). This property enabled Fc鈥揷nq to detect the trace amount of water in CH3CN. The half-wave potential (E(Fc)1/2) of the ferrocene in Fc鈥揷nq was used as an internal reference potential, and it defined the accuracy of the detection. In addition, by using the UV鈥搗is spectrophotometric titration technique in CH3CN, it was also shown that the Fc鈥揷nq multisensor could bind Ba2+ and Ca2+ cations selectively. We proposed that the intramolecular charge-transfer (CT) transition which occurred between the donor ferrocene and the acceptor naphthoquinone was the principle mechanism for the selective binding property of this multisensor. Quantum chemical calculations were also performed to investigate optical and electronic properties of the Fc鈥揷nq molecule.