Novel selective and sensitive optical chemosensor based on phenylfluorone derivative for detection of Ge(IV) ion in aqueous solution

作者：Keawwangchai Somchai; Morakot Nongnit; Keawwangchai Tasawan^*

来源：Spectrochimica Acta Part A: Molecular and Biomolecular Spectroscopy , 2018, 202: 290-300.

DOI：10.1016/j.saa.2018.05.063

• Phenylfluorone
• Naked-eye
• Chemosensor
• Germanium(IV)
• DET/LanL2DZ

A water soluble chemosensor for Ge4+ ion based on fluorone derivative containing 3,4-bis(2-(diethylamino) -2-oxoethoxy)phenyl (R8) has been synthesized. The binding abilities between R8 and 10 equiv. of Na+, K+ Ca2+, Fe2+, Cu2+, Cd2+, Hg2+, Pb2+, Al3+, Cr3+, Fe3+ and Ge4+ ions in 1% v/v EtOH-water (tris-buffer pH 7.0) were studied using UV-vis and fluorescence spectrophotometry. When observed by naked-eyes, the color of R8 changed from yellow-orange to pink and the fluorescent color changed from green to non-fluorescence when complexed with Ge4+ ion. The spectral analysis showed that UV-vis absorption and fluorescence emission intensity of R8 decreased dramatically when Ge4+ ion was added comparing with other ions. To explain this behavior, the quantum calculation was performed using the hybrid density functional at B3LYP/LanL2DZ level of theory. The calculated orbital energies indicated that the decreasing of UV-vis absorption and the quenching of fluorescence were due to the complexation induced metal to ligand charge transfer. The association constants (K-a) of R8-Ge4+ complexes calculated from Benesi-Hildebrand equation was 6.21 x 10(5) M-1. The UV-vis detection limit for Ge4+ was 4.40 x 10(-7) M which was three orders of magnitude lower than those of Al3+, Cd2+, Cu2+ and Na+ ion.

• 出版日期2018-9-5