title: A highly selective on/off fluorescence sensor for cadmium(II).
abstract: A polypyridyl ligand, 2,3,6,7,10,11-hexakis(2-pyridyl)dipyrazino[2,3-f:2',3'-h]quinoxaline (HPDQ), was found to have excellent fluorescent selectivity for Cd(2+) over many other metal ions (K(+), Na(+), Ca(2+), Mg(2+), Mn(2+), Fe(2+), Ni(2+), Co(2+), Cu(2+), Ag(+), Hg(2+), Zn(2+), and Cr(3+)) based on the intramolecular charge-transfer mechanism, which makes HPDQ a potential fluorescence sensor or probe for Cd(2+). An obvious color change between HPDQ and HPDQ + Cd(2+) can be visually observed by the naked eye. The structure of the complex HPDQ-Cd has been characterized by X-ray crystallography. Density functional theory calculation results on the HPDQ and HPDQ-Cd complexes could explain the experimental results.
authors: Department of Chemistry and Tianjin Key Lab on Metal and Molecule-based Material Chemistry, Nankai University, Tianjin 300071, China.
authors: Qiang
authors: Q
authors: Zhao
authors: Rui-Fang
authors: RF
authors: Li
authors: Sheng-Kai
authors: SK
authors: Xing
authors: Xiu-Ming
authors: XM
authors: Liu
authors: Tong-Liang
authors: TL
authors: Hu
authors: Xian-He
authors: XH
authors: Bu