Study of Derivatives of 2,6 -Diaminopyridine as Fluorescence Probe of Transition Metal Ions
ZHOU Yan-mei1,TONG Ai-jun2
1. School of Chemistry and Chemical Engineering, Henan University, Kaifeng 475001, China 2. Department of Chemistry, Tsinghua University, Beijing 100084, China
Abstract：Three derivatives of 2,6-diaminopyridine were synthesized with naphthyridine ring and —NH2,—OH and —NHCOCHCH2 groups. They are 2,4-dimethyl-7-hydroxyl-1,8-naphthyridine (DMHND), 2,4-Dimethyl-7-amino-1,8-naphthyridine (DMAND ) and DMAAN. The binding ability of the derivatives of 2,6-diaminopyridine for metal ions in acetonitrile was investigated using UV-Vis and fluorescence spectrometry. The changes of the dyes spectra were observed in the presence of transition metal ions, but were not observed in the presence of K+,Na+,Mg2+,Ca2+ and Pd2+. Except for DMHND that has weak binding ability for Cu2+,two dyes can bind with Cu2+ at the ratios of DMAAN∶Cu2+=1∶1, DMAND∶Cu2+=1∶1. The resulting binding curves were analyzed by nonlinear regression methods, giving the association constant for DMAAN to be about 4.4×105 L·mol-１,and about 6.3×106 L·mol-１ for DMAND. DMAND contains an electron-donating group (amino group) conjugated to an electron-withdrawing group (the pyridine ring), and undergoes intramolecular charge transfer from the donor to the acceptor upon excitation by light. When Cu2+ interacting with the N of the pyridine ring enhances the electron-withdrawing character of this group, the spectrum is thus red-shifted and the intensity is increased. DMAND displayed a high sensitivity among the three derivatives of 2,6-diaminopyridine as the fluorescence probe of transition metal ions.
Key words：Fluorescent probe;Transition metal ions;2;6-diaminopyridine
周艳梅1,童爱军2. 2,6-二氨基吡啶衍生物作为过渡金属离子荧光探针的研究[J]. 光谱学与光谱分析, 2007, 27(12): 2518-2522.
ZHOU Yan-mei1,TONG Ai-jun2. Study of Derivatives of 2,6 -Diaminopyridine as Fluorescence Probe of Transition Metal Ions. SPECTROSCOPY AND SPECTRAL ANALYSIS, 2007, 27(12): 2518-2522.
