Synthesis of 1-Acetyl-3-(2-hydroxyl-4,6-dimethoxyphenyl)-5-aryl-2-pyrazoline and Their Applications as Fluorescent Sensors for Cu~(2+)

Copper plays an important role in various physiologic processes.The design and synthesis of chemosensors for copper ions has become a very active area of research.The synthetic Cu2+ selective fluoroionophores so far reported suffer from low sensitivity and,in general,higher concentrations of interfering metal ions disturb the selectivity towards Cu2+.Here we report the synthesis of six 1-acetyl-3-(2-hydroxyl-4,6-dimethoxylphenyl)-5-aryl-2-pyrazoline(4a—4f) and the studies of them as fluorescent sensors for Cu2+ ion.The structures of all the products were determined by IR,MS,1H NMR and elemental analysis.Their UV and fluorescence spectra were measured.The influences of eight metal ions such as Cu2+,Zn2+,Ni2+,Co2+,Na+,Al3+,Cd2+,Ca2+ and Mn2+on their fluorescence properties were studied.Spectroscopic studies revealed that the compounds 4a—4f had rather strong affinity toward Cu2+.The specificity of the probes 4f toward Cu2+ were determined.Nearly no fluorescence intensity changes were observed in emission spectra with Zn2+,Ni2+,Co2+,Na+,Al3+,Cd2+,Ca2+ and Mn2+.However,under identical conditions,the results showed fluorescence quenching with Cu2+.So we have developed an new fluorescent sensor 4f.It shows high sensitivity and selectivity toward Cu2+ in DMSO.