Synthesis of dipicolylamino substituted quinazoline as chemosensor for cobalt(II) recognition based on excited-state intramolecular proton transfer.
A new fluorescent chemosensor for sensing Co(II) using di(2-picolyl)amino (DPA) as a recognition group and quinazoline as a reporting group has been synthesized and characterized. The quinazoline derivative contains an intramolecular hydrogen bond, which would undergo excited-state intramolecular proton transfer (ESIPT) at illumination. The fluorescence quenching is attributed to cation-induced inhibition of ESIPT, which constitutes the basis for the determination of Co(II) with the prepared chemosensor. The fluorophore forms 1:1 cobalt(II) complex with the logarithm of apparent dissociation constant log K(a)=6.8. The analytical performance characteristics of the proposed Co(II)-sensitive sensor were investigated. The chemosensor exhibits a linear response toward Co(II) in the concentration range 3.2 x 10(-8) to 1.4 x 10(-6) M, with a working pH range from 7.0 to 9.5 and high selectivity.
Luo
Hong-Yuan
HY
State Key Laboratory of Chemo/Biosensing and Chemometrics, College of Chemistry & Chemical Engineering, Hunan University, Changsha 410082, PR China.
Zhang
Xiao-Bing
XB
He
Chun-Lian
CL
Shen
Guo-Li
GL
Yu
Ru-Qin
RQ
D003035:Cobalt / Q000737:chemistry*; D006863:Hydrogen-Ion Concentration; D011522:Protons; D011799:Quinazolines / Q000138:chemical synthesis* / Q000737:chemistry*; D013050:Spectrometry, Fluorescence; D013056:Spectrophotometry, Ultraviolet
D011522:Protons; D011799:Quinazolines; D003035:Cobalt