title: Synthesis of dipicolylamino substituted quinazoline as chemosensor for cobalt(II) recognition based on excited-state intramolecular proton transfer.
abstract: 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.
authors.affiliation: State Key Laboratory of Chemo/Biosensing and Chemometrics, College of Chemistry & Chemical Engineering, Hunan University, Changsha 410082, PR China.
authors.forename: Hong-Yuan
authors.initials: HY
authors.lastname: Luo
authors.forename: Xiao-Bing
authors.initials: XB
authors.lastname: Zhang
authors.forename: Chun-Lian
authors.initials: CL
authors.lastname: He
authors.forename: Guo-Li
authors.initials: GL
authors.lastname: Shen
authors.forename: Ru-Qin
authors.initials: RQ
authors.lastname: Yu
mesh_terms: D003035:Cobalt / Q000737:chemistry*; D006863:Hydrogen-Ion Concentration; D011522:Protons; D011799:Quinazolines / Q000138:chemical synthesis* / Q000737:chemistry*; D013050:Spectrometry, Fluorescence; D013056:Spectrophotometry, Ultraviolet
chemical_list: D011522:Protons; D011799:Quinazolines; D003035:Cobalt