title: C2-symmetrical hexaazatriphenylene derivatives as colorimetric and ratiometric fluorescence chemsensors for Zn2+.
abstract: Two C2-symmetrical hexaazatriphenylene (HAT) derivatives, 2,3-diphenyl-6,7,10,11-tetra(pyridin-2-yl)dipyrazino[2,3-f:2',3'-h]quinoxaline (1) and 2,3,6,7-tetraphenyl-10,11-di(pyridin-2-yl)dipyrazino[2,3-f:2',3'-h]quinoxaline (2), were designed and synthesized by the condensation reaction of 1,2-diamines and 1,2-diketones. Both compounds 1 and 2 exhibit sensitive, ratiometric and colorimetric fluorescence selectivity for Zn(2+) ion over alkali ions, alkaline earth ions and a wide range of transition metal ions upon excitation at 350 nm in acetonitrile/water. The interactions between 1 or 2 and Zn(2+) can be observed by naked eyes with an obvious color change of the solution from colorless to yellow. For fluorescence intensity of 2 toward Zn(2+), a good linearity (correlation coefficient R(2)=0.993) was established with a detection limit of 0.095 μM, which is more sensitive than that of 1 (0.2 μM). The binding modes of the free ligands 1 and 2 with Zn(2+) are discussed in context to their photophysical and electrochemical properties as well as single X-ray crystallographic structures of 1, 2 and 1-Zn.
authors.affiliation: Department of Chemistry and Tianjin Key Laboratory on Metal and Molecule-based Material Chemistry, Nankai University, No. 94, Weijin Road, Tianjin 300071, PR China.
authors.forename: Xiao-Hong
authors.initials: XH
authors.lastname: Zhang
authors.forename: Qiang
authors.initials: Q
authors.lastname: Zhao
authors.forename: Xiu-Ming
authors.initials: XM
authors.lastname: Liu
authors.forename: Tong-Liang
authors.initials: TL
authors.lastname: Hu
authors.forename: Jie
authors.initials: J
authors.lastname: Han
authors.forename: Wen-Juan
authors.initials: WJ
authors.lastname: Ruan
authors.forename: Xian-He
authors.initials: XH
authors.lastname: Bu
mesh_terms: D003124:Colorimetry; D003460:Crystallization; D005453:Fluorescence; D009281:Naphthalenes / Q000737:chemistry*; D013050:Spectrometry, Fluorescence; D014961:X-Ray Diffraction; D015032:Zinc / Q000032:analysis*
chemical_list: D009281:Naphthalenes; C547330:hexaazatrinaphthylene; D015032:Zinc