Study On The Preparation And Fluorescence Of Fluorescent Material For Detection Of Volatile Organic Compounds

VOCs is an important pollutant in air, and more and more attention is paid to monitoring VOCs. At present, VOCs monitoring method is GC method, which needs complex sampling and pre-treatment, so the application of the method is restricted. Fluorescence analysis as an effective method to monitor VOCs attracts more and more attention. At present, the focus of fluorescence material study is to find new sensitive material for determination of VOCs. In this article, new materials which can monitor VOCs are reported and a preliminary study of the fluorescence property is performed. [Cu2I2(C9H7N)2]2 was prepared by reaction of copper(I) iodide with quinoline. Many VOCs, for example: acetone, butone, toluene, methanol, ethanol, n-hexylane, chloroform and ethylacetate, can quench fluorescence of [CuI3(C9H7N)]2 effectively. Ethanol, with increase of concentration, linearly quenches the fluorescence of [CuI3(C9H7N)]2. There is a remarkable difference between two XRD patterns of [CuI3(C9H7N)]2, one measured before the reaction of [CuI3(C9H7N)]2 with ethanol, and the other measured after the reaction. This change is supposed to be due to change of molecular structure of [CuI3(C9H7N)]2 powder caused by reaction of [CuI3(C9H7N)]2 with ethanol, which results in the quenching of [CuI3(C9H7N)]2. After the quenching of [CuI3(C9H7N)]2 fluorescence at 585 nm, a fluorescence peak at 500~550 nm was enhanced, which indicates the quenching at 585 nm is caused by energy transfer. N-decane was used to treat the production of [CuI3(C9H7N)]2 reacting with ethanol, then the fluorescence of [CuI3(C9H7N)]2 can comeback partly. Gas chromatography patterns of the n-decane confirmed the presence of ethanol, indicating that the product may incorporate ethanol into the crystal packing, and it is likely that this plays an important role in effecting the solid state isomerization. The crystal structure of complex [CuI3(C9H7N)]2 has been determined by four-circle diffraction. In the complex, one copper atom is co-ordinated by one nitrogen atom and three bridging iodine atoms, the other is co-ordinated by one nitrogen atom and two bridging iodine atoms. The steric repulsion effects crystal structure effectively. The adoption of the unusual three-cordination about the copper is ascribed to the steric crowding caused by the ligands. Compounds of different copper(I) halides reacting with quinoline were synthesized. There are some different fluorescence behaviors of the compounds, combining with different halides. With increase of the atomic number, the fluorescent emission peak moves to longer wavelength. While the product of copper(I) chloride react with quinoline does not exhibit fluorescence. In this article, a new important material which can be used to monitor VOCs by the quenching of [CuX3(C9H7N)]2 (X=I, Br) is reported.