Synthesis And Research Of Gas-sensing Properties Of Complexe With Sn（Ⅱ） And BipyO₂

In this article, the α,α’-bipyridine as starting material were oxidized by30%hydrogen peroxide, the product was characterized by IR and elemental analysis. Theresults showed that the product was2,2’-Bipyridine-1,1’-Dioxide（bipyO₂）. The metalcomplexes were obtained by mixed bipyO₂and stannous chloride in water andN,N’-dimethylformamide （DMF） respectively. The two products were the whitepowder. The products were characterized by IR and elemental analysis. The resultsshowed that the products obtained in two solution were the same substance, but theyelid in water was higher than that in DMF. The chemical formula of the complexescan be presumed to be Sn（bipyO₂）₂Cl₂by IR, Ultraviolet-visible spectroscopy,XRD powder diffraction, elemental analysis and each element’s ratio of quality incomplexes. Sn was the center atom in the complexes, bipyO₂and Cl^-were the ligands,the central atom’s coordination number was6. The complexes hada symmetrical molecular structure. The molar conductivity of complexe in water was246S cm²mol^-1, in DMF was approximately equal to0, indicated that thecomplexe is1:2type of electrolyte in water. With the DTA-TG analysis, thedecomposition temperature range of the complexes was375～378℃, andthe decomposition reaction was classified to exothermic reaction.A gas sensor was fabricated based on the complexes. the sensitive characteristicsof gas sensors were tested for inorganic gases and organic vapors, such asH₂S, SO₂, NO, NO₂, NH₃, Cl₂, formaldehyde, methanol, benzene, formaldehyde,ethanol, acetaldehyde, ethyl ether, vinyl acetate, chlorinated benzene, bromobenzene,chlorinated butane,chlorinated Chungbutane, chlorinated butyl,bromobutane, dichloromethane, chloroform, DMF, a diamine, ethylene diamine, with a static gas distributionand heated by test circuit in indirectly, The results showed that methanol made thesensor resistance change significantly only, indicated that the material hadgood sensitivity and selectivity to methanol （CH₃OH）. Made a further detailed studyon the test conditions, as well as the methanol concentration of the components of gas sensitivity. The measurement results showed that the gas sensor could detect theconcentration of methanol in the range of1.0～21.6×10^-2mmol/L. The best workvoltage was8V and the best work temperature range was15～40℃. The responsetime was155s, and the recovery time was12s. The stability tests showed that thesensor was stable and could be long-term repeated use.