Ultraviolet Spectrum And Infrared Probe Analysis Of Tetrafluoroborate Ionic Liquid

Environmentally friendly ILs have emerged as neoteric solvents with special properties and behaviors.Desirable products with high yields and reduced amounts of wastes can be obtained without uses of special apparatuses or methodologies by choosing the appropri-ate ILs.Moreover,ILs can be recycled,thus leading to lower processing costs.While the application of ILs has been seen in almost every aspect of science and industry,the field is still in its infancy,and is therefore far from mature for many commercial applications.As such,the study of ILs has lately become a major focus of academic as well as industrial research.All in all,it is expected that further developments and researches should be undertaken in the coming future for the ultimate deployment of ILs.The qualitative analysis of HP-BF₄ were characterized by UV absorption spectra in the solution of acetonitrile,methanol,deionized water and ethanol.the results showed that the UV spectra of HP-BF₄ ionic liquid can receive the effect of solvent polarity will also receive the influence of pH value of the solution.The quantitative analyses of ionic liquid ofHP-BF₄ were measured in Acetonitrile,methanol,deionized water and ethanol.UV absorption spectrum curve were obtained.The standard curve was plotted at the maximum absorbance values.Lonic liquids spiked recoveries were obtained by standard addition.The measured values were better,so the quantitative analysis of seven ionic liquids can be measured by UV.The experiment using pyridine as probe to detect the acidity of ionic liquids system.The results show that the acid type and acid strength of the ionic liquid can be measured well.The application of pyridine probe infrared spectroscopy can not only determine the acid type ionic liquid（Br nsted/Lewis acid）,but also simple determination of the acid strength of the ionic liquid.With the increasing of the mole fraction of AlCl3 in ionic liquids,the acidity of ionic liquids is enhanced.Acetonitrile was used as a probe to detect the acidity of ionic liquids.The results obtained by using the acetonitrile probe method for the determination of the acidity of ionic liquids are in agreement with the results obtained by the pyridine probe method.The two methods can be used to determine the acid type and acid strength of ionic liquids.The results showed that acid type ionic liquid acetonitrile can be determined,when having Lewis acidic liquid,there will be a new absorption peak,with Br nsted diameter acidic liquid,its absorption peak will only lead to larger wave numbers,and the peak does not change.At the same time,we found that with the increase of xAlCl3 value,the ionic liquid moves toward the high wave number and the acidity increases.Experiments through the common fluorescent agent alizarin red（ARS）and alkyl pyridine substances in the chemical reaction,resulting in complexes,thereby changing the fluorescence properties of alizarin red.In the experiment,we observed the change of fluorescence intensity by observing the reaction of alizarin red with the alkyl chain.It was found that the length of the alkyl chain affected the quenching of alizarin red.Also,the concentration of ionic liquids also affects the quenching of alizarin red.The results show that there is no linear relationship between the fluorescence fluorescence quenching and the concentration of pyridine salt ions when the alkyl chain is short.When the alkyl chain is long,the fluorescence quenching increases with the increase of the alkyl chain The While the concentration of ionic liquids is inversely proportional to the quenching intensity.