Snthesis Of Bisazo Fluoroarsenazo Reagents Of Chromotropic Acid And Their Color Reaction With Thoriumy

After the syntheses of arsenazo III, Bisazo arsenazo reagents of asymmetric chromotropic Acid have shown their excellent luminosity function in determination of both rare earth metals and other metals such as bismuth, thorium etc .so they are used widely in many fields . In consideration of the extraordinary chemical property of fluorine ,the author introduce fluorine atom into the reagents molecule ,so 23 new Bisazo arsenazo Reagents of Asymmetric Chromotropic Acid are designed and synthesised ,and few of them have been reported by now .Their molecular structures are as follows:After reading all the available literature ,all the reagents are synthesised beginning with p-flouoroaniline through acetylation , nitration , hydrolysis , arsonation , disoxidation , coupling with Chromotropic Acid and then coupling with all kinds of aromatic amine .Every procedure of this article are all light-duty tests with high yields ,and they can been designed easily for the production of chemical industry .We find most of the reagents , which are purified by acid and alkali , can been used directly to determine thorium. Bisazo arsenazo reagents of Asymmetric chromotropic Acid are also excellent reagents in determination rare earth metals and bismuth , but the author did the researches especially on the luminosity function of these reagents with thorium . Thus the absorption curves , acid medium and acidity conditions , the amount of reagents , the affects of surface active agents and organic solvents , and the allowable amounts of common interfering ions are found , the author figure out the molar absorptivities , and with these data , we find some regularities between the structures and the photometric characters of the reagents.In this thesis , the colour reactions between all of the reagents and thorium are studied , though some of them can not been used in practice , due to the introduction ofthe strong electrophilic fluorine atom into the reagents molecule, most of them are excellent in determination thorium, for example , their molar absorptivities are as high as 7.19~ 16.9 104 L mol-1 cm-1, the systems of each reagents and thorium can been kept for at least 24 hours with little changes , Beer's law holds in wide ranges , the selectivity of thereactions are also excellent and so on . Among them , 5-FAsA-III, fluorarsenazo-III, difluorarsenazo-III and 5-FAsA-DBF are the best ones .their sensitivity of the reactions are ashigh as 15.6, 15.9, 16.9 and 16.3 104 L mol-1 cm-1, when they are used to determine thorium, they not only allow several milligram general metal ions' existence (for example Cu2+, Fe3+, Mg2+, Ca2+, K+, Co2+, Zn2+ and soon ) but also allow rare earth ions' and bismuth ion's existence .In a word, they show better excellent luminosity function in determination than many other reagents.In the end, some reagents with excellent luminosity function are applied to determine thorium in sea food sample with satisfactory results .