Synthesis Of Bisazo Fluoroarsonoazo Reagents Of Asymmetric Chromotropic Acid And Its Application To The Spectral Analysis

The luminosity functions of bisazo arsonic acid reagents of unsymmetry chromotropic acid are used wiely in a good many fields,which are applied to determination of rare earth and non-rare earth.In the thesis, 20 new asymmetrical bisazo arsonic acid reagents of chromotropic acid have been designed and synthesized.All the reagents are prepared following this route.lt begined with p-flourozniline through acetylation protected in acetic acid with acetic anhydride, nitration, de-aethlation, diazotization, arsonations and reduction, couping with chromotropic acid,then obtained 5-FAsA- I .The destination products can be got through the way of having the 5-FAsA- I couple with other substituted anilines derivatives in different conditions .Of all the procedures,the preparation of important intermediates-arsonic acid compound and the diazo couping reaction are key to the synthesis of these reagents. A good methord was used to synthesize 2-nitro-4-fluorobezene arsonic acid in higher yield and better quality compared with those that reported.In the meantime, the different couping reactional conditions according to the different compounds structures were studied and discussed.The spectrophotometic behaviors of 20 color reagents with earth rare(Ce,Y) and bismuth have been described.The absorption curves, acidmedium and acidity conditions,amount of color reagents,surface active agents and organic solvents,the allowable amount of common interfering ions were defined. Most of reagents react with metal ions immediately and have high sensitivity,large contrast and good stability. The results showed that - these reagents with three auochromes such as 5-FAsA-DBK, 5-FAsA-DBN, 5-FAsA-TC have high sensitivity and excellent selectivity.Rules are summarized about the relations between the structures and the color reactions.The chromogenic ractions of 5-FAsA-DBN with rare earth,thorium and bismuth has been studied in detail.The complexes of rare earths with the reagents have maximum absorption at about 628nm and the apparent molar absorption are ε Ce=1.29×103 L·mol-1·cm-1 and ε Y= 1.29×105L·mol-1·cm-1. Beer's law is obeyed for rare earth in the range of 0-25ug/25ml. The apparent molar absorptivities of the other two complexesare ε Th=1.33×105L·mol-1cm-1 and ε Bi=1.23×105 L·mol-1·cm-1 reapectively, Beer's law is obeyed for Th(IV) in the range of 0-26ug/25ml and for Bi(III) 0-35ug/25ml.This methord has been used to determination trace Ce(III) in noular cast iron and Bi(III) in compound bismuth aiuminate tablets with satisfactory results. So is the chromogenic ractions of 5-FAsA-DBK with cerium-group rare earth.