The conditions of colour reaction of 2-(1,3,4-Triazolylazo)-5-Diethylamino-benzoic acid(TZDBA)with vanadium(V) are presented.The results show that the colour reagent reacts with vanadium,and forms a stable purple red ...The conditions of colour reaction of 2-(1,3,4-Triazolylazo)-5-Diethylamino-benzoic acid(TZDBA)with vanadium(V) are presented.The results show that the colour reagent reacts with vanadium,and forms a stable purple red complex in the medium of HCl with pH 2.0. The apparent molar absorptivity is 3 17×10 4L·mol -1 ·cm -1 ,and the maximum absorption wavelength is at 571 nm.Beer’s law is obeyed in the range of 0～20 μ g/25ml for V(V).The method has been used for the direct determination of vanadium in a aluminium alloy sample and a synthetic water sample with satisfactory results.展开更多
A nanosolid heteropoly acid of H 3PW 12 O 40 /SiO 2 was prepared with the sol-gel method and used to catalyze sythesis of methyl 5-amino-1,2,4,-trazolylformate sulfate.The structure of the nanosolid heteropoly acid H ...A nanosolid heteropoly acid of H 3PW 12 O 40 /SiO 2 was prepared with the sol-gel method and used to catalyze sythesis of methyl 5-amino-1,2,4,-trazolylformate sulfate.The structure of the nanosolid heteropoly acid H 3PW 12 O 40 /SiO 2 was characterized by IR,XRD and TEM.The following optimum condition were that the mole ratio of alcohol to carboxylic acid is 27∶1,the temperature is 75℃,the reaction time is 5 hours,and the catalyst is 2 5% of feedstock.Under the optimum conditions,the yield of esters was above 94%.展开更多
文摘The conditions of colour reaction of 2-(1,3,4-Triazolylazo)-5-Diethylamino-benzoic acid(TZDBA)with vanadium(V) are presented.The results show that the colour reagent reacts with vanadium,and forms a stable purple red complex in the medium of HCl with pH 2.0. The apparent molar absorptivity is 3 17×10 4L·mol -1 ·cm -1 ,and the maximum absorption wavelength is at 571 nm.Beer’s law is obeyed in the range of 0～20 μ g/25ml for V(V).The method has been used for the direct determination of vanadium in a aluminium alloy sample and a synthetic water sample with satisfactory results.
文摘A nanosolid heteropoly acid of H 3PW 12 O 40 /SiO 2 was prepared with the sol-gel method and used to catalyze sythesis of methyl 5-amino-1,2,4,-trazolylformate sulfate.The structure of the nanosolid heteropoly acid H 3PW 12 O 40 /SiO 2 was characterized by IR,XRD and TEM.The following optimum condition were that the mole ratio of alcohol to carboxylic acid is 27∶1,the temperature is 75℃,the reaction time is 5 hours,and the catalyst is 2 5% of feedstock.Under the optimum conditions,the yield of esters was above 94%.
