A new, simple, precise, selective and sensitive method for the extraction and spectrophotometric determination of niobium has been described. Mixed-ligand complexes of Niobium (V) with 2,6-dithiolphenol (DTP) and amin...A new, simple, precise, selective and sensitive method for the extraction and spectrophotometric determination of niobium has been described. Mixed-ligand complexes of Niobium (V) with 2,6-dithiolphenol (DTP) and aminophenols (AP) have been studied by spectrophotometry. Extraction of mixed-ligand complexes is maximal at pH 3.6 - 5.0. The optimal conditions for the formation and extraction of mixed-ligand compounds have been found. The molar ratio of the reacting species was 1:2:2 (Nb:DTP:AP). The Beer’s law was applicable in the range of 0.05 - 4.0 μg/ml. The method is free from common interferences. A procedure has been developed for extraction-spectrophotometric determination of Niobium in steel.展开更多
The FT-IR spectra for K_2NbF_7-FLINAK-O^(2-) solution were measured and compared with the spectra of crystalline K_2NbF_7 and K_2NbOF_6.The results show that the niobium fluoro-complex and/or oxyfluoro-complex ions ar...The FT-IR spectra for K_2NbF_7-FLINAK-O^(2-) solution were measured and compared with the spectra of crystalline K_2NbF_7 and K_2NbOF_6.The results show that the niobium fluoro-complex and/or oxyfluoro-complex ions are presented in these solutions.NbF_7^(2-) complex ion is the predominant species in Nb(V)-FLINAK solution(not considering oxide impurity).The influence of O^(2-) on the oxyfluoro-complex ions shows that NbOF_6^(3-) as a stable monooxyfluoro-complex anion presented in FLINAK-O^(2-) systems and the number of NbOF_6^(3-) species are increased with increasing of O^(2-) when molar ratio of O^(2-)/Nb(V) is less than 1.展开更多
文摘A new, simple, precise, selective and sensitive method for the extraction and spectrophotometric determination of niobium has been described. Mixed-ligand complexes of Niobium (V) with 2,6-dithiolphenol (DTP) and aminophenols (AP) have been studied by spectrophotometry. Extraction of mixed-ligand complexes is maximal at pH 3.6 - 5.0. The optimal conditions for the formation and extraction of mixed-ligand compounds have been found. The molar ratio of the reacting species was 1:2:2 (Nb:DTP:AP). The Beer’s law was applicable in the range of 0.05 - 4.0 μg/ml. The method is free from common interferences. A procedure has been developed for extraction-spectrophotometric determination of Niobium in steel.
文摘The FT-IR spectra for K_2NbF_7-FLINAK-O^(2-) solution were measured and compared with the spectra of crystalline K_2NbF_7 and K_2NbOF_6.The results show that the niobium fluoro-complex and/or oxyfluoro-complex ions are presented in these solutions.NbF_7^(2-) complex ion is the predominant species in Nb(V)-FLINAK solution(not considering oxide impurity).The influence of O^(2-) on the oxyfluoro-complex ions shows that NbOF_6^(3-) as a stable monooxyfluoro-complex anion presented in FLINAK-O^(2-) systems and the number of NbOF_6^(3-) species are increased with increasing of O^(2-) when molar ratio of O^(2-)/Nb(V) is less than 1.
