某些不对称偶氮膦类新显色剂的合成及其与稀土元素显色反应的研究

某些不对称偶氮膦类新显色剂的合成及其与稀土元素显色反应的研究 SYNTHESIS OF SOME UNSYMMETRICAL BISAZO DERIVATIVE OF CHROMOTROPIC ACID CONTAINING=PO（OH） 2 AND SPECTROPHOTOMETRIC STUDIES ON COLOR REACTIONS WITH RARE EARTH ELEMENTS 张华山 first-author 陈震华 曾云鹗 < 正 > 变色酸双偶氮衍生物是一类重要的稀土显色剂,长期来用于稀土总量的测定,近年来其中某些发展成为稀土元素分组合量显色剂[1—6],目前对于这类试剂研究较多的是胂类、羧类、磺类,对不对称膦类研究的较少。在稀土测定中摩尔吸光系数大于10 5 以上的稀土总显色剂还没有,测定重稀土组份的显色剂选择性和灵敏度都不够理想,我们想以合成不对称膦类试剂出发,寻找出测定稀土总量和分量的选择性好、灵敏度高的显色剂。因为有些不对称的这类显色剂与稀土反应的灵敏度和选择性高于对称的,而且含有—PO 3 H 2 的这类显色含剂能在较强的酸性介质中与稀土反应,提高了选择性。不对称显色剂分子中,在不含 The amino-G acid chlorophosphonazo etc seven new spectrophotometric reagents have been synthesized. Color reactions of α-type and β-type of rare earths with these reagents and complex reactions in presence of cationic surface-active substance have been studied. In acidic media（pH1）these color reagents with rare earths form α-type complex immediately. The contrast is large（△λ > 120nm）. The sensitivity is high. In 0.1N HC1 solutiou molar absorption coefficient of α-type complex of Ⅰ,Ⅱ, Ⅲ, Ⅳ, Ⅴ and Ⅶ with La are 9.08×10 4 , 9.81×10 4 , 8.94×10 4 , 9.90×10 4 , 8.41×10 4 , and 5.17×10 4 ·l·cm -1 mol -1 at 677, 670, 676, 682, 669 and 682nm respectively. The calibration curve obey Beer’s law for 0-20μ 9/25ml rare earths elements. In optimum condition reagents Ⅰ-Ⅵ with yttrium-group rare earths can form β-type complex. The molar absorption coefficient of β-type complex of Ⅰ, Ⅱ, Ⅲ, Ⅳ, Ⅴ, and Ⅵ with yttrium are 7.38×10 4 , 12.47×10 4 , 3.92×10 4 , 5.91×10 4 8.47×10 4 and 3.36×10 4 ·l·cm -1 ·mol -1 at 730, 698, 719, 755 and 723nm respectively. Tendency of the coversion of chelates of yttrium is the largest. The corresponding chelates of lighter rare earths do not convert to β-type under the same condition, Heavier rare earths and yttrium can be determined in the presence of lighter rare earths. In presence of cationic surface-active substance（CTMAB, CPB, TPC etc）in acidic alcohol-water media, these reagents with lighter rare earths form high sensitivity ternary complex（ε > 10 5 ）. Under same condition the sensitivity of heavier rare earths is lower. 1982-03-01 2021-04-01 3