钪与茜素磺酸纳形成络合物的组成与稳定性的研究

SPECTROPHOTOMETRIC STUDIES IN THE COMPOSITION AND STABILITY OF SCANDIUM AND ALIZARIN SULPHONATE COMPLEX

本文研究了钪与茜素磺酸纳成成络合物的条件,组成和稳定性。认为钪可以在较低的pH(例如1.5)与茜素磺酸钠形成络合物,络合物的颜色随着pH之增大而加深,可以自橘红色转成深紫色。钪与茜素磺酸钠所形成络合物的显色时间在10分钟内已达到最高峯,此后在一小时内光密度几乎保持不变。应用Ostromisslensky和Job等克分子浓比递变法和不等克分子浓比递变法,分别在520mμ及540mμ两种不同波长,测其光密度,测定结果认为在不同pH下,钪与茜素磺酸钠只形成一种络合物,这络合物的祖成,卽钪与茜素磺酸钠的此例应为1:1。测定了钪与茜秦磺酸钠络合物的形成常数K_f値,log K_f在25℃计算的结果应为4.634±0.30。其生成吉氏函数△Z^0应为-6.29±0.41千卡。

Formation of a pink colored complex by the interaction of Sc (Ⅲ)and sodium alizarin-3-sulphonate has been reported. The chelate has maximum abrorption at 540 mμ. The composition was determined by Ostromisslensky and Job's method of con- tinued variation. Measurements using both equimolecular and non-equimolecular solu- tion were done at two different wave lengths, viz, 520 and 540 mμ by spectrophoto- metric meassurements. The composition is indicated 1:1. The chelate is stable between pH 1.5-11.5. The stability has been determined and the values of log K_f and △Z^0 work out respectively to be 4.634±0.30 and -6.29±0.41 K-cal. at 25℃.