对乙酰基偶氮羧与轻重稀土元素共显色现象的研究

对乙酰基偶氮羧与轻重稀土元素共显色现象的研究 A STUDY ON THE COCOLORATION EFFECT FOR THE CARBOXYLACETYLAZO WITH LIGHTER AND HEAVIER RARE EARTHS 张长寿 first-author 罗庆尧 余席茂 曾云鹗 <正> 变色酸双偶氮羧酸型试剂与稀土元素反应中的共显色现象,最初发现于偶氮硝羧[1-4],目前,关于这一现象的研究尚不深入。主要有两种观点,一种观点认为偶氮硝羧与轻重稀土的共显色是由于形成了异核（轻稀土和重稀土）多元络合物所致[5-6];另一种观点认为此类共显色现象可能是由于浓度的改变而提高了重稀土显色速度的缘故[7]。我们在研究一系列变色酸双偶氮羧酸型试剂与稀土元素的显色反应中,发现当羧基（—COOH）位于一侧偶氮基（—N=N—）的邻位时,试剂与稀土元素具有分组显色的特性,并且都出现了共显色现象。为了探讨这一现象的本质,我们以对乙酰基偶氮羧为例,对这一试剂与稀土元素反应中的共显色现象进行了比较深入的研究。 In this paper, on the cocoloration effect of the Carboxylacetylazo with lighter and heavier rare earths is studied in detail. It shows the rate of color of the mono-heavier （Yb） increases with increasing concentration of Yb and color reagent, and with increasing pH. The value for eocoloration （AA） is depend upon the concentration of La and Yb: When the concertration of La in the constant value, AA increases with increasing the concentration of Yb, and with increasing the concentration of La when the concentration of Yb is fixed. A mixed polynuclear complex has not been formed in the eocoloration. Moreover, the reaction mechanism possidle have been noted also. 1984-03-01 2021-04-01 3