正己烷基、正癸烷基亚氨二乙酸根离子加质子常数的测定
来源期刊:中南大学学报(自然科学版)1984年第3期
论文作者:陈超球 关鲁雄 麻三清 李玉芬
文章页码:44 - 49
关键词:亚氨二乙酸; 加质子常数; 辛烷基; 酸根离子; 酸性强度; 滴定测定; 离子强度; 电位法; 双向滴定; 实验数据
摘 要:在温度25±0.1℃及离子强度μ=0.1(KNOS3)的条件下,用pH电位法测定了正己烷基亚氨二乙酸根离子和正癸烷基亚氨二乙酸根离子的加质子常数分别为:IgK1H=10.24,IgK2H=2.33,IgK3H=1.76和IgK1H=10.19,IgK2H=3.36,IgK3H=2.21。结果表明,从正己烷基到正癸基烷亚二氨乙酸随着碳链的增长其酸性强度略有减小。
Abstract: The protonation constants of n-hexyl and n-Decyl iminodiacetate ions have been determined by the pH-potentiometric method at the temperature 25 ± 0.1℃ and the ionic strength 0.1 (KNO3). The values of the protonation constants obtained are for n-hexyl iminodiacetate ion, lgK1H = 10.24, lgK2H = 2.33 and lgK3H = 1. 76; for n-Decyl iminodiacetate ion, lgK1H = 10.24, lgK2H = 3.33 and lgK3H = 2.21. These data indicate that, of the two acidsthe, one with longer carbon chain, i. e., n-octyl iminodiacetic acid, is slighly weaker than the one with shorter carbon chain, i. e., n-hexyl iminodiacetic acid.