二溴邻硝基偶氮胂的纯化、性质及其钍络合物的稳定常数  

Study on the purification and properties of dibromo-o-nitro-arsenazo(DBONA)and the stability constant of its thorium complex

作　　者：徐钟隽[1] 杨亚灵 潘教麦[1] 

机构地区：[1]华东师范大学化学系,上海200062

出　　处：《化学试剂》1993年第5期257-258,共2页Chemical Reagents

摘　　要：研究了钍的新试剂二溴邻硝基偶氮胂(DBONA)的纯化方法和性质。测定的其离解常数(pK_a)、质子化常数(logK_p)分别为10.17和-4.75。求得钍络合物的组成为1:2,其积累稳定常数为27.98。Dibromo-o-nitro-arsenazo(DBONA),a new chromogenic reagent for thorium was synthesized and purified by extraction with a mixture of organic solvents.The dissociation constant(pK_a) of the first hydroxyl group on naphthalene ring in basic region and the protonation constant (logK_p) of DBONA in acidic medium were determined to be 10.17 and -4.75 respectively.The 1:2 thorium- DBONA complex formed in an excess of rea- gent is very stable in acidic medium,it gives a maximum absorption at 630nm with an overall stability constant (logK_s) of 27.98.

关 键 词：偶氮胂 离解常数 钍 络合物 

分 类 号：O657.3[理学—分析化学]