ピリミジン誘導体の分析化学的研究(第2報)6-アミノ-5-ニトロソ-1,2,3,4-テトラヒドロピリミジン誘導体と金属イオンとの呈色

抄録

Coloration of some metal ions with 6-amino-5-nitroso-1, 2, 3, 4-tetrahydropyrimidine derivatives and the detection limit of these metal ions were examined. Among metal ions such as Co (II), Cu (II), Ni (II), Fe (II), cobalt and iron show especially sensitive color change. Therefore further examination was made to utilize these reagents for the spectrophotometric determination of cobalt and iron. Among these reagents, 6-amino-1-methyl-5-nitroso-4-oxo-2-thioxo-1, 2, 3, 4-tetrahydropyrimidine (VI) and 6-amino-5-nitroso-4-oxo-1-phenyl-2-thioxo-1, 2, 3, 4-tetrahydropyrimidine (VIII) were the most sensitive reagents for cobalt and iron. The molar absorption coefficients of the complexs of VI and VIII with cobalt are 4.72×10⁴ and 4.48×10⁴ l·mol^-1 cm^-1, those with iron are 2.37×10⁴ and 2.51×10⁴ l·mol^-1 cm^-1, respectively. Dissociation constants (pK) of these reagents were determined by spectrophotometry. Generally, pK values of the reagents containing thioxo group were smaller than those of the corresponding reagents.