Studies on phthalein complexone separation and acid equilibria of phthalein complexone and alkaline earth metal complexes with phthalein complexone

Studies on phthalein complexone separation and acid equilibria of phthalein complexone and alkaline earth metal complexes with phthalein complexone

Creators Yoshino Takashi

Creators Inada Kyo

Creators Sato Fumihiro

Creators Murakami Sadaaki

The purification of the metallochromic indicator Phthalein Complexone, the potentiometric investigation of the acid equilibria and the formation constants of alkaline earth metal complexes with PC are described. PC was purified with both a cellulose column and a precipitation method. The purity of the product was nearly 100%. The acid formation constants of PC and the metal chelate formation constants of four alkaline earth metals, Mg(II), Ca(II), Sr(II) and Ba(II), with PC have been calculated. These metals form four 1:1 complex species, MH_3L, MH_2L, MHL and ML, and two 2:1 complex species, M_2HL and M_2L, in an aqueous solution (μ=0.1). The stability order for the ligand is Mg(II)>Ca(II)>Sr(II)>Ba(II).

[ISSN]0386-3433

[NCID]AA0086073X