BEHAVIOR OF AMINOMETHANESULPHONIC ACID – 3D-METAL SALT – WATER SOLUTIONS.

• Datum: 2026
• Hauptverfasser: Khoma, Ruslan, Vodzinskii, Sergey
• Format: Artikel
• Sprache: Englisch
• Veröffentlicht: V.I.Vernadsky Institute of General and Inorganic Chemistry 2026
• Online Zugang: https://ucj.org.ua/index.php/journal/article/view/764
• Назва журналу: Ukrainian Chemistry Journal

Based on direct pH, redox and conductometry data, the features of the acid-base and electrochemical behavior of aqueous solutions of aminomethanesulfonic acid (AMSA) with 3d metal salts (manganese(II), iron(II), cobalt(II), nickel(II), copper(II) sulfates and cobalt(II), nickel(II), copper(II) chlorides) were established. The behavior of aqueous solutions of AMSA – 3d metal salts was studied by the ligand saturation method (equilibrium shift) at CM2+ = 0.025 mol/l; CAMSA/CM2+ = 0.08 ¸ 4.00. The composition of the formed complexes was judged by the positions of extrema and kinks in the integral pH, redox-metric curves, and extrema in the corresponding differential curves, as well as by kinks in the conductometric curves. In the studied solutions, complex compounds of the composition [M(NH2CH2SO3)]+ (I), [M2(NH2CH2SO3)3]+ (II), M(NH2CH2SO3)2 (III), [M2(NH2CH2SO3)5]- (IV), [M(NH2CH2SO3)3]- (V), are realized.  So, as the products of the reaction of metal ions with AMSA, in addition to the above-mentioned complex compounds, including hydroxonium ions, which are characterized by increased movability, the value Dk (Dk = k3 - k2 - k1, where k1 - k2 - k3 – specific of the electrical conductivity of water solutions MzAn2, AMSA and MzAn2 from AMSA, respectively) acquire positive values. Based on a developed physicochemical model taking into account the law of mass action, the material balance of AMSA and the metal, and the principle of electroneutrality, the ion-molecular composition of the studied solutions was calculated, and the concentration constants of complexation were estimated. Correlations were found between the formation constants of these complexes. The relative stabilities of 3d-metal ion complexes with AMSA correlate with literature data on similar values for taurine and its derivatives. The highest stability is predominantly demonstrated by compounds of Cu2+ ions with the studied ligand.