Products Formed by the Oxidation Reaction of Free Ligands with Mn(III)EDTA and Mn(III)CyDTA Complexes

Abstract

In an aqueous. solution, as. ethylenediaminetetraacetatomanganate(M) (Mn(pt)EDTA) and. trans-1, 2-eyc1, hekanediaminetetraacetat, manganate(III)(Mn(III)CyDTA)act as, xidizing agents, manganese(III) ion in, these cornplexes is reduced to manganese(III)io: n, This paper deals with the ptoducts formed by the oxidation reactions occurred in the solution containing Mn(III)EDTA and EDTA (Mn(III)EDTA-EDTA system)and Mn(III)CyDTA and CyDTA (Mn(III)CyDTA-CyDTA system), The experimental procedures are as follows:
Free Iigand which is more than Mn(III)complex by a factor of 3-5 was dissolved in H20and p of the solution was, adjusted to 6, 1, Where Mn(III)complex was disso1ved in this solution C the oxidation reaction of free ligand with Mn(pt) complex occurred and was completed wif: hin 10 mint The reaction products are converted to Co(III)complexes and identi ed after separating by ion-exehange chrotnatographic technique. By these procedures, the existenceof Co(III): EDTA, Co(1 III)CyDTA, ethylenediaminetriacetatocobalt(III)(Co(III)EDTRA)and trans-1, 2-cyclohexanediaminetriaeetatocobalt(III) (Co(III)CyDTRA)complexes was confir: med. In addition, the presence of N-methylethylenediami: ne-N, N -diacetatocobalt(III)(Co (III)MEDDA)and N-methylcyclohexanediamine-N, N-diacetatocobalt(III)(Co(III)MCyDDA)complexes was suggested. HCHO and CO2 were identified polarographically and by precipitation with Ba(OH)2, respectively. The amount of each product and the effect of PbO2 are given in Tables 2 and 3.
From these results, the main reaction of Mn(III)EDTA-EDTA and Mn(III)CyDTA-CyDTA system may be written by the following Eq. (1) and (2), where Y is EDTA or CyDTA, Y, , EDTRA or CyDTRA, and Y, a radical w high is formed by oxidation with Mn(III)complexes.
Mn(III)Y+YrN Mn(III)Y+Y +CO2 (1)
Mn(m)Y+Y +H20-MnY+Y +HCHO+H (2)
MoreQver, the presence of MEDPA qnd MCyDDA suggeststhe occ ence of side reac, tigns,