Diethylenetriaminepentaacetic acid decomposition

Rojo and coworkers have explored the use of ethylenediaminetetraacetic acid (EDTA) and diethylenetriaminepentaacetic acid (DTPA) salts as precursors for the preparation of bismuth-containing superconductors. The pyrolysis of the mixed lead-bismuth complex PbBi(DTPA)-3 H2O was shown to proceed in three stages firstly the dehydration of the complex (32-150 °C) followed by the loss of organics starting at 300 °C, and finally the decomposition of the residual ill-defined carbonates up to 500 °C affording a mixture of PbO and an unidentified new Bi—Pb—O phase. 

The thermal decompositions of the heterobinuclear coordination compounds Cr diethylenetriaminepentaacetic acid (1 1 1) (M was Mn ", Fe ", Co ", NP, Cu or ZP ") have been compared [73]. The complicated chemistry of these reactions is discussed only qualitatively but it is concluded that stability depends mainly on the chromium present and is less influenced by the ion. 

Figure 3. Decomposition of dHG in buffered media in the presence of a) catalase (1,700 U/ml), superoxide dismutase (SOD) (1700 U/ml) plus thiourea (1.0 mM), or SOD (1700 U/ml) plus benzoate (1.0 mM) b) ascorbic acid, (1.0 mM), reduced gluthathione (1.0 mM), thiourea (1.0 mM), or sodium benzoate (1.0 mM) c) phenylthiocarbamide (1.0 mM), or 2,4-Dithiopyrimidine d) diethylenetriaminepentaacetic acid (DTPA) (1.0 mM), ethylenediaminetetraacetic acid (EDTA) (1.0 mM), or no chelator.

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